Traffic and Transportation Studies (2008)

Transportation has played a closer role with national interest, global economy, societal progress, human civilization than before. Sustainable development of human society is also more and more important to people. China is one of the biggest developing countries and the supply and demand of transportation infrastructure become larger during a period. Huge supply demand and transport demand require that we must have to pay more attention on the development problems of transportation in a new mode.

Traffic control measures are essential for ensuring the unblocked and high efficient traffic organization in the cities during the events. Taking the traffic operation status in Beijing before and after the Forum on China-Africa Cooperation in 2006 as an example, through the SP (Stated Preference) survey, this paper investigates the changes of residents' travel habits and trip modes before and after traffic demand management (TDM) measures were taken. By comparing the changes of the public transit passenger volume, car passenger volume, road network flow and operation speed in Beijing; it examines the influences of the TDM measures on traffic operation. It provides experience and decision-making support for formulating and implementing the TDM measures during the Beijing Olympic Games.

In Japan, the number of traffic fatalities peaked in 1970 with 16,765 persons. Thanks to the introduction of various countermeasures, the number was reduced to 5,744 persons in 2007. However, the number of traffic accidents has been increasing since the late 1970s and a very slow decrease of traffic fatalities of the first person concerned due to `distracted driving' and `looking aside while driving' has been observed in recent years. This is also true for the numbers due to lsquo;failure to confirm safety factors' and `improper steering/braking'. Therefore, this study focuses on such human errors and attempts to evaluate the effects of a warning information system as a tool to reduce traffic accidents based on a social experiment in Hiroshima, Japan. The social experiment was conducted collaborated with central and local governments, private sectors and the citizens during the process of implementation. The effects of the warning system on driving behavior are evaluated and future deployment directions of ITS technologies are discussed.

In this paper, three technologies for real-time traffic data collection, namely automatic vehicle identification (AVI), global positioning system (GPS) and video image processing (VIP), are evaluated. Their performances on journey time estimation are compared in a case study in Hong Kong. Journey times on a selected path are estimated using dataset collected by each of these three technologies and different combination of these datasets. Observation survey is conducted during a morning period on the selected path to validate the journey time estimates. It was found that the combination of AVI and VIP data can be used to provide cost-effective solution for real-time journey time estimation in Hong Kong.

Signal timing and coordination involves sophisticated optimization models, algorithms, and the roadway infrastructure to support the operations of traffic signals. On the other hand, an optimized signal timing plan also needs fine tuning in the field in order to achieve the best system performance. Such a field implementation and fine tune task may involve dealing with many factors, such as local driving habits, that cannot be anticipated and addressed using scientific approaches. Therefore, traffic engineers often describe signal timing as a form of engineering art. An experienced signal engineer often applies many innovative techniques combining the knowledge and skills from both engineering principles and artistic minds, namely the tricks and tips. This paper illustrates various tricks and tips used by practical signal engineers using several case studies. Specifically, the cases to be demonstrated include: left-turn phasing sequence, pedestrian handling, dealing with long arterials, and strategies for controlling closely-spaced signals. Applying the tricks and tips illustrated in this paper can provide quick fixes to some common operational problems without the need of significant capital investments.

This study is an attempt to explain the inelastic behavior of automobile drivers in response to road pricing with respect to the endowment effect, mental accounting and sunk cost. The results drawn from experiments suggests that the effectiveness of road pricing in achieving a desired optimal level of traffic depends on setting charges which incorporate the inelastic nature of demand and the high value drivers place on the loss of travel time as a result on traffic congestion. However, this must be complemented by a comprehensive and efficient public transport network, high parking charges within the CBD and environmental awareness on the social costs of traffic congestion.

The potential for transport to make a positive contribution to rural communities is significant. Both community-based and public transport services provide significant and essential lifelines to the communities and individuals served. The period since bus deregulation in Great Britain has led to a more widespread application of community and Demand Responsive Transport (DRT) services in locations where traditional bus services face tough commercial financial decisions. The ability to access work has a significant impact in the lives of all who wish to work. Rural communities place considerable emphasis on the ability to access opportunity and are likely to face significant challenges where transport availability changes or is not provided. A number of schemes have emerged specifically focused on the development of improved transport to work, which may generically be labelled as `access to employment' schemes. Typically these schemes rely on external funding from non-traditional transport sources and occupy a policy and service delivery area between economic development, social inclusion and transport. This in turn provides challenges when subjected to traditional evaluation methodologies and as a result, the survival and expansion of schemes, many of which prove highly successful in achieving their social and economic goals, may fall between relying on goodwill of diverse funding providers and remaining outwith the traditional `transport' schemes and their sources funding. This paper provides an alternative evaluation methodology for such `access to employment' schemes. The paper is structured as follows. The first section introduces the concept of rural access gain and considers existing contributions from the literature. The main body of the paper analyses Transport to Employment (T2E), a practical example of an access to work scheme operating in Highland Scotland to illustrate the wider social community benefits derived. This is made possible by use of an appropriate evaluation methodology derived from Social Return on Investment (SROI).

Fast urban mechanization on the one hand facilitates the urban development, and on the other hand, brings along a series of traffic problems. This paper takes Beijing as the background to analyze the mechanization trend of the urban transportation and indicate that car traffic is the main force driving the course of urban mechanization, as well as calculate the relationship between urban motor vehicle ownership and GDP. On the basis of taking into account the factors including socio-economy, traffic demand, traffic supply, traffic operation condition, transport policies, etc. in a systematical way, this paper analyzes the causal relationship among these factors and builds a System Dynamics (SD) model for adjustment of urban transportation structure. Based on this, it makes the simulation analysis on the urban transportation condition under different travel characteristics and the corresponding mechanized transportation structure, and considers it especially important to change the travel behavior characteristics of residents for improving the urban transportation condition, which provides the instrumentality of quantitative analysis for the optimization of urban transportation structure.

To properly reflect the interdependency mechanism between transport networks and trip-making behavior, an integrated travel demand model with feedback mechanism is established for Beijing, a typical developing mega-city. Compared with the conventional sequentially estimated four-step model, it is empirically confirmed that introduction of the feedback mechanism has greatly improved the model estimation accuracy. Moreover, the simulation results suggest that development of transit-oriented urban form with proper control of car ownership and increasing public transit lines would be a promising scenario to realize environmentally sustainable urban growth for Beijing.

The movement of people and goods increases significantly due to the rapid economic growth. However, too much traffic on a given traffic infrastructure negatively influences the natural resources, the environment, and the urban image. As developing countries have begun to increase their economic activities, the level of service on the already congested road networks starts to deteriorate. In addition, investments have been concentrated on new road facilities, and not on creating attractive public transport systems. A transportation master plan for the four million city of Alexandria is recently developed by the author. Its main objective is not only to fulfill the future travel demand, but also to generate new mobility on a sustainable way. The new mobility applications are clean, integrated, and smart. The purpose of this paper is to present the philosophy and main features of the master plan which contains three strategies: (a) reducing travel demand through the integration of land use and transportation planning together with the economic regional development, (b) modal shift from less to more environmental friendly transport modes, and (c) improving road system and simultaneously freedom and safety of pedestrians. The paper illustrates also a procedure to evaluate the sustainability of different scenarios, based on technical, economical, environmental, and social indicators. The evaluation confirms the sustainability of the master plan and its efficiency towards new mobility.

Each mode in the modern transport system owns its reasonable utilization in distance-axis determined by the user's burden in travel and the relevant intrinsic properties. The degree of person's burden in travel is not always the linear changes to the duration of time, and it is possible to become fast growing with the increment of time consumption. In this paper, an evaluation criterion for investigating mode's reasonable utilization is elaborated under the analysis of mode's transport service, and the construction of parametric model to express willingness-to-pay for saving time, using the transport service charge as defined with the traveling cost and time consumption. It is possible to calculate mode's reasonable utilization corresponding to distance comparatively, according to the method proposed.

