Applications of Advanced Technologies in Transportation Engineering (2004)

This panel session will address the current status of ITS and related programs, as well as experiences gained in the first decade of their deployment and will examine what lies ahead in terms of advanced technology applications in meeting ever increasing demand for mobility, security, and sustainability.

Advanced Traffic Management and Information Systems (ATMIS) are widely used ITS applications nowadays for freeway and urban traffic operation and management. Developed relating on real-time traffic condition, though, they are not guaranteed to be effective in future operation periods and need to be put into short-term traffic flow scenarios for particular investigation. A process named non-OD driven simulation based on a microscopic simulator, PARAMICS, is proposed in this paper as the key technology to construct such traffic scenarios. Speed control, an incident management strategy, is put into the simulation under the predicted traffic scenario for evaluation. The evaluation results are compared to those under static the traffic flow scenario.

This paper presents a traffic flow simulator (TFS) for short-term travel time forecasting. The forecasted travel time information is useful for the pre-trip planning of the drivers. The drivers can decide their departure time and mode choice based on the forecasted travel time. A case study has been carried out in the Hong Kong Island during the AM peak period. The stochastic deviation coefficient is introduced in the case study to simulate the variation of traffic flows within the peak hour period. The purposes of the case study are: 1) to show the applicability of the TFS for real road network; and 2) to illustrate the short-term forecasting of link travel times. The results of the case study show that the TFS can be applied for real network effectively. The TFS forecasted travel times and the observed travel times are compared. The findings show that the observed travel times fall in the 90% confidence interval of the TFS forecasted travel times.

The present paper proposes a hybrid neural predictor that consists of temporal structures of Multilayer Perceptrons for encompassing traffic flow series from sequential points in a traffic network to improve short-term traffic flow prediction. Each of the temporal structures is genetically optimized to provide the optimum embedding of the series attached.

This paper presents a Geographic Information Systems (GIS) based methodology to estimate the extent and reliability of congestion using crash data. The crash data are geocoded using the street centerline coverage for the Las Vegas metropolitan area, The number of crashes on each link and the number of occupants involved in these crashes are estimated. Crash rates and average vehicle occupancy (AVO) rates are estimated. The extent is based on the link volumes and the estimated AVO rate from crash data. Reliability is computed based on the number of crashes and link volumes. These are disaggregated by time of the day, road functional class, and the area type.

This paper presents a micro-simulation method to evaluate the effectiveness of potential ITS strategies under the incident scenarios. The evaluation is conducted over a corridor network located at the City of Irvine, California. The potential ITS strategies include incident management, local adaptive ramp metering, coordinated ramp metering, traveler information systems, and the combination of above. Based on the calibrated simulation model, we implement and evaluate these scenarios in the microscopic simulation model, PARAMICS. The evaluation results show that all ITS strategies have positive effects on the network performance. Because of the network topology (one major freeway with two parallel arterial streets), real-time traveler information system has the greatest benefits among all single ITS components. The combination of several ITS components, such as integrated control, can generate better benefits.

In the past decades, modelling techniques have become a valuable decision support tool and been applied widely in transportation planning. The main principles of transport modelling are based on static and dynamic modelling principles at macroscopic and microscopic levels. They have complementary characteristics. However, little work has been directed to conduct detailed analysis, comparison or integration for different models. The gap brings out the motive of the study. The main aims of this study are to analyse and compare the characters for both static and dynamic modellings and assemble the advantages from them for the further development, improvement and researches.

Building on more than ten years experience using simulation-based training to advance the performance of personnel in traffic management centers (TMC's) throughout California, a major effort is currently underway to implement a new advanced traffic management training simulator and related curriculum. This paper describes the advanced TMC simulator facility and software system being developed to support both the training of TMC personnel and the testing of new traffic management technologies for California. A major innovation of this system is combining the new Advanced Traffic Management System (ATMS) graphic interface and information system used in actual California TMC's with the Paramics microscopic traffic simulation software. The paper is an abridgement of a more detailed working paper. The paper also reviews some of the guidelines which shape California TMC training needs, the job requirements of traffic management center personnel, the competencies required to use the technologies available to traffic managers, and the approach to develop the related training curricula. How California with its extensive experience has chosen to address this training need, in part through advanced simulation-based training, provides a useful model for other jurisdictions with congested urban areas.

Beijing, a world famous historic metropolitan city, is facing serious traffic congestion in its central district due to the ever increasing traffic demands induced by high speed economic development. To improve the local traffic situation, how to plan the road network in this area and protect the cultural relics simultaneously has become a difficult problem that concerns the government decision-makers and urban planners. The purpose of this paper is to present a case study of microscopic traffic simulation in the road network planning of Chaoyangmen-Fuchengmen Street in Beijing city. A high performance microscopic traffic simulation tool, PARAMICS (PARAllel MICroscopic Simulator), is selected to model, visualize, evaluate and compare two types of schemes, i.e. public transportation dedicated lane schemes and one-way traffic schemes. This study indicates that microscopic traffic simulation is able to provide quantitative and effective decision support for the road network planning.

This paper has investigated critical issues associated with Optimal Detector Locations for OD matrix estimation, including a discussion of limitations embedded in existing models and algorithms. A heuristic algorithm has been proposed for identifying the optimal set of detector locations under a given budget constraint for effective OD matrix estimation. Our numerical experiment results have indicated that the proposed algorithm is quite promising for potential applications.

This paper first proposes a bilevel programming model to simultaneously estimate O-D matrix and calibrate parameters in link travel time functions from observed link flows under the deterministic user equilibrium condition. It then transforms the non-differentiable bilevel programming model into a continuously differentiable nonlinear programming model by constructing a gap function. Accordingly, the augmented Lagrangian method can be employed to identify the solution of the problem.

This study proposes an approach to relate travel time variability due to stochastic network link capacity degradations to travelers' corresponding route choice behavior. We postulate that travelers acquire the variability of route travel times based on past experiences and factor such variability into their route choice consideration in the form of a travel time budget. This travel time budget varies with individuals and with trip purposes and is related to the requirement on punctual arrivals. We formulate this route choice behavior in a mix-equilibrium formulation with multiple classes of travelers. Numerical studies are conducted to demonstrate the properties of the models.

This paper studies three types of algorithms for computing all-to-one time-dependent shortest paths for all departure times on a discrete time dynamic network: the CLASSIC algorithms (direct extensions of static shortest path algorithms), the decreasing order of time (DOT) algorithm and the STEN algorithm based on an explicit network expansion. All algorithms are analyzed under the same type of compact space-time expansion networks, and implemented in a flexible and extendable framework using object-oriented programming (OOP) concepts. Two types of randomly generated networks similar to those found in real transportation systems are used for evaluating the relative performance of the studied algorithms. Our numerical results show a discrepancy between DOT's theoretical and practical computational efficiency, and STEN's computational tractability in applications involving large-size networks and demanding strict acyclicity.

A stated response experiment was performed to examine how people in Montreal in Canada are influenced by specific route attributes in the selection of routes for commercial movements. The route attributes considered included the expected driving time, the roadway type (arterial or freeway), the magnitude of a toll and the toll collection method (if any), and the probability and associated magnitude of a possible delay. A total of 242 complete interviews were conducted in two separate surveys, one with commercial drivers and the other with trucking company operators. With multiple observations of choice behaviour obtained in each interview, a total of 1885 observations of the relevant route choice behaviour were obtained. Analysis of these observations indicates that all the included attributes other than toll collection type have significant effects on route choice in the situation being considered. They also indicate, among other things, that the probability of delay has a very large impact, that the sensitivity to time in delay is greater than the sensitivity to expected driving time, and that the implied value of driving time is impacted dramatically by the nature of the treatment of expected delay. Some of these results are consistent with findings in related work done by others, which is seen to add credence to the approach being used here. Some of these results are novel, with implications for other future work.

A distribution strategy with balanced workload allocation aims to be "cost-efficient", and helps in promoting customer service levels. However, little attention has been paid to the balanced workload allocation in logistics system design problems. In this paper, a bi-level programming model has been proposed, which optimizes the distribution network in logistic systems and at the same time, balances the workload of each distribution center (DC) on delivering products to its customers, A genetic algorithm (GA) based approach has been developed to cope with the bi-level model, and it has been tested on a best "real" dataset.

Storing containers in the yard, allocating resources in the terminal, and scheduling vessel loading and unloading operations are major tasks in a container port. This paper mainly deals with the allocation of yard resources to the containers. We consider optimizing crane scheduling and weighted container movement in the yard with deterministic machine availability constraints. The problem is formulated as an NP-hard problem. A genetic algorithm is devised for solution.

