Plan, Build, and Manage Transportation Infrastructure in China

Transport systems of most Chinese cities are in a large-scale construction period. To make the decision of planning and construction more scientific and to make urban transport management finer is the chief task of Intelligent Transport System (ITS) construction in the big cities of China. "Shenzhen Urban Transport Simulation System" is based on a multi-source data collection, taking the transport simulation technology and the model as a core, making the intelligent transport shared information platform as an information exchanging and sharing pivot, and taking the support of transport planning, decision-making analysis and transport information service as a direction.

This paper presents a GIS-based procedure to estimate congestion index (CI) at the highway link level. Using the 1995 traffic assignment data for the Lubbock, TX area, the exercise produces CI values at the network link level. These disaggregate measures of CIs are then presented in two summary forms. One is the statistical summary of aggregating link-level CI values by area type and by highway functional classes. The other is a visual summary with maps on which network links in the study area are grouped and shaded by five congestion levels measured by the CI. Benefits and limitations of using TransCAD GIS for CI studies and the like are discussed.

In Shanghai central city, numerous bicycles are currently used as the most important commuting vehicles. Due to the lack of alternative running-through corridors, many cyclists have commuted along main roads for many years where conflicts between motor vehicles and non-motor vehicles are seriously intensified as a consequence of insufficient road availability and these cyclists are also terribly exposed to traffic pollution with the rapid development of motorization. Therefore, it is necessary to provide more convenient, safer, and continuous bicycle corridor systems for cyclists. This paper proposes the notions of Pedestrian & Cyclist (P&C) Island and P&C Nucleus to remove the division by arterial roads and locate corridors for a main flow of cycling trips. Based on the principles of "Connecting P&C Island", "Passing P&C Nucleus", "Cutting and Straightening", and "Prioritizing then Attracting", the bicycle corridor network planned for Shanghai central city and the tidal management policies designed for different corridors are raised this paper.

The key to develop an accurate, reusable, and representative transportation demand model requires extensive planning prior to beginning any coding. After all, the selection of which transportation software application to deploy the transportation demand model will greatly affect the outcome of the run. For example, when applying/using the same modeling approach on transportation demand forecasting, it can be expected that two different model applications provide comparable results. However, one model application could take one tenth of the run time of the other. Run time duration is one of the many factors transportation professionals should consider. The difference is not only a matter of computer time — as the run requires professional monitoring that, in turn, transfers directly to cost. When evaluating applications, one should consider factors such as ease of maintenance and output information along with runtime duration. It may be even beneficial to convert the model to a new platform. Despite the initial investments needed to convert or redevelop transportation model, the benefits do add up expeditiously. This paper will study the reasons behind the decision of converting the Transportation Demand Forecast Model from TransCAD to the Cube software package. Lastly, the pros and cons of two different applications will be compared and analyzed.

Based on the infrastructure condition and transport technology capacity of China, the primary objective of Intelligent Transport System (ITS) development of Chinese cities is to provide technical support and decision support of the transport planning process. The construction of planning a decision-oriented transport information platform is to realize the objective above mentioned through information collection and abstraction. This paper analyzes the requirements of the system, proposes the software architecture, and discusses critical technique problems in the system development. The proposed design method was successfully applied in the Shenzhen Urban Transport Simulation System.

In this study, an origin-based (OB) algorithm is further studied to solve a combined distribution, hierarchical mode choice, and assignment network model (CDHMCAN), where the trip distribution follows a gravity model, the mode choice follows aggregate hierarchical logit structures, and the traffic assignment is a user equilibrium model. The combined model will be first formulated as an optimization model with single user and multiple mode classes, and an equivalent mathematical program is presented. Then, the proposed OB algorithm for the program is given.

Accessibility is the key concept for transportation and land use planning. However, the difficulty in computing accessibility measures has prevented it from playing a more central role in planning decision making. This paper explores the possibility to compute several kinds of job-accessibility measures with a coupling of user-friendly geographical information systems (GIS) and high performance database management systems (DBMS). The selected case is the Boston Metropolitan Region. The gigantic dataset, Census Transportation Planning Package (CTPP) for the metropolitan area, is stored in the Oracle sever. Both the database server and the GIS client are programmed to streamline the computation and the interaction with the user. This customized system can provide useful experiences for the public who want to know the accessibility impacts of various transportation and land use decisions.

This paper analyzes the relationship between the layout of highway passenger transfer terminals and urban spatial development, discusses the interactive mechanism, and puts forward a new method to research the layout of highway passenger transfer terminals. The method has been applied in the layout of the highway passenger transfer terminals in Jiangyin and obtained a good result. Thus this paper advances a new direction for the layout of highway passenger transfer terminals with the urban spatial distribution.

Traditionally, the capacity of an urban street is defined for a single direction of travel as the capacity of the through movement at its lowest point (often at a signalized intersection). The results of analysis in this paper show that this is not reasonable. On one hand, the downstream intersection approach may not be the bottleneck of the whole street due to the possible existence of many affecting factors including signal density and it's hard to judge the real bottleneck in practice. On the other hand, the capacity of a bottleneck cannot represent the street capacity effectively, and even might be a higher estimation under some circumstances. So the concept of Equivalent Capacity is proposed here, which can treat segment and its downstream intersection as an integrated system by introducing the travel speed as a variable. The primary evidence of the advantage of this new concept is given by a simple survey. Finally, the generalized definitions of flow, density and speed are used to explain the theoretic implication of equivalent capacity.

This paper explores the network properties when queues spill over network links, by examining a paradox of network expansion. In networks, each commuter simultaneously chooses departure time and travel route to minimize the travel cost including journey time and unpunctuality penalty. Using some necessary conditions of dynamic user equilibrium the dynamic network flows are exactly obtained on some small networks. Then we use a network with two origins and two destinations to illustrate an interesting paradox that is caused by the FIFO behavior among commuters traveling on a common upstream link of which the exit is blocked by one branch of downstream traffic. The comparison analysis in this example shows that point-queue models often overestimate the network performance and consideration of queuing spatial dimension in dynamic traffic assignment is necessary.

This paper analyzes the variability of resident trips and the intrinsic cause of the disparity in small cities which are at different economy levels. In the comparative analysis conclusion, economic disparity is the dominant factor which causes a difference in trip times if there was no clear difference on city dimension and layout. Seven typical small cities that are distinct in economy but similar in city dimension have been chosen in a developed zone and a general developed zone. The commonness and disparity of trip mode structure are analyzed, as well as trip purpose in both zones, the inner reason induced difference, average trip time and tolerance time of different travel modes. Verification is done by model building. The qualitative analysis and grey incident degree analysis proved that the economy is the main cause that induced different average tolerance time of small city residents. In conclusion, some suggestions are made on the basis of interrelations between traffic characteristics and economy.

It's well known that World Expo 2010 will be hosted by Shanghai, which is a metropolis with a population of over 16 million. Approximately 200 countries and international organizations are expected to participate in and more than 70 million people plan to pay visits to World Expo 2010, making it the largest of its kind in the history of World Expo. How to make World Expo 2010 become one successful global event and how to make it achieve the theme "Better City, Better Life" in such a dense traffic and highly populated city are big challenge. Construction of a multimode transport transfer system to transfer visitors from private or inefficient transport modes to efficient ones is being proposed by many experts. The specific strategies of the transfer system are studied in the paper. Firstly, the definition of Expo trip chain is put forward. The transferring characteristics of transport modes are explained by analyzing a stated preference (SP) survey of Expo visitor trip chain. The survey was conducted in two Shanghai airports. Then, experiences of the transfer systems from several previous Expos are studied. In the end, based on the trip chain SP survey and the cases analysis, the strategies for Shanghai multimode transport transfer system are elaborated.