Trip characteristics of urban residents are closely related to the traffic structure, and the trip characteristics are of important reference significance to the optimization of traffic structure and the alleviation of traffic congestion. Taking typical large cities in China and abroad like London, New York, Shanghai and Guangzhou as study objects and based on the comparison between the socio-economic development and the transportation infrastructure construction, this paper analyzes the trip characteristics of Beijing urban residents, including the trip rate, trip purposes, trip distances and the distribution of trip time, etc. In addition, the paper also comparatively analyzes the all-day traffic structures of typical large cities, the commuting trip structure as well as the traffic structure into the city center at morning peak hour. Through the research on the trip characteristics and the traffic structure differences, it is concluded in the paper that the unreasonable urban traffic structures is the important reason of the low operating efficiency and service level of the urban traffic system in Beijing, and to effectively alleviate the traffic congestion situation in Beijing, measures to optimize the traffic structure must be taken.

To enhance the quality of transportation planning and policy making, it is necessary to properly deal with the nonresponses in transport surveys, irrespective of developed and developing countries. This paper attempts to impute item nonresponses in person-trip (PT) survey data collected in a developing city (i.e., Jabodetabek Metropolitan Area, Indonesia) based on expectation maximization (EM) imputation method. As a case study, an aggregate multinomial logit model is used to represent travel mode choice at zonal level. It shows that even in case of low missing rate, the issues of item nonresponses could result in serious biased model estimation and consequently may lead to wrong policy decisions.

This paper examines the characteristics of choice behavior of urban rail users in the Tokyo Metropolitan Area and proposes the heuristic rules of generating the individual's choice-set by eliminating the options by his/her attributes. Then, we apply empirically the proposed rules to the simultaneous choice analysis of access travel mode, origin rail station and rail route with the Multinomial Logit models. The results show that the choice-set generation rule by eliminating by origin rail station and total travel time has the best fitness in the parameter estimation.

In 2006–2007, we conducted a so-called social experiment. A bus to transport commuters working in the Hanamoto Industrial Park had been operated between the Park and the nearest railway station. In terms of the result of the social experiment, the bus sharing service should be no charge for the employees as we did, and a council having the function of the adjustment as the third party should be charging the operation for a smooth management. Furthermore, the commuter bus sharing may be extended for the regional public transportation system.

While aggregate trip generation models are widely utilized in China, they are incapable of representing the travel decisions made by individuals/households, nor providing the temporal & spatial characteristics of activities and the trips they generate. This paper explores a discrete activity-based trip generation model by multinomial logit method. By taking trip chains which included in activity patterns as the analysis units, the coherent connections and constraints among multiple activities and trips can be reflected. In addition, the model contains individual/household socio-demographics and other policy-sensitive explanatory variables. The utility function estimated by the model can be applied in a straightforward way to obtain trip generation by aggregating the individual's choice probability.

The paper examines commuting behavior from employment sub-centers to residences in a metropolitan region. Traffic analysis zones are arranged in order of employment density using a rank-size distribution to identify discrete clusters of employment nodes. For each employment zone an employment location specific preference function for the journey from work to home is estimated from travel data. This allows the spatial extent of each employment center labor market to be determined. The mean trip length for the commute home from each employment center is explained by the parameters of the quadratic function that best fits the preference function. Results are presented using data for 1972, 1983 and 1994 for the city of Sapporo, Japan. Growth in population and employment with a poly centric employment formation in the suburbs has led to an increase in the region's mean trip length. A multivariate model estimates change over time.

The paper describes the conceptual development of a Prototype household based daily activity schedule model designed as a multi-agent simulation system with a household kernel agent. The paper presents a behavioral agent architecture that is used to reproduce the daily activity scheduling behavior of individuals as well as the household. The proposed architecture is thought to improve current individual based scheduling models by explicitly representing a household interaction mechanism in the process of daily activity scheduling. The model features interactive household agents. The schedule of the household members within the household are generated simultaneously to allow for the interaction between members that normally occurs within a household. The key way members interact in the current conceptualization is through household kernel agent. The household kernel agent is responsible for coordinating schedules of members to determine feasible allocation of household level activities among the person level schedule. Furthermore, the household agent is responsible for generating a set of joint activity episodes, in which more than one person in the household take part in an activity. In addition, the household agent handles conflicts that arise due to overlaps between competing activities at the person schedule, by representing a household conflict resolve mechanism. The household conflict resolve is intended to take the previously person scheduled activities and determines possible re-allocation to other individuals in the household.

Basing on single trip, the traditional travel demand analysis approaches such as four-stage method is inadequate to depict the activity sequence and difficult to reflect individual, family factors which influence to travel behavior. Its limiting has already been subjected to a lot of queries. To a commuter, work is the most important activity, so according to the commuter travel's chaining complexion, this paper analyzes activity chain patterns. By considering personal socioeconomic characteristics, household socioeconomic characteristics, family member's interactions and temporal characteristics, this paper presents an activity-chaining choice model, employing the discrete choice theory, for the analysis of commuter travel behavior. At last, an empirical analysis is adopted to specify and estimate commuter travel behavior using the data from Beijing Household Travel Survey 2005 (BHTS, 2005).

The intent of this paper is to demonstrate the heavy vehicle percentage is not a necessary factor for predicting highway work zone capacity. First, based on the analysis of a multiple regression model in previous study, an improved model introduced the concept of passenger car equivalent (PCE) and defined the effect index (EI) for evaluating the importance of different factor affecting the work zone capacity. The smaller EI of heavy vehicle percentage indicated that the heavy vehicle percentage was not the key factor when estimating the work zone capacity. Second, this paper also ran simulations to compare the travel time when the passenger car equivalent volume remained in the same. The results showed only 5% of the difference in the travel time varied with the heavy vehicle percentages. At last, a new model without the input of heavy vehicle percentage was further developed. Its performance had been proven to be better than that recommended in highway capacity manual (HCM).

In order to establish a favorable recycle relation between regional highway network and road transportation industry, we need process coordination to suit local conditions, and optimize disposition of economical resources. The authors use Data Envelopment Analysis (DEA) to estimate the relative efficiency of road transportation industry in our country. The results generated from the DEA model reflect whether the DMUs are efficient both on scale and on technique. And the DMUs that are efficient comprise the frontier and those are not are ranked according to how far they are from their best practice counterpart on the frontier. Then we could adjust the inputs indexes of the inefficient DMUs to achieve the efficiency of them.

How can traffic congestion in urban areas be relieved? The most traditional approach of simply adding more physical capacity is not always a realistic solution due to financial, environmental, social, political, physical roadway space or other constraints. However, enhancing the efficiency of the existing system can still make improvements to a certain degree depending on how efficient the existing system is. Often roadway congestion is not caused by the roadway segment where congestion is actually experienced, rather it is caused by bottlenecks downstream of that segment. In such situations, widening congested roadway segment serves only the purpose of storing more vehicles. Traffic operational improvements at the locations where the bottleneck exists may help reducing congestion by enhancing flow of traffic. This paper presents a case study (simulation model) that shows how freeway to freeway HOT lane connection through direct flyover ramps bring about more benefits compared to widening segments of a congested roadway by adding more than 25 lane miles. This simulation case study indicated that the widening option would reduce travel time by 15% whereas flyover ramps would provide 30% reduction in travel time along 15-mile segment of the corridor. The widening and flyover options increase throughput by 7% and 16%, respectively. This paper documents simulation model parameters, assumptions, and findings.

In this paper, authors make an attempt to find out the structure of freight transport charge through the analysis of current market situations under the economic deregulation. Firstly, the historical transition of truckage system of Japan is described by and large. Secondly relevant effect factors for deciding freight rate are systematically analyzed according to actual rate concerning main shippers. Furthermore some models to express compositive mechanism of truckload's freight rate based on mileage system are constructed. Finally the relevant suitability of model is discussed and the influence degree of each constituent factor is derived.