This paper presents the development of a real-time system for monitoring the security of container trucks in road networks. Embedded in the security monitoring system is a container truck tracking and incident detection algorithm which relies on a combination of vehicle telemetry data obtained from Global Positioning Systems and on-board sensors to continuously monitor the route choice and car-following behavior of the driver. The performance of this algorithm has been tested in a microscopic simulation model, on a set of hypothetical scenarios, which included deviations from the approved routes, forced to travel at unreasonably low speeds, or even stopped at unexpected places in the network. The initial results indicate that the proposed system has good potential in detecting abnormal driving behaviors, with 100% detection rate, 6.0 seconds of mean detection time, and less than 0.5% false alarm rate.

This paper investigates the average trip travel time for trucks during an incident, with real-time traffic information from (1) variable message signs (VMS); (2) combination of VMS and travel time displays (TTD); and (3) dynamic route guidance systems (DRGS). The evaluation was carried out with a microscopic traffic simulation model, in a network that consisted of a 26.5 km expressway and its parallel arterials. A factorial experiment was designed to investigate the effect of five factors, which were the level of traffic information available to truck drivers, network traffic demand, incident locations, incident severity and percentage background traffic which was familiar with the network. Our results confirmed that the five factors contributed significantly in affecting the average truck travel time. There were significantly interactions between two factors with the exception of the level of traffic information and incident severity.

This paper presents a vehicle routing problem with backhauls and builds the model of the problem based on natural description. Then this paper builds a tabu search algorithm for the problem presenting a new solution indicating method and makes some experimental computations. The computational results demonstrates that the high quality solutions to the vehicle routing problem with backhauls can be obtained by using the new tabu search algorithm, and the new algorithm is also efficient and robust.

Eighteen pedestrian high crash sites were identified to evaluate various pedestrian safety countermeasures as a part of a Las Vegas pedestrian safety program. These sites were identified based on the number of crashes in the proximity of each location. Pedestrian safety countermeasures were selected based on the number of crashes and the prevailing geometric conditions. However, it is important that data be collected to study behavior of the traffic at these sites to support the selection of the pedestrian safety countermeasures. This paper discusses the collection and analysis of traffic data at the selected sites. Results obtained from the data collection efforts are discussed.

Crash reduction factors (CRFs) are used in highway safety studies to estimate how far a countermeasure may potentially reduce the number of crashes on a given roadway location. As with most states in the United States, Florida developed its CRFs based on the before-and-after approach, which requires the use of crash records and implemented safety improvement projects. The Florida Department of Transportation (FDOT) did not have a central database for safety improvement projects. Consequently, historical data for improvement projects were maintained separately at various district offices in various formats and were not easily accessible for the purpose of statewide CRF development. This paper describes an effort by FDOT to develop a user-friendly database system for the systematic maintenance of a standard set of safety improvement projects and for continued update of CRFs as new data become available. Currently, no similar system is known to exist. It may serve as a prototype by states planning to develop a similar system that is tailored to their improvement projects and crash records.

This paper presents a Geographic Information Systems (GIS) based methodology to identify high pedestrian crash sites and then select safety countermeasures based on causal factors. The methodology to select high crash sites includes identifying the problem area, the high risk zones and then the high crash sites. Two types of crash indices were used to rank high risk zones. They are based on the number of pedestrian crashes in the vicinity of the zone by severity and length of the zone. Results obtained by applying the methodology in the Las Vegas metropolitan area are discussed.

This paper presents a model and evaluation of the effectiveness of safety improvement projects funded under the Hazard Elimination Program (HEP) and the Highway-Rail Grade Crossings Program (HRGCP) at the national level based on the crash, cost and traffic data of projects implemented from 1995 to 2000, which were obtained from the states. Major findings from the study include: (1) At the national level, projects implemented under the HEP showed a 28.6 percent reduction in the number of crashes, a 61.6 percent reduction in fatal crashes, and a 17.1 percent reduction in injury crashes; (2) Projects implemented under the HRGCP resulted in a 21.4 percent reduction in the number of crashes, a 100 percent reduction in fatal crashes, and a 31.3 percent reduction in injury crashes; (3) The benefit-cost ratio was 11.3 for projects implemented under the HEP, and 8.5 for projects implemented under the HRGCP; and (4) Of the various improvement types, the implementation of illumination projects showed the highest benefit-cost ratio.

This paper presents dispatch systems using Intelligent Transportation Systems (ITS) technologies for taxi booking services. An overview of taxi services in Singapore was introduced first, that is followed by a satellite-based taxi dispatch system for booking services and their shortcomings. Two novel dispatch strategies were therefore proposed, which have proven to be efficient to improve taxi-booking services.

A vehicle guidance system has been designed for Egnatia Motorway. Egnatia Motorway spans southern Balkan Peninsula and involves approximately 2.000 km of non-urban road network, with 300 interchanges and intersections. The vehicle guidance system is based on GPS technology adapted on a fleet of vehicles. This, in conjunction with a GIS background of the road network, a telecommunication subsystem and other suitable equipment permits the efficient navigation of a fleet of patrol vehicles. A similar system is currently in use in Athens external ring road named Attiki Odos. The logical part of the system consists of algorithms that could evaluate and select an optimum route in a road network. A compass and the vehicle odometer can be used to correct extrapolated data where/when GPS signal is temporarily lost, especially when specific cargos are monitored.

After China's entry into WTO, transport industry is in a rapid developing phase, especially the multinational business. Accordingly, the Satellite Positioning System has attracted extensive concern as an important application in intelligent transportation. Imnarsat-C is a global coverage system, integrated with GPS, and equipped with the functions of positioning and data communication. The highly integrated terminal and compact facilities are its special characters. So Inmarsat is a Global Positioning System and Global Data Communication System. This article describes the constitution of Inmarsat-C system, services, application characters in transportation areas, business value and the application prospect in the future.

This paper first introduces the SOTDMA communication technology widely applied in AIS. Combined with GPS, GIS and other technologies, the paper puts forward the vehicle dispatch management information system design based on SOTDMA. At last, the advantages of such technology are explained with analysis of its system capacity.

Incident response measures are continuously being developed to deal with each incident in an effective and timely manner. One component in incident response actions is to deploy appropriate response units to the incident scene and clear the incident as quickly as possible. This paper presents a novel approach to response units dispatching in real time with a view of optimizing the process of multiple incident response management, namely minimizing total response travel time of all the response units. A GIS, i.e. TransCAD, is applied to incorporate an optimization model of response units dispatching, conduct data processing, and visualize the results. To test the proposed dispatching model, a microscopic traffic simulation tool, i.e. PARAMICS, is used to derive the real time traffic information with incident occurrences, which is then transmitted to GIS for dispatch optimization and dynamic routing of response vehicles. The results show that a GIS furnished with real time traffic information offers a powerful platform for intelligent incident response dispatching.

This paper presents the development of an automated intersection accident detection system via digital audio signal processing. Audio signals at busy intersections are the inputs to the system. The system is composed of three main signal processing stages: feature extraction, feature reduction, and classification. The results of the study show that the wavelet-based feature extraction in combination with the maximum likelihood classifier is the optimum design. The system is computationally inexpensive, and consistently results in accident detection accuracies of 95% to 100% with a very low false alarm rate in multiple stages of testing in the lab and also in a real-time real-world environment.

On the basis of traffic congestion pattern analysis and ANN information handling function, this paper develops an urban expressway traffic congestion identification algorithm based on ANN technology, and designs the special input variable for algorithm. Then algorithm is verified by actual measurement data of a certain urban expressway. The results indicate that this algorithm can identify urban expressway traffic congestion state correctly, and is highly adaptive. At the same time marked algorithm can be directly applied to identify traffic congestion of different expressway of the same city.

This paper first presents optimal pricing models of urban highway and explains optimal prices, optimal capacity and their relationship. Then the paper applies the principles of the models to traffic characteristics analysis and toll management of expressways in China. Finally the paper provides some policy recommendations.

Bus priority system (BPS) deployments have increased significantly over the past decade in North America. The purported benefits of a BPS are improved schedule adherence and overall reduced travel time. Benefits to the bus agency include reduced wear and tear on buses and improved fuel efficiency, which reduces operating costs. BPS costs can range from $8,000 to $35,000 per intersection and are relatively easy to quantify. However, other than reviewing benefits reported by other agencies, the literature lacks any formal methods for estimating BPS benefits so a formal economic analysis can be performed. This paper discusses the use of global positioning system (GPS) technology as a low-cost tool for estimating an upper bound on the potential benefit, prior to investing in the infrastructure. The use of the technology is illustrated in a case study that was conducted in Lafayette, Indiana.

Peer comparisons allow transit decision-makers to objectively analyze their operations and to identify and prioritize problem areas for management actions. An important requirement of this comparative analysis is to identify peer systems that have similar characteristics across select peer variables such as vehicle fleet, service population, and so on. This paper presents a fully automated system that can identify peer systems and peer states using data from the National Transit Database (NTD). Known formerly as the Section 15 data, NTD has been used extensively to derive values for transit performance measures. The automated system described in this paper allows a comparative analysis to be performed in a matter of minutes. Following the user specifications, the system searches for the most comparable systems using the nearest-neighbor method. Users can select the desired number of peers, transit modes, service types, and geographic areas. Users can also select the desired peer variables to determine the degree of similarity among potential peer systems. The peer variables can be weighted for different levels of importance. The analysis can be performed at the individual mode, systemwide, or statewide level. In addition to finding the peer systems for a specific system, the system also includes a procedure based on the K-mean clustering method to allow the user to divide transit systems into peer groups. Selected peer groups can then be used in peer analysis using various analysis tools that come with the system.