China is currently experiencing rapid economic growth. A byproduct of this economic expansion is an unprecedented investment in the country's transportation infrastructure. However, there are two fundamental problems with the transport system that is presently being developed. First, it is largely highway oriented, which impacts future land use patterns, the environment, congestion, and issues of equity since many do not presently own automobiles. Second, the planning of transportation investments is not being undertaken in an integrated fashion that incorporates the input and objectives of all stakeholders in a given region. As a result, opportunities to enhance mobility, support economic development, and achieve sustainability objectives are squandered. Because the expansive economic growth in China is being accompanied by significant transport infrastructure investment, this is a pivotal moment for many Chinese cities. The decisions made regarding these investments have long-term implications for the environment, development patterns, equity issues, and general social well being of China. Moreover, once transport development decisions are made they are reversible only at extremely high cost. Thus, it is critical that the right investments are made at this juncture, where the character of China's transport infrastructure remains in the balance. The decisions made today will determine whether or not China achieves its goal of creating a harmonious society supportive of the environment, the economy, and the social welfare of all her people. In the context of China's expansive growth, urban transport officials and professionals need to transform their thinking and problem-solving methods in order to effectively manage a complex transportation system. They should be able to collect needed data and information, use appropriate planning and analytical methods, and develop appropriate policies and planning procedures. This will enable them to solve the traffic problems of today as well as to plan for the needs of a future given limited resources. Chinese leadership recently proposed the overall goal of building a harmonious society by 2020, a society characterized by, "democracy and the rule of law, fairness and justice, sincerity and amity, full of vitality, stability and order, and in which people and nature live in harmony." As the crucial link of economic activities, urban transport development in China must embrace this objective and coordinate with the stakeholders from all affected strata. Operating through appropriate channels, they must reflect the interests, needs and objectives of all parties, and form consensus on urban transport plans, standards and courses of action. However, urban leadership, vested with decision-making powers should understand that transport development is not only the responsibility of individual government agencies, but is also the common responsibility of all relevant parties in a region. Transport issues must be coordinated through appropriate investigation and consultation to reach an optimal policy decision that will support economic development, while taking into account people's living environment. It is only by transforming the thinking process and accommodating input from various stakeholders, that a truly collaborative transport planning process can be established. This paper sets forth some approaches that decision makers can use to ensure that planning is done in a coordinated manner and that long term objectives are achieved. They include: 1 regional development and shared vision, 2 a new management model of urban transportation planning, 3 regional transportation planning and financial needs, 4 regional transportation planning and decision-making process, and 5 regional transportation planning and sustainable development. Finally this paper provides suggestions for Chinese urban transport planning and development that could help to achieve the goal of harmonious urban development.

The airlines reorganization will accelerate the switch of the Chinese mainland civil aviation system from a former point-to-point (PP) structure to a hub-and-spoke (HS) network. In such a context, the major efforts of our paper are put into identifying hub airports in mainland China. We first analyze the HS network's competitive advantages and find four desirable hub characteristics. A three-level method is developed to incorporate the required hub features and are applied to the hub airport planning. Roles of the hubs in the planning scheme are mainly in three categories. Further discussion is extended to network adjustment as well as its dynamic evolution.

The urban external traffic hub is the important node of the correlation between urban transportation and regional transportation, the converging-dispersing traffic in a traffic hub gradually increased along with the accelerating regional integrated process and the strengthening of the correlation between city and countryside. So its influence on urban traffic couldn't be ignored. In view of some uncertainty of traffic resistance to road networks, trip production-attraction of traffic zones and trip converging- dispersing of traffic hubs in the future, this paper discusses a traffic hub distribution forecast under such uncertain conditions without an actual OD and establishes a fuzzy linear programming model which takes the least transport fee (time)as objective function, traffic hub's converging-dispersing and traffic zone's trip production-attraction as restrictions. The solution algorithms are also proposed. Compared with certain distribution model, it has been found that this model rather accords with the fact. In addition, the author discusses how to calculate the specific relations between traffic zones and traffic hubs and the resolution of different extents of uncertainty problem.

A land use transport modeling framework called PECAS, which represents Production, Exchange, Commodity Allocation System (PECAS) is introduced here. The virtue of such a system is that it places the transportation planning in the context of the whole economy by considering the fundamental root of transport demand, which is the exchange of goods, services, and labor among various activities, such as industries, services, households, and government. PECAS consists of the following three modules: Activity Allocation (AA), Space Development (SD) and Transport Supply (TS) and is linked to an aspatial regional economic model. This paper describes the design and development of such a model for the Province of Alberta, Canada in terms of its data sources, novelty, and strategies for further calibration. The framework has been applied to a number of cities, states, and provinces in North America, and it is introduced here as a better planning tool to their counterparts in China.

The international hub port construction of Yangshan is an important part of Shanghai's international shipping center development. Having little container transshipment business is a major problem that the Yangshan port faces for international hub port development. This paper first analyzes the international hub port competition situation that the Yangshan port faced in the East Asian area, finding that Busan port is Yangshan port's major competitor in the container transshipment business development and international hub port construction. The major indicators which affect the hub port competitiveness for container transshipment business are designated. The ports of Yangshan, Busan and Singapore are chosen to set up the Fuzzy-AHP mode to analyze the importance of each indicator, and then the competitiveness of Yangshan, Busan and Singapore ports is evaluated. Last, after analyzing the advantages and shortages of Yangshan port, suggestions are provided for Yangshan international hub port construction.

The selection of traffic-tools is a complicated and multi-objective system. The key to it is how to select the best solution among a series of good ones. This paper selects the traffic-tool evaluating indicators according to the principles of the indicators system. Then the value of evaluating factors is determined by using Fuzzy AHP (Analytic Hierarchy Process) against shortcomings of AHP. Finally, This paper analyzes the advantages and disadvantages of every traffic-tool through accounting. The result of this study shows that Fuzzy AHP is effective for traffic-tool selection evaluation.

In developed and fast developing countries, rising standards of living and the trend towards shorter working hours have significantly changed people's traveling behaviour. Literature reported that, during holiday periods, there were usually substantial increases in traffic volumes on highways. A clear understanding of the holiday traffic characteristics and a reasonable prediction of the upcoming high traffic volumes would significantly benefit both researchers and practitioners who are responsible for the planning, design, operation, and management of transportation networks. However, research focusing on holiday traffic has been minimal to date. The existing traffic prediction methods mainly aim on the flow during regular times. This paper is intended to first investigate the variation characteristics of holiday traffic. Then, the potential prediction errors using popular predicting methods such as time series are discussed. At last, a non-parametric method is proposed to predict the holiday traffic for different types of highways. On the basis of traffic volume data from major highways in Alberta, Canada, it is found that the performances of the proposed method are consistent and reasonable for different holiday periods and various types of roads.

Due to the simplicity and convenience of logit model, it is widely used in the field of economics and transportation. However, the precondition that the random term should be independently and identically distributed, limits the scope of its application. Focusing on the problem above and based on the good characteristics of logit model, this paper probes into its ameliorating mechanism by way of introducing the Function G(y), and studies the inherent relations between the multinomial logit(MNL) model, the nested logit (NL) model and the cross-nested logit (CNL) model, which reflects the theoretical advantages of the CNL model in dealing with the discrete choice problems. At length, the advantages and defects of the three models are compared through an example of the engineering case. The result indicates that the CNL model is more suitable for the trip mode selection than the others.