There are many airports in Japan. A couple of them are big ones such as Haneda (Tokyo), Itami and Kansai (Osaka) that are located in or around big cities. Other airports, many of them that are local airports are in middle or small scale cities. In case of connecting to the airport in big city, they are able to have large demand of trip. But in case of connecting to one in small cities, they probably are not expected to have large demand. In addition, the presence of high speed rail accelerates the reduction of demand for flight. In this paper, some policies for the promotion of using local airport are examined, especially trip from local airport to another local one. We already had proposed the long trip model for business travelers in which people decides their depart time and mode. We used it to examine the policies and situations such as frequency, fare, access time to the airport.

Integrated fleet dispatching, which means solving both "airline fleet assignment (AFA)" and "tail number assignment (TNA)" problems together, is a trend in airline industry. Based on domestic airline operational characteristics, an implementation technique to solve integrated airline fleet dispatching problems is presented in this paper. Detailed study contents include: (1) Proposing an "airplane-flight pairing assignment cost" guideline to evaluate the fleet dispatching scheme quality; (2) Developing a "flight pairing connecting network model" to describe integrated airline fleet dispatching problems; and (3) Constructing an heuristic algorithm based on a simulated annealing algorithm. Simulated tests proved the feasibility of the techniques. This research can help domestic airline improve operational control management.

Ports constructed several decades ago are unable to accommodate the rapid economic growth and urbanization in China. Most of the ports have been built within the cities. As a result, it is difficult for the ports to expand due to constraints of space, and many Chinese seaport cities have to completely or partly move the ports out of the cities. The relocation of the ports will certainly change the urban land use patterns, especially those around the old and new port areas. This study proposes an industrial location model, which simulates the location behaviors of the port-related industries in terms of transport accessibility, land price, aggregated degree of similar and relevant companies, and abundance of service facilities. A case study is illustrated for application of the model using the Dalian Port as an example.

A forewarning model of freight rate was established based on support vector machine (SVM) and its algorithm was developed in order to analyze and forecast the alarm of freight rate fluctuation in shipping market. In accordance with shipping experts' knowledge and experiences, the actual alarm degrees of freight rate within the sample interval of shipping market were determined by CCBFI, CCFI, and BFI, which were selected as alarm criteria. The classification hyperplanes and forecasting intervals of freight rate alarm degree were obtained from SVM learning and MATLAB programming, based on sample data trained. And then the interpolation and extrapolation tests were carried on. The results of tests show that this methodology has a very good serviceability regarding to forewarning of freight rate in shipping market.

This paper presents the results of research into the evaluation of alternative scenarios for freight terminal location in an urban area in Australia. The research combines the use of a strategic transport model for overall freight demand forecasting, with cost assessment of the specific impacts of locating future terminals in selected areas. Outputs of the model were used to evaluate the impacts of urban freight terminal location decisions on all traffic in the road network. The work includes freight trip generation, using strategic transport modelling software (VISUM) to forecast future patterns of urban freight flows, calibration of the model, and option testing using a case-study in South East Queensland to predict the transport cost impacts of several locations for intermodal terminals.

There have been several studies dedicated to the climate change impacts on transportation in Canada since 2003 when the first Canadian national workshop on the impacts of climate change on transportation was held. This paper is an extension and continuation of the previous study — modeling potential changes in demand for freight transportation in Atlantic Canada due to climate change impacts — completed by the author in 2005. The current paper looks into overall aggregate impacts of climate changes on Atlantic Canada's transportation system. First, the question of whether or not Atlantic Canada is subject to climate change is addressed. Second, climate change impacts in Atlantic Canada are evaluated in monetary terms. Finally, major consequences of these impacts for the volume of ground freight transportation in Atlantic Canada are presented on the basis of computer simulations.

International trade is the backbone of our modern, commercial world, as producers in various nations try to profit from an expanded market, rather than be limited to selling within their own borders. There are many reasons that trade across national borders occurs, including lower production costs in one region versus another, specialized industries, lack or surplus of natural resources and consumer tastes. In this paper, international trade distribution is analyzed using the Asian multimodal network. This network consists of 31 countries and for the purpose of this study trade is assumed to be distributed between the capitals of the countries. The study concentrates on the Gravity model of transportation planning, the Linear Programming and the Empirical-Gravity model of Trade. Commodity class 3 according the SITC commodity classification as considered. Two observed matrices are used based on the countries' export/import trade information. Variables used are: Population, Area, gross Domestic Product (GDP) and Land Locked for each country, also the shortest distance and the minimum cost between capital pairs in three sub-networks defined and finally the direct air distance between capitals. After calibrating the models, these models are analyzed and compared according to the assessment criteria used in this study. The results indicate how well each model explains the trade distribution of this commodity in the study networks. From the results it was concluded that based on the data gathered for export between the countries, gravity model of transportation using distance in the multimodal network as it's impedance factor, best represented the trade. Based on the import data, however, the best model is the gravity model using the cost in the HS network, a sub-network allowing trade to be distributed according with Sea or the Asian Highway network.

Urban public transport systems play a very important role in large cities, and the policy of public transportation is often considered in the urban transport planning and the development of traffic control measures. Based on a new type of discrete choice model, a stochastic transfer optimization model of public transport is presented. The travel time, the transfer waiting time, and the number of transfers are all addressed in the model. A parameter estimate method containing the Newton-Raphson algorithm to the stochastic transfer optimization model is proposed. The experiment on the data set collected from a recent survey in the city of Lanzhou, China, proves the correctness and the efficiency of our method.

Drivers' driving behaviors and psychological states not only affect traffic operation but also have direct impacts on road safety. This study aims at categorizing various aberrant driving behaviors and discovering their connections with drivers' features. Based on Manchester Driving Behavior Questionnaire, driving training experiences were taken into consideration, and a questionnaire was administrated to 135 drivers in Beijing. Principal component analysis defines five factors: errors, lapses, unintentional violations, deliberate violations and emotional behaviors, which fit the presumed factor structure. Through ANOVA and multivariate regression analysis, the foremost influential factor of driving behaviors is found to be drivers' self-assessment and attitudes, such as drivers' evaluation of their emotionality and their attitudes toward traffic regulations. The second influential factor is driving training experiences including training site and time span, which was not involved in the studies before. Other factors, such as gender and age, are not found to be quite influential on driving behaviors.

In vehicular traffic modeling, the effect of link capacity on travel times is generally specified through a delay function. In this paper the Generalized Regression Neural Network (GRNN) method that supports a dynamic network loading (DNL) model is utilized to model delays on an unsignalized highway node. The presented DNL model is constructed with a linear travel time function for link performances and an algorithm written with a set of rules considering the constraints of link dynamics, flow conservation, flow propagation, and boundary conditions. The GRNN method is utilized in the integrated model structure in order to provide a closer functional approximation to pre-defined flow-rate delay function, a conical delay function (CDF). Delays forming as a result of capacity constraint and flow conflicting at an unsignalised node are calculated with selected GRNN configuration after calibrating the neural network component with the CDF formulation. The output of the model structure, run solely with the CDF, is then compared to evaluate the performance of the model supported with GRNN relatively.

A stochastic, time-dependent (STD) network is the network in which the arc weights are random variables with the probability distribution function changing over time. If there is more than one attribute of concern in selecting an optimal path, then the networks are called multi-attribute stochastic, time-dependent (MSTD) networks. Based on the multi-attribute decision making about information entropy, an exact algorithm is proposed for obtaining synthetic optimal hyperpaths from all nodes to a specified destination in MSTD networks. Synthetic optimal hyperpaths consist of a set of path strategies that enable the traveler to select a direction to his destination at each node in response to knowledge of the arrival time. In the end, an illustrative example is given to clarify the algorithm.