Traffic congestion is becoming a serious problem in more and more modern cities, Encouraging more private-vehicle drivers to use public transportation is one of the most effective and economical ways to reduce the ever increasing congestion problem on the streets. In this paper, the author presents an approach that uses K-shortest paths algorithms to compute a reasonable number of ranked shortest paths, with the ultimate `most optimal' path being selected by consideration of the preferences. Some experiments have been done based on the public transportation network of Nottingham City.

The industrial organization of different transport firms, by influencing driver behavior, plays an important role in determining how well transit systems function. Three organizational forms are defined by the type of driver contract: fixed-wage contract, lease-hold contract, and share contract. Systematic differences in the organization of transit systems across regions and countries are discussed and illustrated in the institutional context of paratransit operations in Hong Kong and the Philippines. Directions for future analysis of transport system efficiency set out.

Though Urban Public Transportation Network (UPTN) has a certain similarity to the common urban road network, it cannot duplicate the same topological model of the common urban road network owing to its unique characteristics. This paper hence presents the weighted directional multi-graph model of the UPTN as well as its modeling procedures and storage structure. Moreover, it proposes the concepts of walking transfer area and transfer cost function. The model, which fully considers the relationship of bus stops, forms the basis of network analyses of UPTN and realization of a more practical and intelligent public transportation information system.

For transit services operated by competitive private companies, as in Hong Kong, the objectives of the companies are not to minimize the total traveler and/or infrastructure construction costs, but to optimize their profits. Other than engaging in a Bertrand Game, companies may also compete via their service frequencies. As evident in Hong Kong, the intense competition has led to a very visible phenomenon — companies putting more and more buses on major (profitable) corridors, leading to significant increases in congestion on them. This study aims to analyze such externality pricing through bus tolling. The result shows that bus tolling can be a promising congestion management tool.

This research compares the traffic operations in a small network of two intersections when the signal timing plans were calculated or controlled by TRANSYT and SCATS respectively, by means of microscopic traffic simulations using PARAMICS. The three different time varying OD matrices with fluctuating traffic volume have been used in the simulation experiment. The results of our simulation evaluation have shown that dynamic TRANSYT control appears better in more cases than SCATS-based control, except in handling the relatively high fluctuation in OD in the hypothetical network.

This study aims to analyze the mechanism of risky behavior at inter-green periods and to develop a "behavior risk estimation model" which reflects driver's perception for evaluating cycle length under under-saturated traffic conditions. The risky behaviors at the inter-green period are expressed by a disaggregate logit model for each movement (through, right-turn, left-turn) using field survey data. These models are explained by delay and various traffic conflicts, which are influenced by cycle lengths. The estimated parameters of these models quantitatively indicate that longer cycle length induces more risky behaviors at inter-green periods.

The performance of local-responsive and three coordinated ramp metering methods—Denver Helper, Minnesota Zone, and Seattle Bottleneck algorithms—were evaluated using simulation. They were adapted to the study site, a 10-mile section of I-15 north of Salt Lake City. Reductions in total travel time in freeway main flow for the entire simulated freeway section during AM and PM peak hour varied from 0% to 2% depending on the metering method, traffic volume, and time of day (AM and PM peak hour). When only congested freeway links were analyzed for each 15-minute interval of the AM and PM peak hour, reductions in travel time in freeway main flow ranged from 0% to about 30%; however, in some cases, travel time increased. High reductions in travel time at congested links were offset by the increases and decreases in travel times in other links in the freeway when the entire simulated freeway system was analyzed for one peak hour. Also, all the tested metering methods increased on-ramp travel time (i.e., delay), offsetting 30% to almost 100% of the total travel time saved for the freeway main flow. The analysis resulted in mixed results indicating the benefits of these algorithms are not always guaranteed.

Road pricing has been promoted by transport economists for decades as a useful tool of solving congestion problems. A number of field studies have been reported in the literature to analyze the effect of the Electronic Road Pricing (ERP), One limitation of field studies is that it is time-consuming and expensive. This paper develops a traffic simulation-based evaluation methodology to evaluate the ERP scheme's affect on the user's traveling time and fuel consumption. A numerical example based on the road network of a town in Singapore is presented to illustrate the working the proposed methodology. The findings suggest that the proposed traffic simulation-based evaluation methodology offers a useful procedure for evaluating the effect of ERP.

This paper presents an evaluation of the advanced changeable message signs (CMSs) that have the full-matrix, full-color, and full-motion capability to depict words, symbols and images, particularly in the work zone area. The effectiveness of the advanced CMSs in reducing speed and improving safety was evaluated based on the information contained in the existing literature on the evaluation of CMSs in work zone. The compliance of the full-matrix, full-color and full-motion CMSs with the MUTCD standards was evaluated based on comparing the specification of the CMSs that were collected in the study with the relevant standards that were chosen from the MUTCD. The recommendation for the possible technological improvement for the CMSs was derived through reviewing the products of the relevant manufacturers, the display technology trend discussed on Internet, and contact with the relevant manufacturers. The recommendation for the human factor research was developed by reviewing the human factor research on CMSs and displays for ITS applications.

This paper provides an overview of the location theory, queuing models and optimization algorithms applied to a decision support system called OptimalCMS. The OptimalCMS software program has been designed to help transportation planners decide the combination of locations for Changeable Message Signs (CMS) that will provide the most benefit to users. Several components are incorporated into the program including: 1) a Geographical Information System (GIS) for displaying spatially related information, 2) a discrete network model to predict traffic flows on road sections, 3) a deterministic queuing model to predict traffic delay under incident conditions, 4) a logit model to predict driver route choice under incident conditions, and 5) a genetic algorithm (GA) optimization routine. The system is robust and readily applicable to any freeway-arterial network containing sufficient incident data.

This study identified the profiles of travelers in Long Island of New York, who were using radio and TV, their route diversion decisions based on them, and the need for having smart signs as an additional source of real-time traffic information, using binary logit and ordered probit models. It was identified in the study that radio was more extensively used than TV for obtaining traffic information. Among these travelers who listened to radio or watched TV, about 70% of them would divert to a different route to avoid congestion. Trip characteristics influenced travelers' diversion decisions only when they listened to radio. Whether travelers preferred smart signs was not related to trip characteristics.

A state space model (SSM), based on spatial and temporal Bayesian conditional independencies between traffic variables, is developed to correct/update directly measured route travel times using point-based traffic flow data. In this model, lag-free current route travel time estimates can be obtained by adjusting the lagged travel time measurements in accordance with the traffic flow measurements taken during the interval between the times the observed vehicles pass the upstream and downstream license plate readers (LPRs). The model has advantages of heightened confidence, improved accuracy, and enhanced robustness over models relying on either section-based or point-based data alone.

The paper aims to study the effects of warning message sign on traffic speed passing through work zone. The study was performed as a before and after experiment in a straight highway segment under free-flow traffic condition with six test sites, Results show that the effects of warning message sign on mean speed is affected by the distance from the sign to work zone, and in this study the sign at the distance of about 100 m has the most significant influence. Meanwhile, the results indicate that the farther the distance is, the larger the standard deviation of traffic speed will be.

This paper describes a conceptualization of a cellular phone based real-time bus arrival information system. The system is proposed to take advantage of wide-spread use of cellular phones and uses them both as a data source and information distribution media. As a data source, cellular phones are used as location referencing devices based on the principle of radio triangulation, obviating the need to install dedicated location systems such as GPS and communication links. As an information dissemination medium, cellular phones and wireless communication network are used as a low-cost platform for distributing bus arrival information. The architecture of the proposed system and its operating mechanisms and key features are described.

In this research, we implemented and presented 3GR technique, which depends on the integration of GIS, GPS, GSM and Remote Sensing, for road safety. That new technique will enhance the two main parts of road safety studies. First, in Network Screening; the new technique will help the road safety analysts to identify more accurate sites with higher-than-expected accident frequencies and Sites whose accident frequencies are not higher than expected, but which nevertheless experience sufficient numbers of accidents that may potentially be improved in a cost-effective manner. Second, will help the road analysts in Diagnosis stage to identify and focus on the real problems at specific sites. As a result of our research, we presented the advantages of that technique and discussed the future steps.