Determination of Urban taxi quantity plays an important role in promoting the development of urban public transportation and economizing road resources. Rational taxi quantity can also increase the efficiency of taxi running. Firstly, this paper takes taxi unloaded ratio, sharing ratio, average operation speed, average daily operation time and price of taxi as parameters in order to put forward a model of taxi quantity based on a calculating model of unloaded ratio. Using Geijing as a case study, this paper works out taxi quantity of Beijing, analyzes in depth the relationship among unloaded ration, sharing ratio and quantity, discusses the effect of quantity on unloaded ratio and sharing ratio, and confirms the range of sharing ratio for Beijing taxis.

After three year's operation, the review of Shanghai maglev project is mixed. One of the main critiques is that Shanghai maglev system is not fully utilized. Given the very affordable fare prices and highly congested conditions of other modes, many professionals are puzzled. The purpose of this paper is to call particular attention to intermodal coordination, which maybe one of the key factors that affect the success or failure of Shanghai maglev project. As proved by previous research, the Maglev system is designed to supplement, not replace, the existing transportation systems. The Shanghai Maglev system, as the initial segment of large transportation network systems, is bounded to connect and interact with the existing transportation network. If not supplemented by an integrated intermodal transportation network, especially efficient intermodal transfer stations, the maglev investment may become the biggest waster in transportation history.

Experimental Traffic Engineering (ETE) is a new research trend of modern traffic engineering for the purpose of the study and development of the complex ITS-related traffic systems. Those traffic systems constructed with the concept of ETE can be called Experimental Traffic Systems (ETS). This paper illustrates the main components of ETS and relevant key technologies. Finally, a case of ETS, SHGTISP (Shanghai-Grid-Based Traffic Information Service Platform) is introduced.

One of the direct reasons that cause urban traffic problems is obscure functions and unreasonable road proportion in grades. Therefore, based on the statistic analysis of trip investigation data in several typical cities, the function with double parameters is adopted to fit the relationship between Vehicle Trip Distance (VTD) and trip proportion. Furthermore, the regressing analysis of the fitting parameters is made by three infection factors. In addition, according to VTD-turnover, coupling mechanism, and equilibrium mechanism of traffic supply-demand, equilibrium equations are built to show the equilibrium relationship, between vehicle supply-demand turnovers in each grade of roads. As a result, urban road proportion in grades is deduced and the reasonability of urban road grade scheme is evaluated by an evaluation coefficient. According to urban scales and fields of the fitting parameters, fields of urban road proportions in grades are recommended in different scale cities. Finally, one example is employed to prove the effectiveness of the equilibrium relations and the evaluation measure proposed in this paper.

Transit network design is concerned with laying out transit routes, designing headways, and determining a transit network schedule. A transit route network optimization process attempts to find the route network structure with the minimum number of transfers, maximum ridership coverage, reasonable route directness, minimum access and egress times, minimum waiting and travel times, and minimum operating cost. One of the main difficulties faced by transit network optimization processes is combinatorial intractability. While research has made headways in the area of computing, the problem remains a challenging one. This paper provides a review of some methods that have been proposed to solve large-scale transit network optimization problems. The paper further explores the nature of transit service optimization problems in a large context and discusses the challenges and post research questions given the state-of-the-art and state-of-the-practice.

With the rapid development of electronic commerce, more and more people have begun to go shopping on the Internet. Price negotiation has become increasingly important for two reasons. From the consumer's view, price negotiation provides an opportunity to debate the price; from the vendor's view, the ability to negotiate the price allows for flexibility in pricing that a rigidly fixed price cannot offer. An obstacle that hinders the development of electronic commerce is that price negotiation on the Internet is not like shopping in store. In this paper, the author wants to design an agent-based price negotiation system for electronic commerce. It would allow the seller to negotiate with the buyers on the Internet. Firstly we put forward a framework of agent-based price negotiation, then we propose a price negotiation model based on equilibrium theory of game theory. Finally, the paper describes the behavior definition of agent and explains the rules for communication between agents.

Currently, freeway traffic demand during rush hours is very high and freeway traffic demand during non rush hours is very low. With variable toll pricing capabilities for cargo vehicles, traffic congestion on freeways could be reduced. Since cargo vehicle drivers have flexibility in selecting their departure time, variable toll pricing for cargo vehicles may have the feasibility in balancing cargo vehicle departure time distribution and improving traffic efficiency. In the paper, field questionnaire surveys were performed to obtain cargo vehicle drivers' behavior data regarding their departure choices if different variable pricing schemes would be implemented. Based on the survey data, variable pricing models with logit model formats were developed.

During the design and administration of expressway traffic signs, people always treat one single sign, instead of thinking about the relationships of signs on an entire network composed of different expressways. In fact, traffic signs, especially the guide signs, act as a system, which seems to have great logic. Their locations, types and information on the panels are reasonable and correlative. The paper designs the topology model of the expressway network, with the consideration of exits, entrances, interchanges and nodes of expressways, makes a logical definition of the guide signs, and discusses the relationship between the guide signs' logical definition and expressway network topology. With the logical definition, there are a lot of applications, such as automatically choosing as well as altering the guide signs that are related to the added expressway or the dropped one, and altering the relative guide signs with the adjustments of the topology of the expressway network during the expressway rebuilding and traffic administration.

In recent years vehicle-pedestrian crash is significant, and pedestrian safety has been a serious problem all over the country. The conflict between the vehicle and the pedestrian is the key to the pedestrian safety research and a road layout safety plan. Based on the traffic conflict technology, this paper sets up the vehicle-pedestrian conflict model and vehicle-pedestrian crash model in the condition of one pedestrian crossing a single lane. In addition, the Monte-Carlo system simulation is used to calculate the probability of vehicle-pedestrian collision. With the tool of spatial analytic geometry, the Volume-Speed curve is built as the condition of setting pedestrian safety device.

Highway safety is one of the most important issues in transportation. Intersections are the locations with higher traffic crashes as compared with other highway locations. This paper introduces an approach to evaluate highway intersection safety performance. This approach is fully based on the existing conditions of the intersection, including geometrics, sight distance, pavement surface conditions, traffic control devices, traffic signal timing and phasing, etc. The non-accident based approach is based on field survey to the conditions mentioned before. The approach will also result in a safety index to indicate the safety performance degree of the intersection. Meanwhile, corresponding countermeasures are ranked and recommended based on the cost-benefit analysis. Results from the real application indicate that the approach has good applicability and can be used by field safety engineers in real application.

This paper proposes a tabu search-based method to a multi-objective transit route network design problem. The whole design is performed in two phases. A route generation algorithm produces a good initial solution in the first phase. Tabu search continuously generates new solutions with route-merge, route-break and add-link operator. The external archive is used to store the non-dominated solutions that are maintained during the search process. The proposed algorithm is applied to a benchmark network for the following two objectives: operator cost and user cost. The sensitivity analyses are performed and computational results are presented.

This paper describes a dynamic model for evaluating the benefit of an Advanced Traveler Information System (ATIS). The model consists of five modules, including a route choice module and a traffic simulation module. The route choice module considers different categories of drivers' route choice behaviors with different levels of access to traffic information. The traffic simulation module simulates dynamic network conditions in response to traffic information. The dynamic model allows the investigation of a network-wide performance in a road network under different traveler information systems. Some results are provided to demonstrate the use of the model. They suggest that providing traffic information can reduce the total network delay. However, there is an optimum level of market penetration beyond which real-time information can no longer reduce delay of the network and the individual.

Probe vehicles are playing an increasingly important role in the field of ITS, and showing high value for various applications over the last decade. Recent advances of probe vehicle technologies in Japan are explored by reviewing the existing studies in both academic fields and ITS practice projects. The methods of data collection and data processing are summarized, which is followed by a brief review of recent attentions and the possible solutions. In order to enhance the feasibility of probe vehicles for real-time traffic surveillance through the entire road network, this paper tries to identify some unresolved issues that may have impacts on the reliability of obtained real-time traffic data and the efficiency of data collection. Four addressed issues include: error propagation of map matching, the bias in link travel time estimation, lower accuracy of link travel time measurement through infrequent observations, and the efficiency in area coverage.