When optimizing traffic management strategies of urban transportation networks, one-way streets configuration and signal setting problems are often dealt with separately, i.e., when considering one of them, the other is assumed to be fixed and given, or ignored. However, the interactions and interdependences between the above two aspects suggest that simply combination of individual optimal schemes is not necessarily the combined global optimal scheme. This paper does address the combined optimization problem of one-way streets configuration and signal setting taking account of route choice behaviors. One-way streets configuration and signal setting are described by binary integer and real-valued variables respectively. A mixed integer bilevel programming model is formulated to tackle the Stackelberg game of the decision process in which the upper level sub-problem aims to minimize the total travel time encountered by all drivers considering signal delays; while the lower one, a stochastic user equilibrium model, aims to describe route choice behaviors of users reacting to the given one-way streets configuration and signal setting scheme from the upper level. Then, a hybrid GA-MSA solution algorithm is proposed to solve this BLP model. Finally, a numerical experiment is included to demonstrate the application of the proposed model and algorithm.

To describe the evolution principle of vehicular queue in the congested traffic flow, the equivalent queue length model for a single-lane link and the average equivalent queue length model for a multi-lane link are built based on the two-fluid theory. By applying the calculous, the average equivalent queue length change rate models are deduced for single-lane and multi-lane links respectively. It is found that the change rate of equivalent queue length is relative to the traffic wave speed and they are identical at the special circumstance. Finally, the equivalent queue length change rate models are validated by using the simulation data from VISSIM. The results show that the equivalent and actual queue length change rates approach during the sampling interval and they more approach when the sampling interval is longer. When the traffic flow is in the congested state, the evolution speed of vehicular queue can be described quantitatively and simply by the equivalent queue length change rate model. The model provides the theoretical basis for adjusting the strategy of urban traffic control.

A new method to construct complex networks from chaos time series is proposed, which each phase space represented by a single node in the network. The method can be used to understand the dynamics of chaos time series (CTS) from the complex network's perspective. We find that different threshold values of status space distance correspond to different network topologies including star, scale-free, single-scale and broad-scale networks. Another finding is that, with the increase of threshold value, the CTS generate networks that exhibit small world features. Compared with pseudoperiodic time series, the chaos attractor may reveal a more heterogeneous structure. Significantly, We develop a unified evolving mechanism to generating different complex network by chaos prediction and adjusting threshold value. It is found that the chaos attractor is essential for the emergence of a common scale-free, single-scale and broad-scale network structures.

This paper proposes a robust transport network capacity planning model (RTNCP) with demand uncertainty. The stochastic demand is assumed to follow a normal distribution with travellers' route choice behaviour following Probit Stochastic User Equilibrium (SUE). The network reserve capacity is measured by potential increase in both mean and standard deviation of the base stochastic demand. The objective of the RTNCP is, thus, to optimise the link capacity expansion so as to maximize the weighted sum of mean and standard deviation perturbed demands without violating the link capacity and budget constraints. The paper applies the implicit programming method to solve the optimization problem. The sensitivity analysis approach is adopted to derive the derivative of the equilibrium path choice probability with respect to design variables. The proposed model and algorithm are then applied to a test network.

By analyzing the previous offset optimization models and algorithms for arterial control systems, the paper provides a new offset optimization model and a relevant algorithm based on satisfaction degree. At first, by utilizing the Bayes Dynamic Model and its forecast algorithm, we get the travel velocity of road section and its distribution parameters. Secondly, by analyzing the relationships between travel velocity and offset of arterial control systems, we obtain optimal control scheme on the basis of multi-attribute decision making methods about satisfaction degree. The parameters, such as travel time, delay and average queue length etc., are considered mainly in the process of decision making. Finally, an example is given to verify the validity of the model and the algorithm.

The great potential of natural and unnatural events in many countries like Iran along with the strategic role of transportation networks in a country's economic, disaster management in Iran's transportation network, especially in its capital, Tehran, has a great importance. Also transportation networks play an important role in various stages of response to disasters, such as evacuation, search and rescue, and reconstruction missions. Hence, special attention must be paid to transportation networks in any disaster management system. Reliability measures are critical in judging the performance of a transportation system and it is very important to evaluate the performance of the network after disaster under the most probable scenarios in planning stages before disaster. In this paper, the causes of degrading link capacities will be discussed and we will propose a new algorithm for computing the reliability of Tehran's transportation network during the occurrence of an earthquake. In other words, we will present an approach for optimizing disaster management of transportation networks. We will verify our claim using simulation by MATLAB. By using the proposed method to compute the reliability, acting in various stages of response to disasters (search, rescue...) by simulation of network's performance would be easier and more secure in planning stages before disaster.

Limited by the capacity of its own fleet of vehicles, a logistics distribution center cannot handle all the transportation job orders and have to outsource some to other local transportation companies. By analyzing different kinds of job orders received from the customers, an agent-based model is presented to describe the problem and a general model of vehicle capacity planning system (VCPS) is built to tackle the problem, which models the problem as a modified and more complicated vehicle routing problem with time window constraints (VRPTW). In the study case, a taboo search (TS) method is applied to find a solution for the problem. From the results, some new rules on how to assign jobs for outsourcing are derived, and it shows the new rules is better than the traditional existing rules currently adopted by the practitioners.

The Vehicle Routing Problem (VRP) with stochastic demands was discussed. In this kind of VRP, the number of vehicles to serve customers and the number of customers served by each vehicle were unfixed before performing an optimization. A tabu search algorithm was designed for this purpose. In the algorithm, a vehicle-customer structure concept was designed to simplify the neighborhood structure. In order to analyze the effectiveness of the tabu search algorithm, a genetic algorithm and a hybrid algorithm were designed. The computational result showed that the tabu search algorithm based on the vehicle-customer structure was more effective than two other algorithms for the Vehicle Routing Problem with stochastic demands.

Traffic flow on freeway is a complex stochastic nonlinear phenomenon, with many complex interactions between vehicles and random perturbations such as traffic jams, incident and delay phenomenon. The Cell Transmission Model (CTM) is one of the most widely used dynamic link models for simulating dynamic traffic network. Its popularity is due to its simple formulation and low computation requirement. In this paper we develop a stochastic cell transmission model (SCTM) to model the evolution of traffic flows on freeways taking into account various uncertainties. We model the transportation network as stochastic system with various supply uncertainties (random variables). The SCTM is formulated by using analytical probability theory and is formulated into a discrete time bilinear stochastic system. A set of probablistic switching conditions is proposed to evaluate the joint traffic density.

In this paper, the characteristics of motor and non-motor traffic and their interference in urban mixed traffic network are discussed. A new link resistance function is presented, in which the interference between motor and non-motor is taken into account. On this base, a combined model is proposed by using variational inequality method, in which the travelers' mode choice and route choice behaviors are considered simultaneously. Then a systematical optimization model for urban mixed traffic network is proposed by using bi-level programming. Finally the application of the model and its algorithm is illustrated with a numerical example.

The importance of finding a location for road freight hubs is discussed in this paper. By turning the transport unit cost of freight and the transport amount from zones into fuzzy parameters and taking the capacity of the hub constraint into consideration, a fuzzy chance constrained programming model focusing on freight hub-locating is put forward. Furthermore, a Genetic Algorithm is designed in which a penalty function is adopted to decrease the possibility of the appearance of infeasible. The optimal result is obtained by using the model and the algorithm, which conform to the existing situation of Gansu province.

For a traffic network with fixed demand of heterogeneous users in terms of their different values of time (VOT), the system performance can be measured either in time unit by the total system travel time (in short, system time), or in monetary unit by the total system travel cost (in short, system cost). Thus we have two different objectives for network optimization, i.e. to minimize system time, and to minimize system cost, which naturally gives rise to a bi-objective minimization problem. A Pareto optimum of this bi-objective optimization problem represents a bi-criteria system optimum for network optimization in the sense that, at each Pareto optimum, neither system time nor system cost can be further reduced without increasing the other one. We bound the system performance gap when optimized by the two different criteria. Specifically, we provide answers to the following questions: When system time is minimized, how far could the corresponding system cost deviate from its minimum value? Reversely, when system cost is minimized, how far could the corresponding system time deviate from its minimum value? More generally, how far can the system time and system cost at a given bi-criteria Pareto optimum deviate from their respective single-criterion based system optimum?