The inherent complexity of decision-making related to transportation infrastructure systems can be formalized using complex systems theory. Complex systems are characterized by: 1) many agents or decision-makers acting in parallel with dispersed control, 2) the presence of many organizational levels, 3) the ability of agents to adapt depending on the decisions made at other levels, and 4) the use of internal models to anticipate the future. We use a simulated pavement network to explore the behavior of the pavement condition, and user and agency costs, under various scenarios and relate this behavior to the attributes of a complex system. We conclude that infrastructure management systems must recognize the inherent complexity of these systems to better manage these assets.

The Chicago Transit Authority (CTA) is the second largest transit agency in the United States. Sections of this rail system are over a hundred years old and both train stations and related infrastructure are aging. In order to effectively manage and maintain station assets, the agency has developed a systematic inventory of assets and conditions. This paper describes methods to access, query and display the data using a geographical information system (GIS) and relational databases, to facilitate both strategic and day-to-day decision-making.

An attempt was made to implement a Pavement Management System (PMS) for the Town of West Warwick, Rhode Island as an initial step to develop an infrastructure asset management system. The MicroPAVER 3.2 was utilized to provide decision makers with a practical tool for the prioritization of roads and streets for cost-effective Maintenance and Repair (M&R) alternatives. A set of preliminary M&R criteria was developed based on pavement rank, minimum Pavement Condition Index (PCI) values, which are computed by MicroPAVER program using visual inspection data of roads in the network, and construction constraints. Using these criteria, optimal M&R strategies were selected and a preliminary budget analysis was performed. Two alternatives of five year M&R plans were developed for the town council's consideration.

This paper contrasts and compares the influences of single-criterion and multi-criteria route guidance systems on the whole transportation system and user performances under various market penetrations by utilizing mixed equilibrium network modeling approach. In the multi-criteria situation, users are assumed to select routes based on the tradeoffs between travel time and (monetary) travel cost, which constitute the travel disutility and can be provided by advanced traveler information systems (ATIS), while the single-criterion route guidance is based on travel time minimization. Suppose the total travel demand is given and fixed, we examine how the numbers of criteria influence both the system and user performance. The findings suggest that the traditional single criterion route guidance may overestimate or underestimate system performance and user benefits, which relies on the form of the travel disutility function form. Hence, the findings can overturn some previous outcomes in single-criterion analysis and bi-criteria counterpart such as Adler's.

This paper first designs travelers travel choice behavior (TCB) mechanism through analysis of consumer behavior characteristic and transportation service commodity particularities. Then, the author analyzes how to apply utility theory in transportation field as well as characteristics of ordinal analysis method. The paper puts forward that ordinal method is more proper in in TCB field analysis. And the author designs a macro TCB model, and finally offers a solution based on mass decision-making ordinal method.

Depending on the randomness of traffic demand and supply analysis, the paper presents the concept of unblocked reliability and the evaluation methods for road component and network system. Taking the unblocked reliability of the road system as optimization objective, the improvement optimization model of urban transportation network is built. Through the component importance analysis and genetic algorithm, the solution can be found effectively. In the end of the paper, an example is given to illuminate the practicability and maneuverability of the suggested probability assessment index and optimum methodology for the urban transportation network.

This paper presents a methodology for transit route network optimization. The objectives are to minimize transfers while maximizing service coverage. The formulation consists of representation of transit route network solution spaces that are locally and iteratively defined, and a stochastic search scheme capable of finding the expected global optimal result based on a combined simulated annealing and greedy search algorithm.

This paper describes the process and the results obtained from applying the multiple linear regression analysis approach on the data collected from the rural roads in Florida.

Digital simulation programs describe the reality with different levels of detail: models of territorial planning are essentially macroscopic (flow - variable), those for the design are microscopic (flow kinetic characteristic - variable). Study of the intersections requires models of this second kind. On roundabout, with at least two lanes, four are conditions of circulation: immission in flow, circulation on the ring with other vehicles, lane change (to right or to left) and leaving intersection. Each of these conditions requires an interpretation model that must indicates what measurable greatness (speed, accelerations, gap, lag and so on) could link to drivers behaviour and what are variations of these for different flow conditions. Into intersection each driver is to operate successively in the four flow conditions shown. From this sequence the microsimulation model obtained as link of partial submodels. As more they are accurate so many good the full program will work. For study the shown manoeuvrings has been realized a first survey on three different intersections with similar geometric characteristics, with different circulation conditions (variable flows) and with different drivers customs (the roundabouts are in two regions). The data acquisition, extraction and next analysis has furnished necessary indications to define some behavioural models. For available space in this paper is showed only an immission model: it have been tested and has given results in line with the surveys.

Based on the model of the driver's process of collecting and dealing with information of free-flow passenger cars on freeway, this article explores the factors and corresponding rules, which affected speed on a horizontal curve. A two-step model using the statistical method was developed for prediction of operating speed on horizontal curve with different joint alignments. Compared with the result of field data and the prediction of the Australia model, the two-step model has the merit of high prediction accuracy with the 85th-percentile operating speed. The model could be applied widely in the alignment design approach of operating speed and traffic simulation.

Traffic monitoring derived from space born sensors has been recently investigated as an alternative or supplement of ground based traffic monitoring techniques. Nevertheless, most of the obtained results are still inadequate for poorly understood reasons. Therefore we propose a simulation system to analyse all relevant processes of traffic data extraction based on space borne sensors. This simulation system is a flexible and highly modular software package consisting of models describing the traffic scene at the ground, the sensor signal transfer through the atmosphere, sensor carrier influences, the sensor transfer function and the final signal processing steps. This system enables the evaluation of current sensors for traffic related tasks as well as the more precise specification and optimization of future sensor and satellite parameters for traffic data collection.

There is already a worldwide research involved in Intelligent Transport Systems, Examples of those large research programs from the nineties are IVHS (Intelligent Vehicle-Highway System) in the United States and DRIVE (Dedicated Road Infrastructure for Vehicle safety in Europe) and PROMETHEUS in Europe. These research programs have given an important impetus to the future use of Artificial Intelligence in the transport field. Despite this only a relatively small number of technologies have reached the market and this has been a disappointment. A key difficulty is the distributed nature of ITS design team and the responsibilities are divided between government agencies and industry. The aim of the project described in this paper is to close the gap between the use phase and the design phase of the product life cycle, so that design of new products is augmented. This paper presents a solution for a new knowledge management support tool using Artificial Intelligence for the designer (using multi agent and ontology principles) to create and manage data flows between maintenance, warranty and design functions so that future designs can be improved. The paper commences with a brief introduction to the problem giving some background to the project. Next the paper presents a new approach to knowledge management for intelligent product design. Finally an architecture for the new system is presented. Conclusions are drawn and future work is presented at the end of the paper.

In this paper fuzzy comprehensive evaluation model of highway network is built up based on highway network reconstructing. At present, research on service level of highway network still focuses on analysis of transportation. Taking into account the characteristics of highway network in West China, this model builds up index system in adaptability of resisting disaster, pavement condition and transportation and sets up subordinate function of parabola with power of k. In addition, applications are exploited with Delphi based on the model and tested in Enshi, a region of Hubei province. The result shows that this model can be applied to some purpose.

Data imputation has been practiced by traffic engineers since traffic data programs were established in the 1930s. However, a literature review indicates that no research has been conducted to assess imputation accuracy. An examination indicates that current practices are varied and intuitive in nature. Typical methods used by highway agencies are thus statistically evaluated and compared. It is believed that study results would be useful for traffic engineers to re-examine their practices and implement more accurate imputations.

In this paper, sustainability with respect to transportation sector of the selected countries has been evaluated. Seventy nine countries were initially selected for detailed analysis for the period of 1980–1995. The key dimensions of sustainable development i.e. social, environmental, and economic characteristics are used. Firstly, a set of sustainable transportation indicators has been introduced. Then composite indices of three non-transport groups with respect to four transport modes are calculated. The composite indices are aggregated by the concordance analysis technique to achieve comprehensive transport sustainability indices of countries, and according to these values, the countries are compared and ranked. The results for the selected indicators and countries show that from sustainable transport point of view, United States is in the best place, and Sierra Leon is in the worst place among the subset of 79 countries. The results of the study depict an overall scheme for comparative assessment of transport sustainability of the countries.

Internally illuminated, photovoltaic devices have been used today in many parts of the world. Unfortunately, some of these devices have been misapplied to locations where there is not enough sunlight to adequately meet their output needs. In order to prevent such misapplications, a tool, named the Solar Calculator, was developed. The spreadsheet-based Solar Calculator program determines whether or not a particular internally illuminated, photovoltaic device, programmed for night application is likely to possess the power management needs of a given location. The Solar Calculator synthesizes weather and sunlight patterns for any given location, determines how well a particular device will perform under the simulated weather conditions, and displays the results in interactive figures. When used in coordination with a GIS, device performance can be displayed over a region, allowing the user to determine exactly where the particular device should and should not be applied.