Driving fatigue is a serious issue for traffic accident risk, for fatigue affects the drivers' ability to continue driving safely. On-line monitoring of physiological signals while driving provides the possibility of detecting fatigue in real time and is absorbing much attention in the road safety field. This study aims to identify driving fatigue through a driver's physiological signals. Physiological signals, including heart rate, skin conduction, electro- myogram, skin temperature and respiration, were collected on eight simulating experiments with 1Hz sample rate. Then wavelet transform was used to find feature vectors and a two-step fuzzy cluster analysis was developed to classify the different levels of fatigue, including alertness, a transitional phase and fatigue. Compared with the experimental data, 93.75% of the normal and abnormal states and 63.64% of the transitional and fatigue levels had been correctly identified. The results showed that such a method could provide an effective way to detect a driver's alert state level. To improve the reliability of this algorithm, more physiological signals are needed and an impersonal metrics must be used to judge the actual state of the driver.

The connectivity capacity of the topological structure of a road network is based on the structure of the urban Public Transit Network, and the performance of the connectivity capacity can reflect the rationality of the network. This article adopts the graph theory to conduct modeling for the urban Public Transit Network. With the computer simulation software TransCAD, using the space analysis function, the model based on evaluation for the connectivity of urban Public Transit Network and algorithm are provided in this article. In the end, verification for the model and algorithm provided in this article is conducted by an instance.

The UCF (University of Central Florida) driving simulator housed in the Center for Advanced Transportation Systems Simulation is an I-Sim Mark-III system with a high driving fidelity and immense virtual environments. The UCF driving simulator provides a research platform for multi-disciplinary investigations in the traffic engineering area. This paper describes several simulator studies that aimed at enhancing the quality of traffic safety and operation, including measuring drivers' minimum gap acceptance at stop-controlled intersections, analyzing the effects of dynamic sight distance problem on traffic safety, evaluating a pavement marking countermeasure for reducing red-light running, and assessing the safety benefits of variable speed limits.

This paper introduces the buildup process of train interconnecting network base on CAN bus and the process that realizes multiple locomotives network's dynamically buildup. The paper first introduces the functions and then described the inauguration and regular process of the interconnecting network, analyzes its inauguration arithmetic and describes the process of using object Petri net (OPN), finally, this paper checks the feasibility and stability designed above and give a further applications expectation.

Luminance's sharp variation at highway tunnel's entrance and exit will engender driver's visual adaptation difficulty, and even lead to traffic accident. By using EMR-8B system, a driver's pupillary changes and variety of moving fixation during entrance and exit of highway tunnels are selected as research object, the evaluation index of driving safety based on the variety velocity of pupil area and the evaluation index of visual information processing level based on the moving fixation, are brought forward. The rational range of the variety velocity of pupil areas and the index of moving fixation are also obtained, and can be used in safety evaluation of highway tunnel's entrance and exit.

Signalized intersections are among the most dangerous locations in a roadway network. The first step towards an effective solution to safety improvement is to identify the primary causes of crash occurrence. Negative Binomial regression provides a common tool for modeling cross-sectional count data like crash frequencies at signalized intersections, which assume the dependent variables are independent. Intersections could be considered as isolated when the distance between them is long. Signalized intersections, especially for those closer ones along a certain corridor, are spatially correlated and will influence each other in many aspects. Generalized Estimating Equations, which is an extension of generalized linear models to correlated data, is applied to account for spatial correlation for the safety analyses at the intersections. Rear-end crashes are the most frequently occurring collision type at signalized intersections. The paper presents a series models developed in the United States for total crashes and rear-end crashes at signalized intersections. Intersection geometric design features, traffic control and operational features, traffic characteristics, land use, and some corridor level factors are collected and their safety effects are tested. The significant factors at the different levels are identified which lead to a better understanding of crash occurrence and eventually to develop efficient safety countermeasures for signalized intersections.

Based on the investigation and analysis of intercity passenger transportation market, the paper researched on some basic problems of intercity rail transit (IRT), such as the types of intercity train (IT), the ratio of carrying traffic, etc. The paper optimized the existing methods of train operating scheme (TOS), then brought up a new model to work out the scheme gradationally, taking Hu-Ning IRT in building as an example, which validated the model as a feasible and practical one.

Even the most sophisticated Traffic Information Systems (TIS) might not be successful if driver's response to traffic information cannot be estimated in advance. Overreaction and concentration are often triggered if the estimations of driver's response to the information are not correct. Unfortunately, the analysis of drivers' response to traffic information is also very complex, because the responses of different drivers can be totally different to the same information. This paper presents the results of a study on driver's response to and evaluation of dynamic traffic information from radio and Variable Message Signs (VMS) using qualitative and statistic methods. The analysis of the survey conducted in Changchun city shows that the usefulness of traffic information from radio is admitted by most drivers and that this kind of information has a significant influence on the drivers' behavior. The analysis also shows that VMS are not dangerous to drivers if designed carefully. The analysis also revealed that congestion information and alternative route recommendations are most welcomed in general regardless of the forms of media used.

Application Programming Interface (API) is a feature available in some traffic simulation programs to allow users to customize changes in simulation such as driver behavior, ramp metering control strategies, and other ITS applications. This paper presents a method to develop an API in AIMSUN, a stochastic and microscopic simulation model, to evaluate a previously developed adaptive signal control algorithm, i.e., DP algorithm. The algorithm is coded in C++ by combing the functions and five routines available from the GETRAM extension module embedded in AIMSUN. The developed API allows dynamic link between the DP algorithm and the simulation environment. During simulation run time, the real-time traffic measurements provided by detectors in the network feed the DP algorithm that, after processing, makes the decision of signal controls. These decisions are then transferred back to the simulated network, which emulates their operations through the signal controllers. This research has demonstrated the API function is a useful tool to assess external ITS applications when these innovative ides are not supported by the simulation program.

The insufficient road resource has been unable to satisfy the vehicle demand which has been growing rapidly in Shanghai in recent years. Policy-makers, who are impressed with many cyclists' much higher traffic violations compared with motor vehicle drivers, have tried to carry out measures to forbid non-motor vehicle (NMV) traffic driving on some motor vehicle (MV) lanes of main roads to expand MV's right-of-way. However, the fairness and effectiveness of the measures have been questioned by a huge number of cyclists. From the surveys we organized and the analysis of historical Statistical data from 1986 to 2004, we conclude that in the near future, it is impossible for trips by NMV to be diverted into bus vehicles, and that cyclists should enjoy equal and equitable right-of-way because the efficiency of transporting passengers by NMV is much higher than automobiles in Shanghai. The conflicts between MVs and NMVs should be addressed by proper supervision rather than by forced administrative means.

Traffic Transfer System is an important subsystem of urban public transportation System and its evaluation can help us to find out its operational problems and solutions. In order to evaluate the layout, operation and service level of it and to optimize its planning schemes; this paper presents five evaluation indices. In practical engineering, the indices were defined; their calculating methods and grade values were given. Aiming at the fault of the traditional objective evaluation and subjective evaluation, this paper presents a combinatorial weighting comprehensive evaluation method which is an amalgamation of objective and subjective evaluation. The proposed method uses Theil coefficient to assess the relativity of the sequence and makes the combinational evaluating method to be a multi-objective programming problem. An evaluation model for a traffic transfer system is built up by means of this evaluation method and an example is given to validate the practicability of it.