Advanced traveler information system (ATIS) have been put forward as possible solutions for reducing congestion of metropolitan cities. The traveler behavior model is the key point on research of traffic flow in ATIS. There are three kinds of ATIS market: the complete ATIS market, incomplete ATIS market and non-ATIS market. In different ATIS markets, we consider different two classes of drivers. A two-user Travelers Game Model was build and the equilibrium of such model was discussed. The solution of Bayesian equilibrium was studied in the incomplete ATIS market and non-ATIS market. In the complete ATIS market, Nash equilibrium is analyzed. In this paper, a two-user traveler game model was proposed under ATIS in a three-route road network. This paper compared expectation of total travel time under different ATIS market penetration. Then we found that more market penetration of ATIS didn't mean less total travel time, and whole expectation of travel time in network firstly went up and then went down while market penetration of ATIS was increasing. In the end, this paper presented several emerging research in the issue of travel game.

Providing better environment in bus/tram stops where passengers can wait for bus/tram comfortably is an important factor for reducing disutility of out-of-vehicle travel time by bus/tram and promoting public transport use in multi-modal transportation planning. In this context, possibility of engaging in a variety of activities while waiting for bus/tram could contribute to reducing disutility of waiting time. This paper investigated what kind of activities passengers were engaging in while waiting for the bus/tram at various bus/tram stops. Analysis of data obtained from on-site observation and questionnaire surveys revealed that more passengers were engaging in activities as waiting time increased and there was difference in activity engagement between ages. Irritation levels of waiting at bus/tram stops were affected by the length of waiting time, the use of benches, passengers' socioeconomic characteristics, and trip attributes. Usefulness of the bus departure time information system and problems in non-guarded tram stops were also discussed.

This paper presents a combination transit scheduling scheme which some vehicles provide an all-stop service and the other vehicles are allowed to skip some stops as an express service. The stops serviced by express vehicles are determined by the unbalance coefficient of passenger demands on a given public bus line. The underlying scheduling model with express strategy based on the congestion effect was formulated as a nonlinear programming problem. The objective is to minimize the total of passenger waiting times, passenger in-vehicle times and vehicle running times. A heuristic procedure which is based on genetic algorithm was used to solve the model. Finally, the proposed model and algorithm were successfully tested with the help of a real-world case.

With the latest development in traffic demand management, the demand for traffic and transportation analysis based on microsimulation is increasing. This study investigates an application of traffic microsimulation with adaptive signals for bus priority option testing. The application was undertaken by baseplus Ltd for Christchurch City Council (CCC) and entitled "Bus Priority Corridor Model of Papanui Road". The purpose of the bus priority option tests was to estimate the effect and benefit of the option designs for bus priority during peak traffic periods. The study was undertaken to measure the improved travel times for public transport as a result of the proposed bus lanes in congested traffic conditions. Various option designs were proposed and were modelled, analysed and evaluated using microsimulation. The results were studied and compared on model stability evaluation, turn counts and journey times, time and distance (TD) analysis for buses and vehicles, bus reliability, etc. The impacts of the proposals are predominantly realised at signalised intersections, hence adoptive signal control has been incorporated into the model to ensure confidence in the modelling results and outcomes.

With the increasing attention to the funding issues on transit operation, a bus stop spacing model is generated with the aim at minimizing the operation cost without impact on transit accessibility. Two cost functions are considered in the model including passenger access cost and in-vehicle passenger stopping cost aiming at minimizing total cost. A bus route in Portland, Oregon, USA is examined as an example using Archived Bus Dispatch System (BDS) data provided by TriMet, the regional transit provider for the Portland, Oregon metropolitan area. Based on the optimization model, the theoretical optimized bus stop spacing is 930 feet comparing to the current value 802 feet.

Recent developments in public transportation in China are aiming to increase transit efficiency and particularly toward minimizing bus delays with the goal of relieving congestion in most cities. Understanding the factors that impact bus velocity (and hence travel time) has important implications for improving China's public transit facility design features relative to public transit efficiency. This paper describes a simulation-based evaluation model designed to support a quantitative exploration of the factors influencing bus travel efficiency. In order to make the results more reasonable and relevant to China's urban traffic characteristics, the simulation is based on measurements from real-world traffic conditions. The model's capabilities are demonstrated using an orthogonal experimental design (OED) method. Nine independent variables and their attributes were defined: presence of a bus lane, bus stop type, bus stop location, non-bus volume, bus volume, right turn percent, bus dwell time, presence of bus berths, and green ratio. Three evaluation indices were used: bus velocity, non-bus velocity, and all-vehicle velocity. An illustrative case study also demonstrates that the OED can be a useful tool in the traffic and transportation field for further research.

There are two common objectives when performing signal timing optimization and deriving coordinated signal timing plans: maximizing bandwidth and/or minimizing delay. It is hypothesized that signal timing solutions would depend on the Origin-Destination (OD) traffic flow patterns. The primary objective of this paper is to investigate how signal system's performance changes under various OD flows and coordinated signal timing plans. A case study was conducted using data collected from a signalized arterial in Reno, Nevada to demonstrate the investigation. VISSIM traffic simulation was used to compare the performance of two signal timing plans under three different OD patterns. The two signal timing plans included a bandwidth-based solution from PASSER II and a delay-based solution from Synchro. The three OD patterns were derived based on the same set of turning volumes. Results from the simulation indicated that different OD patterns produced different performance measures under the same signal timing. It was also found that bandwidth-based signal timing outperformed delay-based signal timing in all the cases analyzed, especially when the arterial traffic was dominant.

Traffic volume data is one of most important information for decision-makings related to planning, design, management, operation, and control of transportation system. Often, traffic count data are not available for a significant portion of highway network because it would be prohibitive to cover all roads with traditional traffic-counter based monitoring system, particularly for low-class roads in rural areas. In cases where traffic volumes are needed but unavailable, travel demand models (TDMs) can be used to estimate such information. This study implements TDMs for two regions in the province of New Brunswick, Canada. Study results show that TDMs can generate reasonable traffic estimates for low-class roads. The methodology proposed in this study features with relatively low implementation cost and resulting traffic estimates can general meet data needs of low-class roads.

A microscopic simulation model for pedestrian dynamics was developed. The model was made up of self-driven force, repulsive force, and pre-avoid force, which were virtual forces reflecting pedestrian's psychological characteristics and instinctive consciousness. The model was validated by both real data and simulation which indicated that the model was suitable for describing pedestrian's social characteristics under normal conditions.

In order to estimate passenger traffic efficiency under different mass transit railway (MTR) station design and operation scenarios, a microscopic simulation model of passenger mustering and evacuation was developed. Passenger flow was considered as an aggregation of a large amount of entities with specific properties and behaviors. Each entity's behavior was classified into three levels with five steps as follows: path finding, move, collision avoidance, node selection, and probabilistic optimization. Models were set up at each level respectively. By simulation, useful indexes can be obtained such as passenger delay, infrastructure level of service distribution, space, and temporal diffusing of bottlenecks. Besides, interesting self-organization phenomena was also found. Examples from the Beijing MTR transfer stations were provided to validate the application of the proposed model. It was concluded that the model was effective at simulating passenger crowd systems.

To cope with origin-destination (OD) matrix estimation, numerous approaches have been developed. However, very few techniques have ever been proposed for estimating OD matrix for Urban Rail Transit (URT). The paper discusses the problem of how to estimate URT OD matrix based on OD survey data, such as origin station, boarding time, transfer station and destination station. One major concern is how to calculate the time of transfer and alighting through the train schedule; the other is how to estimate the OD matrix based on the Fratar model. Case study is conducted to test the proposed approach using the actual survey data in one city. The results demonstrate that using the Fratar model to solve the problem of OD matrix estimation is practicable, and the credibility reaches above 95%.