This paper reports installation of rumble strips and the results of a driving test on a test track, and a camera observation test on a national highway. The tests were conducted to examine the applicability of rumble strips as a countermeasure to head-on collisions. It revealed that drivers of two-wheeled vehicles did not feel the strips to be dangerous when they were 12 mm deep or shallower. This depth was adopted as a standard because drivers did not rate centerline strips of this depth as dangerous. Rumble strips were judged to be an effective countermeasure to head-on collisions, in terms of smooth driving and cost-benefit, through experimental installation on a national highway.

The provision of adequate vehicle maneuvering space is an important requirement in the design of roadway intersection and other similar transport facilities. Typically these vehicle maneuvers are performed at low speeds, generally less than 15 km/h. Until recently, transportation engineers have relied on simplistic plastic vehicle turning templates or outdated computer models to verify the turning paths of design vehicles. Such methods and tools have several disadvantages and drawbacks, the most important being their limitations, accuracies and integration with widely used CAD systems. Further, AASHTO and other design guidelines make limited reference to realistic driver behavior and appropriate drive paths for low speeds vehicle maneuvers. This paper describes a CAD based vehicle simulation model that incorporates a steering rate factor that provides a more realistic model. This factor was obtained through a variety of field tests that were performed to study driver behavior. The tests involved measuring predefined semi-trailer maneuvers using manual and GPS systems to gather precise driver behavior. The results from these tests provide additional insights into low-speed vehicle maneuvers, not readily available in design guidelines such as AASHTO. With this model, better design solutions can be achieved for facilities accommodating low speed vehicle turn maneuvers.

The intelligent vehicle based on magnetic markers system is researched as the background. A fuzzy-neural network controller is designed, and the changeable area and hierarchical genetic algorithm and BP algorithm are hanged together. The fuzzy-neural network controller is trained by predigest two-wheel model. The result from simulation shows that the fuzzy-neural network controller is more astringency than fuzzy controller.

Fixed unit extension was adopted in the traditional way of actuated control, that is, waiting intervals for following vehicles remain the same. The method did not consider vehicle flow arrival rules and drivers' psychological featrues. Aiming to solve the above problems in the traditional actuated control, the paper establishes the model of changeable unit extension, and use actual data to validate its feasibility and superiority by simulation. The results obtained have the important theoretical significance and practical value for the urban traffic control (UTC).

This paper analyzes features of mixed traffic flow based on the traffic conditions of China first, then it applies artificial intelligence (AI) and knowledge project in traffic lights control to optimize the regional traffic control system and realize traffic control intelligence. It breaks the limitations of considering only motor vehicles, and take into account pedestrians, bicycles as well. This paper conducts simulation with VISSIM to evaluate the effect of traffic control system. Then a systematic PI can be constructed to reflect the integrative performance of the whole traffic control system.

Webster's method (TRRL) and ARRB method are the main timing methods for isolated signalized intersection. But they are not adequate for high density and low traffic flow, and highly saturated traffic conditions. A traffic intensity model is established in this paper as the optimized index of cycle length according to two parameters, traffic flow and time occupancy. The optimized models were given for ordinary 2–5 critical phase intersection. The validation of the method was testified from a videotape of intersection operation at a series of intersections of Chanchun in China. The value of cycle length can match the actual traffic conditions, and is better than the value computed by TRRL method or ARRB method. The c - I method can be used for cycle length optimization. A timing illustration for 4 critical phase intersection is given.

The objective of this paper is to introduce a concept of applying hardware-in-the-loop simulation for updating traffic signal timing plans. Typically, signal optimization software such as TRANSYT, PASSER among others are utilized to develop signal timing plans. These plans then must be "fine-tuned" to replicate driver behavior as well as the fact that the timing plan is based on mathematics. Presently, the fine-tuning takes place under live traffic conditions, which can lead to unsafe traffic operations, nevertheless is not efficient. In this paper, we introduce the components and configuration of the hardware-in-the-loop simulation and detail recommended procedures and steps to apply hardware-in-the-loop simulation in updating traffic signal timing plans. A diamond interchange in McLean, Virginia, USA is used as a case study to illustrate the procedures. Our analysis on measures of effectiveness (MOEs) from the hardware-in-the-loop simulation indicated proposed timing plan in example case was better than the current plan. We found that hardware-in-the-loop simulation was indeed a great tool in evaluating and fine turning signal timing plans.

This study develops the framework of a temporary signal control system using the traffic counts from movable vehicle detectors and the vehicle trajectory data from probe vehicles equipped with GPS. Also it includes not only the concept of minimizing the volume of total travel time but also CO₂ emission. In order to achieve effective signal control, signal parameters should be determined in accordance with traffic flows. However, monitoring systems, which are installed on roads as a fixed infrastructure, is usually not installed for temporary use. Therefore, after a method of estimating the volume of CO₂ emission is proposed, this study develops a framework of signal control system with movable monitoring tools and validates the movable detectors by checking the accuracy of their counts. Through the validation, we confirm that the accuracy of the observed traffic volume is fairly good but the estimated saturation flow rate has the tendency of over-estimation.

Comprehensive, up-to-date traffic monitoring is the basis for mobility information and traffic management systems. However, conventional stationary traffic data measurements are hardly able to provide the necessary data for an area-wide monitoring and cannot deliver enough information for many traffic related services. Therefore an alternative approach using positioning data of commercial vehicle fleets for traffic monitoring issues has been established. This paper surveys different prototype applications based on this probe vehicle data. Continuous monitoring and information of traffic situation via the World Wide Web accomplished by jam detection and highlighting is the basic service. Further on, vehicle route guidance systems using current and historic data achieve superior performance. Such guidance systems have been tested as modules for dynamic navigation and fleet disposition system. Finally a method to derive digital road maps and street characteristics from positioning data is presented.

This study has investigated the performance of some well known microscopic traffic flow concepts based on differential GPS data. Several models are calibrated using genetic algorithm and compared on the basis of how good the models fit with the experimental data. The General Motors' model is perhaps the most well know car following model, however there exist several contradictory findings on its parameters. The GM model is calibrated using two different approaches to identify more reliable parameters. The models mostly performed closely and fitted well with speed data compared to headway data. The interpersonal variations are found relatively higher than the inter-model variations. The GM model parameters are identified in a narrow range with R² values significantly improved.

Urban traffic flow guidance system(UTFGS) is one of the core researches of ITS(Intelligent transportation system). With the development of Vehicle Positioning, integrated technology for GPS/DR integrated navigation combines virtues of both GPS(Global Positioning System) and DR(Dead Reckoning), and makes UTFGS become the emphasis of Vehicle positioning research. This paper is supported by Major Project of China's 10th Five-Year National Key Technologies R & D Program. In this paper, a self-adaptive joint Kalman Filter based on Kalman filtering is established. The computer simulation results using Matlab prove that the method effectively realize the data fusion of the Integrated Navigation System and thus improves the precision, and reliability of GPS/DR. At last, this paper focuses on software realization of serial port communication in the integrated technology for GPS/DR with respect to software integration.

This paper proposes a Genetic Algorithm (GA) based approach for calibrating the driving behavior parameters of the microscopic traffic simulation model VISSIM. The approach defines the index of simulation accuracy as the Sum of Squared Error (SSE) of the collected vehicle speeds versus simulated vehicle speeds at the cross-sections along the road. The objective of the calibration is to search for the optimal values of driving behavior parameters that minimize the SSE. The paper presents the modeling process of this GA-based approach as well as the computer program implementing the approach. The road network around the terminals at the Intercontinental Airport of Houston (IAH) is selected for the case study. Traffic data are collected around the IAH using traffic counters and a test vehicle equipped with GPS is driven around the IAH loop to collect the vehicle's instantaneous speed data. The GA-based calibration is implemented with the collected data, and the optimal values of the driving behavior parameters in VISSIM are derived. A comparison indicates that the SSE has decreased almost 50% after the calibration. The case study has shown that the proposed GA-based approach is very efficient and practical.

In this paper, we analyze the conditional cycle time algorithms first. And then, the signal cycle time algorithm for mixed traffic flow based on bus priority has been introduced. Moreover, in order to prove the validity and rationality of the presented algorithm, a case the data of which is based on the materials investigated from the spot, has been put forward. All the relative research is to adapt to the conditions of China and put as one of the theory foundations of the ITS.