Real-time information on how a road network performs is useful to a road manager and a road user. A road manager makes use of the information to manage congestion, e.g. balancing congestion in different parts of a rod network. A road user can also benefit from the same travel information to avoid congestion by re-routing or varying trip start times. Travel times are now displayed on most freeways in many cities in real time. The estimation of arterial travel times is a more challenging task because arterials are interrupted facilities with signals and other control devices interrupting traffic flow. This paper describes the ARRB Travel Time Model for estimating arterial travel times for general traffic and buses. The model retrieves traffic data from the signal control system, SCATS, each minute and has been implemented since May 2006. This paper describes the calibration and validation processes and highlights challenges for estimating travel times without identifying individual vehicles.

Operating speed is one of the most important branches in field of Road Safety. Many operating speed prediction models have been presented in the research community, while few take visual information into consideration. It is common sense that the driver's visual information would influence the speed, but it is difficult to be quantified. Based on the features of human vision, this paper proposes a novel concept— Spatial Sight-Distance (SCSD) to quantify the visual information of drivers. An algorithm is presented to compute the SCSD value abstracted from the visual information of drivers on any location of the road. The algorithm mainly takes into account three factors including the horizontal deviation angle limits, vertical deviation angle limits and terrain undulation. Based on the experimental data, the nonlinear relationship between the expecting speed and SCSD is obtained through regression procedure, and finally the operating speed prediction model is established by the point-by-point grade calibration of nonlinear relationship through TWOPAS model. The experiment results show that the operating speed prediction model based on the visual information matches the reality pretty well in the case of free flow. This operating speed prediction model based on visual information will be very useful to the research work on road safety, road safety audit, alignment assessment, accident black-pot discrimination and accident cause analysis etc.

Planning for passenger train services plays a vitally important strategic role in railway transportation. The objective of such planning is to achieve maximum net revenue for the rail operator whilst maximizing some specified functions of overall community benefit. However, there usually exists a trade-off between attracting passenger traffic and reducing operating costs. This paper puts forward a non-linear integer-programming model to optimize that trade-off. A Genetic Algorithm (GA) is introduced to solve the optimization problem efficiently. The model is described in the paper, together with the solution method. The paper also gives an example application of the proposed model by designing a passenger train service plan for China's GuangShen quasi-high-speed railway. The solution process is outlined in detail. A GA was found to be an effective technique to solve the stated transportation optimization problem. The procedure adopted here allows for practical considerations to be taken into account by providing a range of sub-optimal solutions in addition to the global optimal solution.

As the biggest water, land and air transport hub in inland China, Wuhan plays an important role in connecting east and west. In fact, Wuhan is situated as a geo-economic center in China. However, transport problems obstruct the development of Wuhan seriously. In this paper, introductions of water bus and staggered commuting hours which have been studied and implemented in Japan are proposed to cope with traffic problems in Wuhan. By the analysis of these two policies, considering geography and traffic in Wuhan, whether these policies can resolve traffic problems in Wuhan is discussed.

In order to relieve traffic congestion, the traffic signals of an artery system should be coordinately controlled. Therefore, firstly, modifying the cell transmission model and considering the delay time of the platoon dispersion of the exit lane, traffic flow models on the ordinary, merging and diverging links are developed respectively. Secondly, if common the cycle of artery system cannot be optimized, it is ineffective to optimize other parameters. So based on the relationship the of signal cycle, offsets, splits and the connection of offsets in each direction, a new optimal control system with bi-level hierarchical structure is presented. At the first level, the cycle and two-way offsets are determined simultaneously in accordance with traffic flows on the main road and secondary roads, which can cause delays of the artery system. At the second level, a split of each intersection is determined to cause less delays. To solve the new model, a modified particle swarm algorithm is advised by the changeable inertia factor at a different stage. Finally, the new model is used for the artery system and good results are obtained.

A* algorithm is a typical heuristic search algorithm, which is widely used in Game Programming, Artificial Intelligence and robotics. However, AI programmers have found again and again that the standard A* algorithm can be woefully inadequate for achieving realistic movements. A modified A* algorithm is proposed in this paper to solve the pathfinding problem for an Agent-based pedestrian simulation system. First, several heuristic functions are introduced and compared. Second, a "Trimming Algorithm" has been developed to achieve smooth straight-line movements. Third, the problem of the output path "clinging to obstacle" of the standard A* algorithm has been solved by imposing a penalty on the nodes near obstacles in map preprocessing. With these modifications, we can get a more realistic path like a human trail, the feasibility and efficiency having been proved in the simulation tests.

An official nationwide manual on intersection planning and design remains absent in China. Presently, a research group led by Tongji University is addressing its first version. Toward gaining more profound knowledge on state of the art in intersection design and operations in overseas while developing Chinese manual, this paper thus presents German and Japanese experiences. Conclusions, future studies and efforts essential for China are discussed finally.

Multiple types of transportation modes are required to cooperate through the network to fulfill the "door to door" freight express service. In the range of the entire freight express industry, highway, air and rail compete at diverse extents in the trunk corridor. Rail is capable of working better in the freight express industry with the sixth large-scale speed-up in the nationwide railway in China and the construction of the Beijing-Shanghai High-Speed Railway. This paper presents the railway orientation and its line operation mode in the Chinese freight express market through an analysis of network characteristics and Occident practices in the perspective of service network.

As the last process of traditional "four processes" management method, traffic assignment plays an important role both in theory and practice. UE traffic assignment is a basic problem in the field of urban traffic equilibrium assignment and many studies focus on it. Ant colony algorithm is a new simulating evolution algorithm which has solved many typical combinatorial optimization problems. This paper tries to solve UE traffic assignment problem with ant colony algorithm and improve the goal function value and the formula of transition probability according to the character of UE traffic assignment. The algorithm may get brush-fire optimum result and stop earlier in large scale problems. To solve this problem, this paper optimizes the formula of trail pheromone increment and use max-min ant system to limit the concentration of path pheromone into a scope. Finally, a numerical example is given to prove the feasibility and validity of this algorithm; the result is also compared with the one gotten by traditional algorithm.

Public transport offers alternative modes of transport to the private motor car. It can relieve traffic congestion and reduce air pollution from road transport. For these reasons, the idea of development of advanced public transport is well accepted in Switzerland. Each year from 2004, there is a new tramway built in Geneva. Extension of tramway will be continued in the coming years. To make public transport more reliable (less delay and timetable respecting), the transit priority strategy (such as transit lane concept and transit priority treatment measures) is always applied at signalised junctions. A signalised junction where the transit movement may have favourable green (for example, green will be given to a transit movement when it arrives at junction) is a transit priority oriented signalised junction. It is a type of intelligent signalised junction. Based on more than ten year's experiences over 70 intelligent signalised junctions' design and realization in Geneva, the author presents in this paper the main steps of a transit priority oriented signalised junction's design and its realization. The following main steps are discussed: junction control strategy study; determination of control equipment; junction detail signal design; controller programming and test, analyse of recording data and evaluation of the effectiveness of the transit priority signal control. The development of useful tools for intelligent signalised junction design and a new signal group oriented traffic controller are also described. Some further developments and researches are suggested.

With the development of economy, Shanghai, the biggest city of China, suffers from severe traffic congestion. The elevated expressways in downtown Shanghai are highly clogged during peak hours as well as off-peak hours. To improve traffic situation of elevated expressway without adding more infrastructure and creating negative impacts on environment, an ATMS for elevated expressway has been established. Considering the complexity of urban elevated expressway network, an integrative architecture is proposed in this paper for system development of ATMS. This integrative architecture includes traffic management strategy, physical framework and main functions of ATMS. The field equipment part of this ATMS consists of real-time traffic data collection subsystem, traffic guidance and control subsystem, and real-time surveillance subsystem. This paper gives the detailed introduction of the features of these subsystems. In addition, it gives the evaluation results for ATMS demonstration project and gives recommendations for further research.