Braess' paradox is well-known and examined. However, an emission paradox, an analogue to Braess' paradox for vehicular emissions, is not. Without considering the emission paradox, the road network improvement that mitigates congestion may increase harmful vehicular emissions. In this paper, we analytically examine the occurrence of the emission paradox and the simultaneous occurrence of the Braess and emission paradoxes in the classical Braess' network. We ascertain that the occurrence of the emission paradox depends on the demand for travel, the parameters of link performance functions as well as link emission factors. We also find that the Braess and emission paradoxes do not always occur at the same time, and that the emission paradox is more likely to occur than the Braess paradox in some networks. More importantly, we discover that under some conditions of the parameters of link performance functions, the emission paradox does occur but Braess' paradox does not. This implies that road network design for mitigating congestion alone may not be able to avoid the increase in vehicular emissions. A more comprehensive view for road network design is necessary to avoid the occurrence of both the Braess and emission paradoxes.

We discussed the role of medians at signalized intersections for utilizing as pedestrian refuge island from the viewpoint of users' consciousness and behaviors. Especially, we focused on the crank-type crosswalk installed with or without a two-step crossing operation. As a result, it was revealed that the crank-type crosswalk with two-step crossing operation can have an effect on the reducing risky behaviors after flashing green signal under the adequate signal phase setting.

Current service measures of unsignalized intersection level of service (LOS) in the Highway Capacity Manual (HCM) do not include safety measure; thus, the LOS cannot reflect intersection safety situations. In order to make the LOS of unsignalized intersections fully reflecting traffic efficiency and safety, the concept of safety level of service (SLOS) was proposed. The models for SLOS were developed, and the current LOS service measure (delay) and the studied SLOS evaluation index (risk index) were combined to form an improved service measure (delay and risk index) for unsignalized intersections. According to the original LOS criteria and distribution of risk index values of SLOS, the improved LOS criteria were defined. The application results show the improved LOS criteria can thoroughly reflect the operational and safety performance of unsignalized intersections.

Behaviors of car following at signalized intersections are different to those on roads, especially during the start part of green time. As green indication starting, vehicles in the linked approach begins to move and often emerges a particular course observed as that a closely-spaced platoon of moving vehicles comes into being and then turns to disperse. This course usually takes place for the interrupted flows, especially for the resting queues, during the early period of their re-moving. This paper divides movement of each vehicle in this course into four stages: initially accelerating from rest, shortly after which reducing acceleration rate to join a moving platoon, then increasing acceleration rate to disperse from the platoon and eventually stepping into a free flow. It develops a mathematic model to describe the four-stage movement. It also designs a performance measure (intersection passing time) and carries out some case studies based on field data in Beijing city to validate the model. It reveals that the proposed model is applicable to model vehicles movement during the start part of green time. It is found by the proposed model that drivers' decisions at the second stage have much effect on total delay of vehicles in the middle or rear of a queue.

Protected and protected/permitted are two major left-turn control types at signalized intersections. Selection of one control over the other usually involves comparing results in the aspect of efficiency versus safety. This paper presents an economic analysis approach to assessing protected/permitted left-turn control versus protected only left-turn control. The approach involves a benefit-cost analysis of utilizing simulation tools and statistical methods to evaluate the change of left-turn control type from protected only to protected/permitted at signalized intersections. A case study was conducted to demonstrate the application of the approach. Based on the analysis results of the case study, it shows that by implementing protected/permitted left-turn control instead of protected only, the benefit from improved efficiency exceeds the cost from increased accidents, which provides justifications of the change of the left-turn control type at the study intersection.

In this paper, we study a two-lane traffic system consisting of a mixture of cars and taxies. The taxies occasionally stop to pick up or drop off passengers. The empty taxi rate, getting on rate (defined as average number of passengers that get on taxi in unit time), fundamental diagram, passenger carry capability, and lane-changing frequency are investigated under different sets of parameters. Some insights are obtained and explained. For example, (i) the flow rate still decreases even if the taxies stop less frequently; (ii) getting on rate does not monotonically increase with the pick-up rate. The diagram of the maximum value of getting on rate is also presented, so that an optimum taxi number could be suggested. We expect our works could be useful for taxi administration and traffic management.

From the business viewpoint, the railway timetable is a list of the products presented by the railway transportation operators to the customers, specifying the schedules of all the train services on a railway line or network. In order to evaluate the quality of the train service schedules, a number of indices are proposed in this paper. These indices primarily take the passengers' needs, such as waiting time, transfer time and transport capacity into consideration. Delay rate is usually used in post-evaluation. In this study, we propose to give an evaluation on the probability that the scheduled train services are likely to be delayed and the recovery ability of the timetable after delay has occurred. The evaluation identifies the possible problems in the services, such as excessive waiting time, non-seamless transfer, and high possibility of delay. This paper also discusses the improvement of these problems through certain adjustments on the timetable. The indices for evaluation and the adjustment method on timetable are then applied to a case study on the Hu-Ning-Hang railway in China, followed by the discussions of the merits of the proposed indices for timetable evaluation and possible improvement.

In this paper, we describe the railway crew scheduling problem as a set covering model. Due to the large size of the problem and its intrinsic complexity, we propose an approach that starts with a decomposition phase to assign all trips to depots and gets a set of subproblems. A column generation algorithm is embed in genetic algorithm to get the lower bounds of the subproblems. In the second phase, we solve the linear programming relaxation of the models using a column generation scheme. Then we use a branch-and-bound technique to get satisfied integer solutions. The performance of this appraoch is compared with central solution by an instance. And our column geration based two-phase approach shows an improvement with respect to computation time.

Making use of arrival and departure station tracks is a key problem afflicting passenger transportation at railway stations. In this paper, a scheduling model of utilization scheme is created for railway station tracks. It is set up by analyzing the characteristics of the tracks, features of train occupation time span and other factors that have an effect on the utilization scheme. Since creating a utilization schema for railway passenger station tracks has proven to be a difficult problem, a heuristic algorithm is proposed to create a satisfactory solution. By using the model and algorithm presented in this paper, a solution is obtained that enhances the management technology of transportation and improves the level of automatization for train operations. Studies based on the actual data of a certain railway passenger station combined with the optimization model are used to create a utilization scheme for station tracks. Results from this study imply that optimization occurs.

Railway transportation plays an important role in China's economic development. Similar to the case of economic development, the railway industry involves cycle fluctuation. The paper proposes a spectral theory-based approach to analyzing the characteristics of railway transportation cycle fluctuation. The case studies on identification and determination of the four transportation indicators, including railway freight volume, freight turnover volume, passenger volume and passenger turnover volume, indicate that there is a medium wave of 7–9 years and a short wave of about 3 years during the development of railway transportation.

Modeling trains to run in different signalling system environments is one of the key topics in SAREE (Simulation Analysis system of Railway Efficiency and Economics in high-speed railway passenger dedicated line). On the basis of analyzing relationship between train running and the signalling system, we created an agent-based train running simulation model. We also discuss its structure, related formalization definitions and its decision-making mechanism. The architecture and functionality of the simulation system SAREE are introduced and one case study is also presented. The simulation result shows that our model can meet the train running simulation requirements of PDLs. At the end of the study, we present conclusions and upcoming research.

An integrated model based on the system cloud grey model and Markov chain was established to forecast the change of land type along urban rail transit. First, the system cloud grey model was used to get the dynamic baseline for the area of every land type along the rail transit from 1997 to 2015. Second, a Markov chain was applied to achieve the state-transfer probability matrix, by which the forecasting result based on the system cloud grey model was modified. This integrated model takes randomness of land type changes into account; moreover, the model is available when statistics are scarce. Finally, the Rail Transit Line 1 in Nanjing was taken as an example to illustrate the application of the model. The forecasting result shows that the model is practicable.