Public transportation passenger flow OD matrix is the basis of collocation of urban public transportation network. This paper applies OD matrix estimation in research on distribution of public transportation passenger flow, according to vehicle OD matrix estimation. With regard to analysis of pubic transportation travel distance, we suppose that pubic transportation travel is of medium-long distance so that few people choose it in case of too long or too short travel time. Causes of this condition are analyzed. This paper brings forward a few probability coefficients and OD matrix estimation by counting on-down passengers at each stop. Examples are particularized so the method is clearly shown. The method is simple and has been successfully used in Harbin public transportation passenger flow OD matrix estimation. Passenger flow OD matrix describing distribution of public transit travel is basis of collocation of urban public transportation network. Normally inquiry sheets are delivered to passengers getting on and drew back when they get off. Everyone should fill in the sheets according to facts. That has difficulties in practice, such as convenience and passengers willingness to cooperate. So veracity of data is not secured. If passenger flow OD matrix can be estimated by numbers of on-down passengers, then the only thing to do is to count them. And then manpower and material can be greatly reduced. OD matrix estimation stars from car OD matrix estimation, which means estimating actual sub-area traffic OD matrix with actual traffic on road network. Models in common use are Maximum Entropy Model on basis of maximum entropy, Generalized Least Squares Model on basis of least squares method. Info Minimum Model on basis of info theory, Maximum Likelihood Model on basis of maximum likelihood theory, and so on. Different estimation methods have been presented on calculation, such as Capacity Limited method, NN Estimation method, Iterative Estimation method, Operation on Chart method, and so on. These methods apply for different networks and their ranges differ. There has not been special research on distribution of urban transit passengers.

The dependability assessment (i.e., reliability, maintainability) to bus dynamic operation in transit networks is playing increasingly important role in designing routes, creating timetables, scheduling bus to trips and assigning drivers. Since failures and repairs can occur at any time and even simultaneously during the bus operation process, in-operate repair or replacement that subjects to random times to failure must be made before the maximum bus downtime is exceeded. Also, in-operate maintenance must take into account such factors as time to repair, failure rates, repair rates, and distributions of the preceding factors. In this paper, we have carried out the assessment of bus dynamic operation in special transit networks through simulation as a case study. It is shown that the system dependability assessment method through simulation is powerful and adaptable to measure the reliability and maintainability of bus dynamic operation whose subsystems/components follow to arbitrary failure and repair distributions. The emphasis of this paper is also placed on the presentation of algorithm of dependability simulation and simulation procedures.

Since the high rate of road accident fatalities which is about 22000 people each year is one of the most important problems affecting the Iran's road transportation, Transportation and Terminals Organization as the main industrial authority of road transportation affairs is working on renewal of transportation fleet and structure of roads and speed controlling in order to reduce the rate of accidents occurring in roads network. The traditional method of speed control in Iran is through application of tachograph in which the vehicle's speed, time of leaving and stoppage is recorded on paper, mechanically. In this method the drivers must submit the tachograph paper to each road police station and the police officer will give ticket to driver if he violated the authorized speed rate or got to the point sooner than the time he was supposed to. However, since the speed rate and time of leaving is taken from the mechanical component of vehicle (speedometer) and recorded on the paper, in addition to the possible mechanical errors, it makes the manipulation of results possible. The Information Technology Department of Transportation and Terminals Organization arranged an offline pilot study for the first time in Iran on 90 buses in the 431 kilometer Tehran-Esfahan route via new technologies like USB memory and GPS in order to develop a solution for above mentioned problem. In this method in addition to the information about the bus's route other information including real-time speed, average speed, unauthorized stopping points, speed violations, deviations from the predetermined route direction, bus and driver specifications, etc. are collected that in the traditional method (using tachograph) it was not possible. After implementation of the project and collection of existing information about out the buses travel routes and other marginal information, this information was entered into the Geographic Information System of the organization. The GIS was developed on the context of roads and technical constructions near the roads in the scale of 1:250000, two years ago. In this step some analysis was made to improve and control the fleet deployment situation under the GIS environment. Comparisons of drivers speed violations and accident occurred nearby and also relationship between accident happening and unauthorized stoppage of buses along the route, improvement and correction of authorized time limits of buses for traveling, are some examples.

Based on the ultimate tensile strain model, the thermal strain model, the shrinkage strain model, the creep strain model of early age concrete, and the restraint coefficient, an algorithm is proposed in this paper to calculate the restraint strain of the early age concrete. The strain criterion, namely comparing the restraint strain with the ultimate strain, is used to predict the early age cracking of bridge barrier walls. An example is provided to illustrate the procedure of predicting the early age cracking of the bridge barrier walls. This paper summarizes the control methods of the early age cracking of the bridge barrier walls according to the proposed prediction methods.

In highway bridge construction, the piled foundation of the bridge structure helps to limit its movement, whereas the embankment leading to the bridge is commonly constructed on soft soil and may settle significantly. Hence, this may cause two possible problems: the failure of bridge support piles due to lateral spreading of the subsoil and the presence of destructive differential settlements between the structure and the embankment. The use of piles coupled with geotextile reinforcement to support the embankment in the vicinity of the highway bridge structure has gained popularity very recently in South East Asia due to its effectiveness and economical advantage. A series of full-scale model tests have been carried out to investigate the contributions of soil arching and geotextile membrane-reinforcement in piled embankment. Two full-scale model tests were reported in this paper. The effect of different fill height was evaluated in these two tests. The strains in geotextile sheets, vertical load in pile as well as deformation pattern of geotextile sheet were recorded continuously throughout the tests.

Dealing with different settlement at bridge approach roadbed by geo-synthetic reinforced soil, it is not reasonable not to take horizontal displacement into account. Based on elastic-membrane theory, this paper finds out the balance equations, geometric equations, physical equations and compatible equations of geo-synthetic reinforced soil, gets the relation between vertical space and tensile force of each geo-synthetic layer, and determines the calculating method of vertical space. From the viewpoint of driving comfort, the length of geo-synthetic should be determined by the allowable different settlement ratio.

According to the characteristics of construction and the demand of construction control on long-span arch bridges, a visual implement mode of simulation computation during rib-assembling construction process is presented in this paper. It introduces the frame and function of the visualization system for simulation computation of long-span Arch Bridges construction control in details. It also provides an example of rib-assembling engineering of long-span Concrete of Filled Tubular Arch Bridges to explain that the visualization of rib-assembling construction process can reappear the spot visually and provide an effective instrument for construction control.

Road roughness is normally characterized by a summary index that applies over a length of road. Summary index measures, however, do not retain the actual contents of pavement surface roughness. This paper presents a wavelet transform analysis procedure to offer supplementary information to the commonly used road indices. Its main contribution is to offer a systematic process for identifying, extracting, and reconstructing the multiscale features of road roughness profile through simultaneous time and frequency localization. It helps to identify and locate local roughness features in the pavement, and detect the trend of roughness deterioration.

The British polish stone value or PSV test method is widely used around the world to measure the skid resistance of aggregate. It has been a British Standard for many years and forms the basis of the specification for surfacing aggregate in the United Kingdom. It has recently become a European Standard. With various modifications the test equipment is used in many other countries around the world. However, the method was developed about 60 years ago and has remained relatively unchanged since. In contrast there has been tremendous change in the amount of traffic and the stressing experienced by surfacing aggregate. This paper reports on research carried out to improve understanding between the laboratory prediction of aggregate skid resistance and actual performance in-service.

The British pendulum tester is widely used for the measurement of friction characteristics of pavement surfaces. To better understand the complex interaction between the tester and test surface, finite element simulation is applied in this paper to perform detailed analyses of rubber-pavement contact. It offers a useful tool to analyze the test behavior of the British pendulum tester. A three-dimensional finite element model is used to determine not only the skid resistance value of a test surface, but also other contact information which cannot be easily measured experimentally. The findings suggest that the skid resistance measurement of a pavement material can be determined without having to physically perform the British pendulum test. Experimental tests were carried out to verify the results obtained from the model.

There are three flexible pavement failure modes, namely, fatigue crack, thermal crack and deformation (rutting). When pavement layer materials are properly designed and constructed, the source of rutting is from permanent deformation of the subgrade. Of these failure modes, fatigue crack and rutting are related to number of load repetition and thermal crack is related to time (age) and environmental condition. Lab test proved that fatigue life is a function of maximum tensile strain of the AC layer while rutting life is a function of vertical strain on subgrade. Both strains are directly related to pavement deflection. Therefore, deflection can be a direct measurement, or indicator, of pavement performance. This report summarized data collected from DEL23 project and suggested how deflection can be applied to pavement design and pavement management.

The Federal Highway Administration's (FHWA) Truck Pavement Interaction (TPI) research program has initiated a cooperative research to investigate the potential impact of the North American Free Trade Agreement (NAFTA) overloading on US highway pavement performance. The research is in cooperation with the states of Texas, New York and Louisiana under national fooled fund study SPR2(205). In this study, major classes of NAFTA trucks with their axle configurations and load limits were first identified; then a procedure of simulating pavement damage was developed. Simulations using the calibrated pavement primary response and performance model VESYS 5 was performed. Based on simulation results, vehicle damage factors (VDF) and vehicle payload factors (VPF) for each class of truck at different axle configuration were determined. The VPF relates the total pavement damage to payload haul by a specific truck and axle configuration. It is intended to be used as an overall indicator of how highway pavement serviceability will be affected by a vehicle class transporting a known quantity of payload.