In order to increase the capacity at a signalized intersection, cycle lengths in many large cities in Mainland China are extended continually to "match" the traffic demand. However, longer cycle time does not always bring up increasing capacity, especially at those signal intersections with short approach lanes. This research attempts to derive a crucial factor to help deciding whether the extension of the cycle length for a certain signalized intersection would be effective or not. It was found that for an approach with short lanes, the relationship between the capacity and the cycle length depends on the saturation flow rate of the normal lanes versus that of the short lanes, the effective length of the short lanes, the lose time and the cycle length itself. The criteria to estimate the above relationship were presented and validated through numeral computing.

Optimization of signal timing plans is normally based on operation research methods. In this paper, a new optimization technique is introduced. As a basic idea, the signal timing plan is considered as an analogy to a construction structure. Therefore, all of the basic concepts and methods of the structural analysis can be used for solving the optimal timing of the signal timing plans. The only difference compared to the conventional structural mechanics is the non-linear "elasticity" of the signal timing plans. As an objective function of the optimization, either the sum of delays or the fuel consumption or other variables like air pollutants can be used. For the solution of this equilibrium problem, algorithms from structural engineering can be applied. These algorithms are very efficient in term of computation converge very quickly. Therefore, rather complex intersection structures can be optimised with quite short computer times. Also an on-line rolling optimization of signal timing plans with measured traffic flows can easily be realised. This technique is proven to be very effective for practical applications. The new method is capable of extending the optimization from single intersections (including optimization of the cycle time) to network of traffic signals and to traffic-actuated controllers.

At the design phrase, it is difficult to determine a reasonable number of tracks of passenger rolling stock in a servicing yard. This article focuses on a new idea of simulation technology to find a solution. Using ARENA software, a simulation model for handling passenger train maintenance and overall preparation services is established on the basis of a fixed position working procedure. Several modules are developed and statistical indexes are designed. Finally, an operational evaluation of the design of a 14 track yard is made with a practical case of the passenger rolling stock servicing yard of Shanghai-South Railway Station. Fifteen or more tracks should be equipped with suitable service groups to synchronize all work.

Transit signal priority is a key method to improve the reliability and level of service of transit systems. Under the condition of multiple priority requests, the serve sequence dramatically affects the efficiency of transit signal priority strategies. The multiple priority requests are classified into two kinds: multiple requests for single phase and multiple requests for multi phases. The decision tree is used to optimize the service sequence of these two kinds of multi requests. Minimizing the average person delay of all priority requests is adopted as decision objective. The results of a case study show that the conventional response sequence, First-Come, First-Served, is not guaranteed to be the best solution. Based on the decision objective of minimizing the average person delay of multi requests, the decision tree method can generate optimal serve sequence.

Significant development has been made by many operating agencies throughout the China in the last decades, in deploying the urban Intelligent Transportation Systems (ITS). This paper describes efforts needed to (1) develop the practical implementation framework, (2) develop education program and training packages, (3) devise practical traffic signal operation evaluation mechanisms, (4) deploy the education and training workshop(s), and (5) develop web-based Community of Practice (COP) and peer-to-peer support network, in order to improve the skills for attacking the traffic signal timing, timing synchronization, and traffic congestion management problems currently exist throughout cities/counties in China.

Variable Message Signs (VMS), a collective route guidance information provision, are widely used in urban traffic in most metropolitan areas in China, which actually affect drivers' route choice behavior. In this paper, a disaggregate choice analysis method is used to describe changes in drivers' route choice behavior. Logit model, based on guidance utility, is applied to determine probability of route diversion, in which, not only traffic condition information characteristics are included, such as survey time, congestion level, but also drivers' characteristics are taken into account, such as gender, age, driving experience. A case study is presented by taking drivers' responses to VMS on Shanghai out-ring road, where a lot of stated preference data and revealed preference data is surveyed. Parameters of the above logit model are determined using those SP and RP data. The result shows congestion level and age are important factors that affect route diversion probability.

ITS technology applied in Expo is not only in favor of meeting the traffic demands by Expo participants and solving the traffic problems, but also an important approach in demonstrating the development and promoting advancement of ITS. Based on the ITS technology development and traffic characteristics analysis of Expo, this paper analyzed the different user groups' demands for ITS after defining the Expo users' requirements. Meanwhile, starting from the existing and potential possibilities of adopting info exchange technology, we are building the architecture model and information flow of ITS for World Expo 2010 Shanghai.

The use of simulation programs to assess the impact of measures on traffic safety is possible, but needs a double validation: the simulation should be valid for the properties that influence traffic safety and there should be a criterion and observable measure that correlates well with traffic safety. Both requirements are difficult to satisfy for most simulation programs. Accidents happen too frequent, but still the causes of accidents are not always easy to identify and the accident process is often very sensitive to small influence factors and cooperative affects. Therefore, the use of simulation for the determination of effects of measures and technologies on traffic safety is often based on believes and expert knowledge: if in a driving simulator the number of errors made by a driver is counted and when this is considered as a measure of the unsafety, the simulation has at least face validity a logical consistency with the expected relationship with traffic unsafety. In macroscopic simulations, like e.g. traffic assignment programs and traffic flow models, the empirical relationship between macroscopic characteristics of the traffic situation and safety can be used to predict changes in accident after changes in the traffic conditions. Still this is at best an estimate of the expectation value and not accurate prediction of the change in number of accidents. For microscopic simulations no validated measure for safety exists, as far as the author knows. The time-to-collision is often used, sometimes modified to the TIT or TET, but the validity as safety predictors has still not been proven. A most difficult to assess is the rebound effect, the effect that drivers change their behavior after new technologies become available or certain measures have been taken. This adaptation leads to more risky behavior which may annihilate the effect of the improvement.

The study on mass performance in Urban Rail Transit (URT) stations helps to enhance efficiency and security of passenger service, and supports design and amelioration of stations. The procedure of Mass Service Routing and Assignment (MSRA) is similar to the routing of ant colonies looking for food. This paper analyzes the service network of URT stations and the hierarchical structure of the mass, and brings forward Dynamic Multiple Ant Colony Optimization (DMACO) to study MSRD. In DMACO, the mass is divided into colonies corresponding with passenger flows, and original Ant Colony Optimization is used in all the flows simultaneously. The effects, from other colonies, guidance, capacity of network, and preference of ants to pheromone, are imported in state transition rules, in order to meet MSRA in condition of multi-hierarchy, multi-process passenger service in a URT station.

Searching for a parking space has become an unavoidable task for drivers in Shanghai CBD. Providing drivers with parking availability information will reduce their searching time and thus reduce traffic on the road during congested periods. However, there is a need for more field study/surveys in order to improve our understanding of parking behavior and drivers' reactions to the parking information provided. The main goal of this paper is to analyze parkers' behavior in choosing a parking lot in the Shanghai CBD and to develop a better understanding of the users' need for parking information. The Xujiahui Area, one of the CBDs in Shanghai where a Parking Guidance and Information System (PGIS) was deployed in December 2003, has been chosen to conduct the case study. In April 2006, a scientifically designed parking survey was carried out to collect data about parkers' revealed-preference and stated-preference. The results of 783 drivers' responses are used in this study. The analysis of this study shows that parking difficulty mainly resulted from the lack of parking information. The drivers' behavior in choosing a parking lot is mainly influenced by walking time, availability of parking spaces, parking fees and trip purposes. In particular, this is the first time that a study has investigated the performance of a PGIS operating in China.