This paper discusses the service robustness of trains in scheduled railway timetables, and it also establishes the verification relations between Train Movement Calculation and railway timetables evaluation. A Train Interval Control model with Pure Moving Block Signaling system (P-MBS) is developed and realistic traction characteristics of trains are taken into account. The model can get time intervals between two consecutive trains at block sections and buffer times is used to analysis the robustness, moreover the robustness is calculated according to the extra cost caused by delays. We select a 335.3 kilometers railway dedicated passenger line and four trains to simulate, and the results show that it is an acceptable approach to evaluate the service robustness of trains.

Railway accidents are often caused by multiple factors. Therefore, it is necessary to accurately analyze the factors affecting railway traffic safety. We used the Rough Set Theory, which is often used to deal with the uncertain and inaccurate mathematic puzzles for solving this problem. Firstly, the main factors affecting the train operation safety are discovered. Secondly, the factors are assorted and each of them is assigned a value respectively by their characteristics then train operation accidents are ranked into different classes by their damage to the railway. Based on the process described above, a decision-making table for analyzing the causes of the train operation accidents is established. Then the decision-making table is calculated using the relative importance degree of the Rough Set Theory to show each factors influence on the train operation safety. The conclusion could be used to offer effective measures for preventing railway accidents and relaying train accident information to decision makers. Finally, the calculating method and steps are given via a case study, and then research directions in the future are put forward.

This thesis aims to probe into optimal control approaches for freight train by giving priority to the objective of minimizing energy consumption, which is also expected to design the algorithm for optimal real-time control of freight train based on the handle control of the locomotive, and develop a set of guiding devices applicable to optimal control of train under different signal systems and railway conditions. The guiding devices is capable of conducting dynamic collection of train running information to proceed with the online design of guiding proposal for optimal control applicable to the current running environment. According to the results of test carried out at the section between Changanji-Dagudian under the governance of Shanghai Railway Administration, the guiding devices can reduce the energy consumption and delays while ensuring the safe and smooth running.

To provide effective support for the functioning of the transportation channel, the overall supervisory and control systems architecture of railway transportation systems must be capable of linking or coordinating the information systems of the individual parties into a cohesive whole. After analyzing the features of supervisory and control systems of railway transportation system, issues of data noise were raised regarding the information revising algorithm for extracting appropriate data from massive and heterogeneous data sources. Bayesian Networks (BN) provides a robust probabilistic method of reasoning under uncertainty. In order to eliminate the noise, a new method is presented for extracting appropriate data from control data sources, which is based on the Bayes decision-making theory. Prior specification and stochastic search were two important components of this approach. First, Bayesian networks and the Monte Carlo method were introduced briefly. Secondly, the combination of prior probability and data samples induced a posterior-distribution. Then, Bayesian networks were used to investigate the performance of Gibbs sampling algorithms for inference with WinBugs. Finally, the experimental results were presented and discussed.

At signalized intersections, turning vehicles often use the same share lane together with the through traffic. For example, at small and medium intersections, there is often only a single lane approach which is used both by left-turn and through movement. Obviously, in case of those single-share lanes, only a permitted control for the left-turn movement is applicable. Since a permitted left-turn movement has to give way to the opposing through movement, it has to wait if necessary and thus impedes the through movement in the same direction. In the reality, if the left-turn movement is permitted controlled, the through movement at the same approach can be totally blockaded by waiting turning vehicles during the green time. Thus, the green time for the share lane cannot be efficiently utilised and the lane capacity under consideration cannot be fully received. In the existing capacity manuals for traffic quality assessment, there are not yet adequate procedures for taking into account that effect of blockage. In the current US Highway Capacity Manuel there are only empirical regression functions for the effect of blockage based on measurements and simulation studies. Unfortunately, using this regression functions, some important margin conditions are not satisfied. As a result, the capacity of the share lane is calculated inaccurately under particular conditions. In this paper, a mathematical model is presented for an exact calculation of the blockage probability caused by permitted turning vehicles and for the estimation of the capacity of single-share lanes at signalized intersections. According to the probability and combinatory theory, a mathematically exact model is developed. The proposed model can be applied to share lanes either with left-turn or with right-turn movement. Respectively, by extending the model, also the capacity for the Right-Turn-On-Right situation can be exactly calculated. In contrast to the regression functions in the US Highway Capacity Manuel, the proposed new model satisfies all necessary boundary conditions. The results of the model fill out a gap in the current procedures of capacity estimations at signalized intersections. The proposed model has the capability to be incorporated into the exiting highway capacity manuals and other regulations. The model in this paper is developed for fixed time controlled and isolated intersections. In the future, an extension to actuated, adapted or coordinated intersections is expected.

Base travel demand forecasting model link volumes may be accurately calibrated at a screenline level to within ±5% of traffic counts, but intersection turning movement volumes, dispersed from or converged to the calibrated link volumes, may be quite erratic. To capture traffic pattern changes at intersections with respect to transportation improvement projects or/and land use changes, one can not just "read off" raw simulated turning volumes from a planning model, but requires intersection post-processing to project future turning movements with confidence. To address the intersection post-processing problem, the City of Bellevue has used an Intersection Post-Processor for 17 years to project future intersection turning movement volumes based on an iterative and semi-automatic procedure. The procedure was initially derived by Furness and later modified by Mekky — proportionally to the base year actual turning volumes, the algorithm distributes modeled arrival link volumes while maintaining modeled departure volume constant, or the other way around iteratively until the differences between the results and link volumes desired are minimized within an accepted error. The Bellevue Post-Processor has the procedure enhanced on two levels: 1) adjust existing turns to future turn changes due to future network changes, based on several mathematical solutions; and 2) balance future re-calibrated (or adjusted) intersection link arrival and departure volumes to the Level I adjusted turns. This paper not only discusses the mathematics behind the Bellevue Intersection Post-Processor, but also presents a general and better solution out of several possibilities to intersection post-processing problems. It makes it possible to fully automate the Intersection Post-Processor, and thus save modelers' tremendous amount of manual time. The presentation will benefit transportation forecasting and analysis communities in obtaining more reasonable and accurate forecasts of future intersection turning volumes by using base year counts and travel demand forecasting models, and by designing a more efficient user program, especially when dealing with a large number of intersections in an urban setting.

This paper describes a systematic bottleneck identification and analysis for Oregon Highway 217 in the Portland, Oregon metropolitan region. Bottleneck studies can reveal key information about freeway operations and traffic flow characteristics. They also provide relevant and useful tools when teaching the fundamentals of traffic operations. This study uses 20-second aggregated data collected from eleven mainline and eight on-ramp inductive loop detectors that form part of the regional intelligent transportation systems (ITS) network. The data is archived by the Oregon DOT in the Portland Archival Listing (PORTAL), a unique online database developed, maintained and housed at Portland State University. This study relies on the relationship between vehicle flows and occupancies to produce definitive proof of bottleneck activation during the morning peak period in the southbound travel lanes. Oblique plots comparing changes in flow and occupancy reveal time segments with stationary conditions and times at which transitions between congested and uncongested traffic states occur. An analysis of the data produces quantitative measurements of wave propagation speeds and queue discharge flows. Several days over a period of three months in 2006 are analyzed to confirm the presence of recurrent congestion and to demonstrate reproducibility. A comparison is made between recurrent congestion observed at the bottleneck site with non-recurrent congestion (due to an incident) observed at the same location on a different day. This research may contribute to additional analyses of this corridor including an ongoing ramp-metering study currently being conducted along the 217 corridor, and other analyses of Portland area freeways.