The model of tire contact load on pavement has been simplified as circular and uniform for long time, which is different from real situations. In the paper, the stresses of asphalt pavement under three types of loads are obtained through elastic finite element method. The different stress distributed laws in the contacting area between tire and pavement under different load models will also be studied. The results show that saddle shape load (axle load) can produce larger shear stress in asphalt pavement than the other loads, and the instability rutting of asphalt pavement will be increased with axle load increasing. The non-uniform load influences on stresses of asphalt pavement more significantly than the uniform load. The non-uniformity is considered to be one key factor in the development of load model for pavement analyses.

On the basis of theoretical analysis, investigation and practices, this article studies the idea, theoretical methods, principles, index system and specific evaluation models of sustainable development of road traffic, and performs comprehensive evaluation. This article puts forward suggestions regarding the policy of sustainable development of road traffic.

By comparison through cross-reference, a theory framework for post-evaluation of road network planning is established in this paper. It defines the concept of post-evaluation of road network planning and gives detailed explanation of its implications, characteristics, components, indexes and evaluation method.

This paper analyses the factors that influence a shipping investment decision within a multi-level fuzzy synthetic evaluating model (MLFSEM) framework. The difference between the MLFSEM and traditional evaluation is that the former provides a judicial value while the latter gives the economic value of a project. The appealing property of the new method is that various factors can be taken into consideration.

Through the analysis of road construction, road asphalt consumption, material resource supply, and production technology and quality of road asphalt in China, the author presents the development trends of the future road asphalt market and the problems to which suppliers should pay attention to in China.

This paper presents the tendency of advanced traffic information development and the status of urban traffic information system in China. The paper also put forwards the fundamental architecture of ITS integrated information platform and provides technical solution of principle issues involved in the platform.

Georgia Department of Transportation (GDOT) has adopted and been actively using GIS technology to improve its 18,000-centerline-mile (28,962-km) system's highway pavement management for the past few years. An Oracle client/server and GIS-based pavement management module were developed by Georgia Tech and have been successfully implemented by GDOT since 2000. This client/server-based GIS module was designed to integrate seamlessly with the Oracle central database in which the pavement condition survey data reside. Once the pavement condition data surveyed by 60 field engineers had been uploaded to the central database, the managers were able to visualize statewide pavement conditions, including the project ratings and various distresses, such as load cracking, block cracking, rutting, etc., in real time. Managers were able and can now perform spatial analyses by aggregating information with linear features into different jurisdiction boundaries with polygon features, such as working districts and congressional districts. The successful implementation of the GIS module in GDOT has greatly enhanced pavement management capability by generating data that had been previously unavailable and by obtaining pavement condition data in seconds instead of days. In this paper, examples are used to demonstrate the actual benefits of implementing the client/server-based GIS module. Also, future research about using GIS in pavement management is discussed.

This paper addresses the optimal distribution of pavement management budget among the sub-agencies of a highway organization. A typical approach by a highway agency in allocating pavement management budget to its sub-units relies on the requests submitted by the latter, and makes adjustments to meet the total budget available by means of certain pre-determined rules or formulas, or some forms of negotiation. This approach is typically subjective in nature and often does not take into consideration the pavement management needs, constraints and objectives rigorously by analytical means. An improved approach is proposed in this paper to optimally allocate the available budget of a highway organization to its agencies by considering the pavement management needs, constraints and objectives of the highway organization and the agencies under its charge. An iterative procedure between the central and sub-level agencies has been developed using genetic algorithms to arrive at an optimal solution for the budget allocation problem.

Nowadays, the development of computer network technology (NT) is so rapid that the 21st century is called ".net" century and computer network has become indispensable communication medium for human being. The application of NT in transportation infrastructure administration has also been developed these days. This paper presents a feasible approach of combining NT with Transportation Infrastructure Management System (TIMS), including building available network structure for transportation infrastructure administration, organizing reasonable data flow in TIMS based on network and designing comprehensive software frame and function of TIMS. As a result, a novel frame for TIMS based on computer network has been constructed in this paper. Furthermore, the proposed approach has been applied in building City Infrastructure Management System (CIMS) of Shanghai Municipal Engineering Administrative Department, China, which has been operated for several years successfully.

Items in pavement condition survey normally include surface distresses, such as cracking, rutting, and other surface defects. The paper presents the most recent findings on the feasibility study to conduct comprehensive survey of pavement condition through the use of stereovision technology. The existing Digital Highway Data Vehicle (DHDV) is equipped with multiple high-resolution digital cameras and related new equipment. It has been shown that it is possible to establish three-dimensional (3D) surface model of pavements for the entire pavement lane-width so that comprehensive condition information can be extracted from 3D surface model of pavements. Previous efforts in developing 3D surface models of pavements are also discussed in the paper. The paper concludes that a number of challenges remain in the implementation of such technology for field application.

To deal with the problem of pavement performance assessment, this paper puts forward a new assessment method based on the attribute mathematical theory and utilizes the Analytic Hierarchy Process to ascertain the index weights. By using the representative road data of Hengshui city in China, the paper introduces the application of the model in order to show that it is a scientific procedure and has good potential for wide applications.

The Georgia Department of Transportation (GDOT) collects and maintains an inventory of all public roads within the state. The inventory is the most comprehensive source for assessing the official mileage, condition, status, type, and use of all public roads in Georgia. Within GDOT, the inventory is an essential resource for reporting, analysis, and decision support and is the primary data source for completing the annual Highway Performance Monitoring System (HPMS) report for submission to the Federal Highway Administration (FHWA). Traditionally, field technicians have visually collected roadway characteristics while using pencil and paper recording methods. With more accessible Information Technology (IT), opportunities exist to improve operational efficiency, increase production, and enhance data quality. For the past two years, GDOT has sponsored Georgia Tech to develop a GPS/GIS-based road inventory system that re-engineers the existing paper-pencil operations. This paper presents the development of the system, which incorporates various mature technologies, including Global Position System (GPS), Geographic Information System (GIS), Distance Measuring Instrument (DMI), and data management into the system to re-engineer the current road inventory operations. The proposed system could significantly improve the productivity and the data quality for the field operation and expedite the analyzing and reporting processes.

Widening of expressways on soft ground induces many embankment and pavement distresses. In this study, centrifuge model tests and numerical analyses (such as finite element analysis) have been carried out for a widening project. Comparison is made between test data and calculated results. The development of settlement, horizontal displacement and pore water pressure in widening are investigated. At the same time, in the centrifuge model test the limit status and failure mechanism of widening is discussed and analyzed.

Severe rutting occurred in a section of National Highway Project A within six weeks of opening to traffic with rut depths observed as deep as 15 cm. The cause of the rutting has been investigated and analyzed and a new binder and asphalt mix specification were proposed to satisfy the requirements for both the heavy traffic and climatic conditions. The rut resistance and water sensitivity of the binder and failed asphalt mix were evaluated first in the laboratory. Specific requirements for a higher performance binder and mix were then proposed and incorporated in the road reconstruction project. This was followed by performance monitoring of the new pavement. The conclusions from the case study are detailed in the paper.

In order to study the physical characteristics of soil-stone mixture materials, a physical testing of 50 groups of soil-stone mixture samples is carried out, which have different water contents, proportions of the mixture, dry density and grain sizes of stone. Two models of the soil-stone mixture embankment with length of 35 m and width of 5 m were constructed. Based on wave theoretical analysis, the relationships between water content, dry density, grain sizes of stone and shear wave velocity are proposed. The theoretical calculated results of compact degree were consistent with the testing results of the filling-sand method.

A comprehensive bonding evaluation was conducted on an Ultra-Thin Whitetopping (UTW) experiment with eight full-scale pavement sections constructed with various design features. Strain responses were measured to monitor the bonding condition change during the accelerated loading. After the completion of loading, laboratory Iowa shear tests and field pull-off tests were performed to quantify the bond strength of the UTW-asphalt interface. Additional factors such as asphalt binder type, shearing direction, and the variability of the tests were also included in the evaluation.

The fatigue damage behavior of a base asphalt and various modified asphalts were evaluated by DSR tests at 5% and 10% strains. Two kinds of evaluation method of complex shear modulus (G*) were adopted. The results showed that the complex modulus G* can characterize qualitatively the damage trend of various binder and the specification of Dissipated Energy Ratio DER can be directly and explain quantitatively the damage degree of fatigue. The fatigue testing of Natural lake asphalt SMA and PG76-28 SMA results at controlled strain level showed that the SMA made with natural asphalt has higher initial flexural stiffness.

This paper introduces a statistical method to analyze traffic flow breakdown. Based on traffic flow theory and combined with mean-value change-point model, the hypothesis testing of the existence of change-points and the local-comparison algorithm to search change-points are discussed. The method is calibrated with the data from the city of Southampton, UK. An example of the applications is also included to test the effectiveness of the method. The breakdown of traffic flow is directly related with the abnormal phenomena such as road traffic incidents. It results in the discontinuities of traffic and reduces the service level. The research of traffic flow breakdown is often narrowly confined to incident detection, and there are approximately 4 kinds of algorithms: pattern recognition algorithm, statistical inference algorithm, catastrophic theory and neural network algorithm. These methods have played important roles in their past applications, and each has its shortcomings. The statistical theory of change-point is a nonlinear theory to study the breakdown phenomenon in real world. This kind of method will not change with time or location, and can be applied to various road conditions. Moreover, there is not special requirement for the distributions of traffic parameters such as traffic volume, speed, and lane occupancy.