This paper presents a novel perspective of driving simulator application on traffic safety: exploring driving simulator as a traffic safety test tool at signalized intersections. In support of this concept, a signalized intersection with as many important features (including roadway geometries, traffic control devices, intersection surroundings, and buildings) was replicated into the UCF (University of Central Florida) driving simulator. A series of driving simulator experiments for the intersection were conducted to determine if the subjects' speed behaviors and traffic risk patterns in the driving simulator were similar to what were found at the real intersection. The experiment results showed that the advanced driving simulators can be used as a valid tool to assess traffic safety at signalized intersection.

Some researches and reports has indicated that ETC system does contribute to traffic accidents at toll plazas. Oppositely, others showed that ETC system does improve the traffic safety at toll plazas. There are still no definite conclusions on safety impact. For establishing a basis of evaluating the benefit of ETC, the impact of ETC on traffic safety at toll plaza was studied in the paper. Firstly, related literatures were reviewed. Then the safety conditions at a toll plaza and the contributing factors of ETC to safety are discussed. Based on traffic crash data collected, it was indicated that ETC may result in the increase of crash number and more severe crashes could happen due to the high passing speed at ETC gates.

An adaptive control strategy called Piecewise Optimum Delay Estimation (PODE) has been developed and tested in this paper. The limitations in the existing adaptive control strategies are reviewed and used as the basis for improvement. By using real time field data for traffic demand estimation and through piecewise optimization, PODE dynamically searches movement combinations for phasing and timing decisions that minimize system wide delay. Preliminary results show that PODE is able to considerably reduce delay over actuated control. Its performance consistency, especially in congested and oversaturated conditions, has demonstrated PODE's competitive strength among other adaptive control strategies.

This paper presents the finding from a full-scale accelerated pavement testing study on three flexible pavement test lanes. The three lanes generally varied in their base (or interlayer) and sub-base materials, but had similar hot mix asphalt top layers. The objectives of this study were: (1) to determine the effectiveness of using an untreated reclaimed asphalt pavement (RAP) interlayer in lieu of stone interlayer in a soil-cement asphalt pavement structure; and (2) to investigate the performance of soil cement sub-base layers by varying layer thickness and cement content. The accelerated test was terminated due to severe rutting developed on each of test lanes. The field performance was monitored using Falling Weight Deflectometer (FWD) and DYNAFLECT tests as well as rutting and surface cracking measurements. This study concluded that an untreated RAP interlayer in a soil-cement pavement structure was as effective as the crushed stone interlayer. In addition, the rutting performance of a soil cement layer was found influenced more by layer thickness than by cement content.

The temperature distributions in asphalt pavement have a great effect upon the bearing capacity and performance of asphalt pavement. The Transportation Engineering School of Tongji University started comparative research about 5 years ago. Thermal sensors were installed in several pavement sections in different regions to monitor the temperature fluctuation inside the pavement structure. Based on data from this research program and related weather information, the application of SHRP and LTPP pavement temperature prediction model in China is verified. Then statistical temperature prediction models established through regression analysis are introduced in detail. Compared with the other existing prediction models, the models show comprehensive applicability and excellent accuracy.

The fractal model of grain size distribution, aggregate volume and aggregate pore are deduced by using the theory related to fractal geometry. The results of the road performance tests showed that the fractal dimension of aggregate volume is strongly related to air voids, dynamic stability, TSR (retained tensile strength), structure depth and the failure strains of a low temperature bending test. The influences of the fractal dimension of aggregate volume and asphalt aggregate ratio on road performances were appraised by using grey relation analysis method. The correlation model of pavement performance and fractal dimension of aggregate volume is deduced by using the correlation analysis method.

Due to its low impact on overall highway system in case of failure, low volume road design and construction acceptance are very often ignored by highway agencies. The negligence more often than not is due to lack of staff to handle these "minor" projects. From a macro highway system point of view, impact of low volume road failure is not significant. But for users who depend on this system to support their daily life, a failure is detrimental. There is a need to develop a simple, easy to follow, and reliable procedure to design and accept low volume roads. Data collected using a Dynamic Cone Penetrometer (DCP) on several construction projects show that such a procedure is possible. A DCP base low volume road design and construction acceptance procedure is proposed. This procedure is simple enough that a reliable road can be designed and constructed under the supervision of a junior engineer.

As a type of polymer material, bitumen ages easily under ultraviolet (UV) radiation conditions. However, the effect of UV aging is still not very clear. This paper discusses the behavior of UV aging on asphalt performance of five binders and mixtures by experiment. The results show that binders' physical aging behavior is highly consistent with its rheological properties; the low-temperature flow deforming ability of asphalt degraded remarkably after UV aging. There are close correlations between the mixture's low-temperature deforming ability and the binder's stiffness, and the mixture moisture stability evaluation index (i.e. TSR) and binder's penetration, respectively. In addition, the paper points out that binders' aging behaviors can be well explained with its chemical character: aromatics and resin are the two decisive chemical components of a binder for its anti-ultraviolet aging ability.

In order to improve the shortage in calculating principles and methods of chevron spacing, and to increase the dependability for four visible chevrons and the accuracy of road curve radius perception, the authors have concentrated on six basic curves under different design speeds according to the Design Specification for Highway Alignment in China. They have taken into account the five factors including the angle and distance of acute cone vision, scattering angle and distance of the vehicle lamp, chevron legible distance, driver's eye focus location, and deceleration distance when a vehicle approaches the curve at a high speed. The goal is that four chevrons can be seen at the same time at the edge of the median of a dual two-lane highway. The five characteristic points of the basic curves are set as the chevron setting jumping-off point. The model of chevron spacing is established according to the curve's integral characteristics and by the tangent off-set method. Then with the minimum as the reasonable spacing, and based on the reasonable setting space of the basic type of curve under different design speeds, the ultimate chevron spacing model is achieved. In addition, this paper discusses assumptions about problems about curve inducement in multi-lane, and dependability for four visible chevrons at the same time, and so on.

In 2004, the number of scrap tires in China reached 120 millions and this number is increasing by 12% every year. There is a considerable demand for using scrap tires in civil engineering applications. This paper presents a description of asphalt rubber technology and its potential use in China as an alternative use for scrap tires. Asphalt rubber has been used in the United States of America and several other countries for many years and the asphalt rubber products have been shown to provide significantly improved engineering properties over conventional paving grade asphalt. Consequently, pavements constructed with asphalt rubber mixes have many benefits such as improved durability and improved resistance to surface initiated fatigue and reflection cracking, improved aging and oxidation resistance due to higher binder contents, thicker binder films, and anti-oxidants in the tire rubber. The use of asphalt rubber is not only an innovative way to recycle used tires that otherwise would be wasted, but also one of the most effective methods in extending pavement life through the improved engineering properties of the asphalt rubber products. China has thousands of miles of semi-rigid asphalt concrete and portland cement concrete pavements in need of maintenance and rehabilitation. This paper presents the latest advances in the asphalt rubber technology and the state-of-the-practice and discusses various asphalt rubber products used by the California Department of Transportation and their potential use in China.

Till now, only dry process is used to manufacture asphalt rubber (AR) in highway in China. This paper describes the production of asphalt rubber with wet process and the application of asphalt rubber for concrete pavement overlays. This paper presents: (1) selection of crumb rubber and base asphalt; (2) producing parameter tests that affect the properties of asphalt rubber; (3) evaluation of performances of asphalt rubber Stress Absorbing Membrane Interlay (AR-SAMI); (4) evaluation of different design methods of gap graded asphalt rubber mixture... After a series of tests, some conclusions were drawn from this research. Asphalt rubber using truck tire crumb rubber has better performances than that using car tire crumb. Using #20 mesh size crumb rubber can give better asphalt rubber than #40 mesh and #60 mesh crumb rubber can. As for base asphalt, asphalt rubber using penetration 70 base asphalt has better high temperature performance than that using penetration 90 base asphalt, but its low temperature performance and fatigue resistance were not as good as asphalt rubber using penetration 90 asphalt. AR-SAMI had good fatigue and shear resistance. Gap graded asphalt rubber mix designed using Superpave Gyratory Compactor(SGC) method had better rutting and low temperature cracking resistance than that using Marshall method.