This paper intends to find out consistent dynamic variable pricing setting and dynamic user equilibrium. The interaction between dynamic variable pricing and dynamic traffic assignment is first formulated as a model of one-level Cournot game in which the traffic authority and road users can select their strategies at the same time. Then it is formulated as a model of bi-level Stackelberg game in which the traffic authority is leader while the users are followers.

In most urban traffics in China, mix-traffic streams in urban traffic are composed of motorized and non-motorized vehicles. At present, models suitable for the analysis of traffic streams with non-standard vehicles rarely exist, and most available models are limited in scope and effectiveness. Inevitably, those existent approaches require much improvement. The characteristics and special driver behaviors of non-standard vehicles in the mixed traffic streams will be introduced in this paper, and some factors of these special behaviors to the mixed traffic modeling will be represented as well. An approach of simulating vehicles locating is adopted, and the decision-making procedure based on fuzzy logic rules control is discussed. According to me above ideas, models suitable for mixed traffic are established. Moreover, the model has been calibrated and tested with data from local area of Xi'an, a city in China.

In traffic system microscopic simulation, the processes of vehicle lane changes need to be described with high fidelity, and this is called lane change modeling. However, there are two defects in the present lane change models: one is the lack of researches on the attainable area of Normal Lane Change (NLC), the other is the ignorance of the phase during which the front wheel turning angle is 0 degree in the process of a lane change. Therefore, this paper discusses the attainable area of NLC, which provides rules to determine if vehicle reversing is necessary to perform a lane change successfully. And by analyzing drivers' behavioral characteristics at NLC, the traditional two-phase and three-phase lane change models are improved in this paper. The process or a lane change is divided into four phases: turning-angle phase, approaching phase, counter-turning-angle phase, and adjustment phase. The rationality of the model is testified by analyzing the actual images of lane change taken on the streets of Xi'an, China.

There are many reported researches considering movement behavior of vehicles. In these studies the two basic types of movement of a vehicle are longitudinal movement, car following, and lateral movement, lane changing. Dependency between car following and lane changing models and the fact that many of drivers does not consider driving lanes, necessitate developing of models that combine the car following and lane changing without considering the driving lanes. Utilizing computer simulation, the work can also be applied to conditions where lane disciplines are strictly observed. Microscopic simulation models considering the movement of individual vehicles in a traffic stream can be particularly useful for traffic analysis. This paper describes a research to develop a microscopic model for driving behavior based on the optimization process of each driver for increasing his/her speed and decreasing his/her risk of collision. In this research a basic freeway segment has been divided into cells. Individual vehicles in each simulation time step occupy single cells and their movements in these cells describe movement of vehicles in the motorway. The main concept of this research is to combine car following and lane changing models as an optimization process of drivers for increasing the speed and decreasing the risk of collision.

This paper establishes the concept model and dynamic model of optimization control from system analysis of the logistics sub-system and the social and economics system. The control variables can be determined. The correctness of the system model is tested by the example calculation.

In this paper, the origin and basic theory of traffic impact fee are reviewed, and the unjustness of American policy of traffic impact fee and the principles of cost allocation are discussed. Moreover, allocation model of traffic impact fee and two corresponding algorithms are put forward and used to gain the experimental allocation results.

Whether the system total travel cost and travel time are reduced by adjusting the work start time or not? This paper proposes the two-level model for answering the question; the upper-level minimizes the system travel cost and travel time by using the work start time as a decision variable, the lower-level models the stochastic dynamic simultaneous route/departure time equilibrium problem. Finally numerical results of a small network are provided to illustrate the behavior of the model.

The socio-economic impact evaluation for Intelligent Transportation Systems(ITS) has important theoretic value and realistic sense for the implementation of ITS schemes. On the basis of a deep study on Variable Speed Limits (VSL) schemes impact on society, economy and environment, this paper presents a comprehensive model of data envelopment analysis (DEA) for the socio-economic impact evaluation of VSL schemes and an example is introduced based on simulated project. The evaluation results show that the established DEA model not only can differentiate priority order among VSL schemes according to their evaluation efficiency index but also can judge effectively the optimal speed-limit value under different traffic volume which makes the traveling vehicles acquire the optimal socio-economic beneficial result.

In this paper, I proposed a model to evaluate the priority of highways construction. The objective highways are the Tokai-Kanjo Ring Expressway and the Gifu-Nanbu Highway, two arterial highways located in Gifu Prefecture. The two highways have been specified as different functions by the national government in the law. However, they can play a similar role in the west area of Gifu City. To solve the problems, I propose common indices to be evaluated by the different evaluators. And the comprehensive conclusion was made on the basis of the model. That was built by applying the AHP (Analytic Hierarchy Process).

With the economic growth and the improvement of living standard, car ownership in China increases rapidly. It exerts enormous pressure on transportation services. It is necessary to forecast China car ownership for urban transport planning, transport infrastructure improvement and traffic management in terms of economic level, urban configuration, traffic situation and car-concerned policies. In this paper the main factors affecting car ownership are analyzed and a model to estimate car ownership in China city with the BP neural network technology is developed. The model can take the sudden effect of some external factors such as political and economic factors on car ownership into account.

The comprehensive predicting method of road accidents based on BP neural network is proposed in this paper in view of the deficiency in predicting methods of road accidents. This method can take advantage of the useful information from every single road accident prediction method. The predicting value of road accidents is the nonlinear function of every predicting method. In consideration of the complexity of the establishment of nonlinear function, the BP neural network that has the function of high nonlinear mapping, is put forward to build the nonlinear relation in this paper. The efficiency of the comprehensive predicting method of road accidents is examined through an example.

This paper presents an automated approach to the extracting main suburban roads in IKONOS imagery, which is based on a fuzzy logic system. For each extracted object category, there are different properties that describe it, which they can be divided into geometric properties and radiometric properties. In particular, we want to show how to implement structure extraction algorithms based on fuzzy reasoning approaches. The idea is first to detect segments that are similar to road by reflectance properties. Then, the potential geometric shapes of the road are recognized by the well known Hough transform. Roads are extracted by means of fuzzy logic concepts and successive imagery analyses and image processing are able to exploit the corresponding fuzzy reasoning. The results of road candidate regions extracted automatically show that the whole approach is validated for the road extracted by the analysis of high-resolution Ortho-satellite imagery.

In this paper, a genetic algorithm for the route choice of public transit passenger is designed. This algorithm takes the psychology of public transit passengers into account, and satisfies the requirements of the large-scale traffic network under the environment of ITS, The validity of the algorithm is demonstrated by an example.

Based on the complex dynamic characteristics of ITS and hierarchical control idea, this paper brings forward hierarchical decomposing method and dynamic planning design scheme for ITS and discusses optimization of multi-phases decision-making. Integrating multi-level hierarchical method and mathematical programming, this paper also builds multi-level hierarchical programming method suitable for dynamic system.

This paper summarizes the authors' practical experiences in Intelligent Transportation Systems (ITS) Integration, a key issue in ITS deployment. Concept of ITS integration, levels of integration, system architecture for integration, and integration implementation are discussed. Finally, the paper attempts to provide recommendations at the strategic level for China ITS improvements, in particular including general considerations to ensure the success of ITS integration in China.

Automobile has become the dominant transport mode in the world in the past several decades. In order to meet a continuously growing demand for transport, one solution is to change the control approach for vehicle to full driving automation, which removes the driver from the control loop to improve efficiency and reduce accidents. Recent work shows that there are several realistic paths towards this deployment: driving assistance on passenger cars, commercial vehicles on dedicated infrastructures, and new forms of urban transport (car-sharing and cybercars). Cybercars have already been put into operation in Europe, and it seems that this approach could lead the way towards full automation on most urban, and later interurban infrastructures. China has great potentials to apply cybercars technologies because of the needs for high capacity and low environmental impact. Beijing Olympic 2008 and Shanghai World Expo 2010 could offer perfect large scale demonstrations.

A traveler has to face many problems if they go to an unfamiliar scenic spot. In order to solve these problems, a portable travel service system designed with a portable computer, a GPS board, a GPRS transceiver and electronic maps was designed. The GPS board was used to compute the position of the traveler. The GPRS transceiver was used to communicate with outsides. The portable computer was responsible for display of electronic maps, tour lines and general information about sites and establishments, etc. Besides navigation service, the system provided asking for first help and looking for accompanier. This paper introduces the organization, functions and some implementation principles of this personal travel service assistant. Practical evidences showed that it was portable, precise, economical and pragmatic.