The main objective of this research study is to find a new technical method for producing a homogeneous and storage-stable polymer modified asphalt paving materials instead of the dynamic vulcanization process. A simple machine work under heat and pressure was designed and manufactured for this purpose. In this paper, polypropylene-modified asphalt is reported as a justification for this method. Seven different blends including control mix were subjected to binder testing such as rheological tests, as well as to some other tests related to the homogeneity of the system. Optimum asphalt content was obtained by Marshall method and used in all the modified mixes. The engineering properties, including Marshall stability and indirect tensile strength were determined. Research results indicate that modified binders showed a higher softening point, keeping the values of ductility at minimum range of specification of (100⁺ cm), and caused a reduction in the percentage of weight loss due to heat and air (i.e. increase durability of original asphalt). The results indicated that the inclusion of produce polypropylene by this method with asphaltic concrete mixtures gave a quite satisfactory result in terms of stability and other Marshall properties, and increase in indirect tensile strength.

The concept of perpetual pavements has been well documented in Europe and North America for several years. This paper presents an experiment to design and construct perpetual pavement sections to carry very heavy loads with a design single axle of 19 tonnes. The main objective is to construct pavement sections designed using different methods, to measure their response and predict performance. The experiment has three objectives: 1. Evaluate structural design methods. 2. Evaluate asphalt mix properties to carry heavy loads. 3. Characterize traffic loads being applied to the pavement. Five pavement sections were built on a new motorway in Shandong Province, China. One section was designed using a tensile strain at the bottom of the pavement of 70 microstrain under the design load. Another was designed using the same principle except 125 microstrain was used as the limiting strain. A third section also used 125 microstrain but was constructed with mixtures that are more strain tolerant. Two composite sections were built with stabilized soil and aggregate layers under hot mix asphalt. All sections contain embedded instrumentation to evaluate pavement response under known loads. A weigh-in-motion scale will categorize the number and types of trucks as well as the axle loads to which the pavement is being subjected. This paper presents the design and construction of the experiment and the measured response of the pavements to known loads. A methodology is also presented to estimate the expected life of the pavement sections.

A test chamber with degrading materials on automotive emissions is developed to test the degradation efficiency of automotive emission factors with four different contents: 2%, 3%, 4%, 5% of nano titanium dioxide photocatalytic materials made by dispersed mechanism methods, which are mixed round with high shear, ultrasonic wave and ultrasonic wave dispersant. The sample is the emission when the vehicle is on idle. The average degradation efficiency of different dispersed nano titanium dioxide materials on NO_x, HC, and CO are calculated according to the equation of degradation efficiency. The experimental results show that the photocatalytic materials with four contents of nano titanium dioxide, made by different dispersed methods, have certain influence on NO_x, HC, CO and the trends of the degradation are the same. Nano titanium dioxide made by ultrasonic dispersant has the best degradation efficiency on NO_x of automotive emission. To the nano titanium dioxide made by high shear, ultrasonic wave and ultrasonic dispersant, the optimum content of nano titanium dioxide of degrading NO_x, HC, CO on automotive emission is 5%, 3%, 2%; 5%, 3%, 4%; 5%, 2%, 3% respectively.

Coverage is an important parameter in the airport pavement design. Coverage calculating method in CBR pavement design method of FAA and UFC are detailed. In those methods the load repetitions can be considered using pass-to-coverage ratio. The ration is calculated base on the wheel-path distribution on pavement surface, which is not corresponding to the damage caused by the stress or strain within pavement depth. The calculating position is moved from surface to the top of subgrade in LEDFAA 1.3, while the lateral distribution of strain is considered as uniform not a normal distribution. There are no specific definitions of coverage in the specifications for asphalt concrete pavement design in China. For a pavement design method which can satisfy the New Generation Large Aircraft, such as A380, the coverage should be considered base on pavement spatial responses. The general pavement design concept advanced by Monismith gives a good idea to develop coverage calculation method.

In the USA, many highway agencies have successfully implemented the Superpave volumetric mixture design procedure. Yet, a number of studies have shown that the Superpave volumetric mixture design method alone is insufficient to ensure reliable mixture performance over a wide range of traffic and climatic conditions. As highway agencies begin the implementation of the AASHTO Mechanistic-Empirical Design Guide (MEPDG), they will be tasked with the development of local calibration factors specific to the materials, construction practices, loading regimes and environment of their region. The local calibration factors specific to the materials include the test of the dynamic modulus of asphalt mixtures. In fact, the dynamic modulus of asphalt mixtures is an important input parameter for pavement thickness design. Therefore, the objectives of this paper are to: 1) review the current status of Superpave simple performance tests for asphalt mixes; 2) measure the dynamic modulus of Superpave asphalt mixes, and; 3) compare with the predictive equations for the dynamic modulus to establish a correlation. The dynamic modulus data will be used in the MEPDG design procedure for asphalt pavements.

Recently the research on Perpetual Pavement has been very popular, and the basis of the structure design method for the Perpetual Pavement is the theory of the HMA "Fatigue Limit". In this article, the laboratory study for the fatigue characteristics of LSM Base Mixture chooses the Four Point Beam Bending Test method with four kinds of strain level and two kinds of asphalt content, and the two kinds of data analysis methods which include the AASHTO T321 method and the reduced energy ratio method are used. Based on the analysis of the fatigue tests, the fatigue limit for the LSM Base Mixture on the lower strain level (70 ∼ 100με) is verified.

With the expansion of the West Development, the investment in western traffic infrastructure is increased; however, some important issues regarding road construction are thus gradually emerging. For instance, one of the problems is related to highway construction materials. There has been experimental research and highway engineering practice at Mao Wu Su Desert in inner Mongolia Autonomous Region. This paper briefly introduces the main physical and mechanical properties of wind-blown-sand, opens out the rule of its compacted density, proposes the approach for determining the standard density of wind-blown-sand, analyzes the construction procedures of compaction without water and the methods of its compacted density.

This paper presents a comprehensive review of recently developed micromechanical modeling approaches for asphalt mixture in pavement engineering by the authors. These approaches include the Micro-Frame Finite Element Network Model (FENM) and microstructure-based Continuum Finite Element Model (CFEM) for predicting micro-damage behavior and constitutive properties of asphalt mixtures. Both models consider the multi-phase and heterogeneous microstructure and aggregate-to-aggregate interaction of asphalt mixture. Both finite element modeling schemes and their advanced features were described and addressed. Based on these developed models, the virtual laboratory simulation was conducted to compare with the laboratory specimen test results. Simulation samples were generated from surface photographic data of actual laboratory specimens by using image processing. Model simulation results of the overall sample behavior and evolving micro-damage patterns compared favorably with experimental data collected on the test specimens.

FRP-OFBG is a smart sensor in civil engineering due to its advantages of corrosion resistance, high strength, fatigue resistance, electric magnetic resistance, small size, etc. The experiment of FRP-OFBG sensors was conducted to test and analyze the structure strain of asphalt pavement in a Beijing freeway. The result shows that vehicle loads do more damage to the middle of the surface course. Therefore, FRP-OFBG sensors have stable characteristics and could be widely used to measure structure strain of asphalt pavement.