According to the Highway Capacity Manual, definitions of level of service for freeways are generally in terms of such service measures as freedom to maneuver, change in free flow speed, and drivers' physical and psychological comfort. These quality measures are inherently uncertain and are highly dependent on user perceptions. However, users' perception of traffic operational conditions has not been explicitly considered in defining LOS categories. This study attempt to evaluate freeways LOS and other quality measures describing LOS, based on user perception. Therefore, twenty 1-minute video clips of a weaving freeway segment were shown to users. For each video clip, users' perceptions of LOS, maneuverability, flow condition and congestion of the traffic stream were surveyed. Using fuzzy set theory, fuzzy categories for these traffic characteristics were developed. The developed categories for each quality measure were analyzed. They were also compared to the HCM LOS categories. It was found that fuzzy categories of LOS, maneuverability and flow condition are noticeably similar in terms of category range and spacing. In addition, perceived categories of these three quality measures are not necessarily similar to HCM LOS categories in terms of category range. It was also observed that for traffic conditions having HCM LOS A through E, users perceive service on three-to-four levels. The findings also suggest that when traffic conditions have HCM LOS A through E, the congestion within the traffic stream is acceptable for users.

This paper presents an Integrated Transportation Information platform (ITIP) based on a Multi-Agent System (MAS). A distributed ITIP system architecture is proposed based on various agents, including User Interface Agent (UIA), Information Awareness Agent (IAA) and Task Processing Agent (IPA). The main functionalities and implementation methods for the agents applied in such a system are introduced and the advantages of the proposed current system based on MAS are shown. Through use of eXtensible Markup Language (XML), an improved ITIP on the Microsoft .Net platform was implemented. The research indicates that MAS may be a possible technique to implement integrated transport information platform.

This paper introduces the main traffic information source and pre-processing method of urban expressways, corrects single-sourced traffic information, and fuses multi-sourced different-structure traffic information. In addition, it describes the short-term forecast for traffic conditions with the method of phase space reconstruction. Furthermore, the proposed method is validated based on traffic information of the Beijing expressway.

Accurate prediction of real-time short-term traffic flow is essential in Intelligent Transportation System (ITS) and is the foundation of urban traffic control and guidance. This paper proposes a new method—Online-learning Lagrange Support Vector Regression (Online-learning LSVR), which was adopted in real-time prediction for short-term traffic flow. The algorithm of Online-learning LSVR proposed in this paper and conventional LSVR were compared and evaluated using an urban traffic flow data set. Experimental results were compared showing the improved LSVR not only realized online-learning but also used fewer Support Vectors (SVs) and much less forecasting time without decreasing prediction accuracy.

Headway and speed distribution models were set up for traffic flow about on-ramp junctions of urban expressway, which was based on the analysis of subsistent distribution models and Weibull distribution function. Additionally, the graphic method and analytic method of calibrating the parameters were discussed. It was found that the graphic method could be used to calibrate a two-parameter speed Weibull distribution model and the analytic method for three-parameter Weibull distribution model of vehicles' headway directly. Finally, the models were validated with collected on-ramp junction traffic flow data in the GUANGZHOU urban expressway, and the results showed that Weibull distribution functions can describe traffic flow distribution regularity suitably, especially for the use of traffic flow with high density much better than Erlang distribution and Normal distribution.

Variable Message Signs (VMS) are becoming popular as one of the primary means to issue the real-time traffic information in Urban Traffic Flow Guidance System. The VMS can exert their best affection only when they locate on the optimal location. But when we consider the best location of the VMS, we often depended on the feeling or the experience, and lack of scientific data. This paper discusses a new method to locate the VMS, based on analyzing the intersection important degree in traffic network and the guidance obey rate in the key intersection. Lastly, the method is applied in a simulation experiment in Changchun city. According to the analysis result, we can prove the method is effective.

Method of floating car data (FCD) is effective for traffic state estimation. However, using only position and time information sent by FCD vehicles, for short road segments with long cycle time, the averaged FCD travel time could not reflect real traffic state due to the sample size limitation. A data preprocess method is proposed aiming at improving estimation accuracy at signalized road segments using existing sample data and effective green ratios. It is shown both in theoretical proofs and empirical results that the method is effective and practical.

Currently, Texas recommends at least a 200 mm thick layer of Stone-Filled Hot-Mix Asphalt (SFHMA) mix as the main structural load-carrying layer in a perpetual pavement (PP) structure. To ensure adequate rutting resistance, the SFHMA mix-design characteristic typically consists of a moderately low asphalt-binder content (about 4.2%) and coarse aggregate gradation with a 25 mm nominal maximum aggregate size. However, perpetual pavements are relatively a new concept to Texas with limited experience or documented literature including the modulus properties and performance history; in particular for the rut-resistant SFHMA mixes. The objective of the work presented in this paper was therefore to evaluate and characterize the modulus properties of the SFHMA layers (mixes) based on laboratory dynamic modulus (DM) testing. Analysis of the results based on eight field in-service PP projects indicated that the SFHMA mixes are generally very stiff mixes with high moduli values averaging 8 000 MPa at 25 °C, 10 Hz; which is structurally essential for adequate rutting resistance. The laboratory DM test results were also well corroborated by field falling weight deflectometer (FWD) and multi-depth deflectometer (MDD) surface deflection measurements; which also indicated that the mixes are considerably less temperature sensitive with very marginal pavement surface deflections less than 1 mm even under high summer temperatures of around 42 °C. Summarily, the findings of this study indicated that the structural design moduli for the Texas SFHMA mixes (for perpetual pavements) should be in the range of about 6 000 to 8 000 MPa instead of the current specification range of 3 500 to 5 000 MPa, at 25 °C.

Traditional studies show that shear failure always occurs in high temperature in high grade asphalt pavement. In this case, perpetual deformation and shear displacement will be produced under loading so as to shear destroy. At present, shear destroy appears in some new forms in high grade asphalt pavement in China, and the main causes may be changed. So shear ability of pavement needs more research. The paper discusses the shear stress distribution regularities, the influencing factors and the evaluation methods in high grade pavement, based on the Linear Elastic Multi-layer Theory and using the pavement finite-element programs. Results show that the maximum shear stress appears in 0–3cm depth below the surface regardless of the material's characteristics and thickness in each layer. The major influencing factors on the shear stress are modulus, Poisson ratio in asphalt layer and modulus in base layer. For three-layer high grade asphalt pavement structures in China, it is necessary to check the shear strength resistance in wearing layer and mid-layer. When performing the check, the exact location must be found to calculate the maximum shear stress in each layer. In addition, this paper puts forward the determination and evaluation methods of shear strength based on foregoing study results.

Accelerated Corrosion Test (ACT) method for the anti-chloride penetration performance of grout was introduced in this paper. The same batch mixed grouts were investigated by ASTM C1202 and ACT method, respectively. Test results showed that ASTM C1202 is not suitable for the grouts with the low anti-chloride penetration performance due to the high voltage involved. ACT method can evaluate the anti-chloride penetration performance of different grouts and it avoids the disadvantages of the ASTM C1202. However, the ACT method needs to be improved due to its long experimental duration.

The efficiency of traffic operation in expressway ramp section is a key factor to the effectiveness of the whole expressway system. The level of service of ramp influence area is the issue that needs to be understood in depth in order to achieve sustainable urban expressway system. The ramp traffic demand is high in urban areas such as in Kuala Lumpur capital city of Malaysia and due to the dense population in the vicinity of the urban expressway corridor this always leads towards congestion and breakdown phenomena. This paper presents a field empirical approach and presents the new Level of Service Chart that reflects local traffic conditions for entrance ramp junctions. Apart from that, this research effort can be a starting point towards establishment of Malaysian Highway Capacity Manual for uninterrupted flow facilities.

The paper presents a method for determining the optimal access spacing for expressway interchanges with crossroads. With the definition and basic hypothesis of access spacing, the characteristics of its structure and traffic flow are analyzed. From a systematic viewpoint, Kinematics, gap-acceptance theory, and probability theory are employed to establish the minimum-length-requirement model for access spacing. While modeling, the more difficult traffic maneuver of running off the ramp, finishing its interweaving and running onto the left-turn lane of a downstream intersection is taken into consideration. For an existing road, based on the comparison of the measured value and calculated value, the model is helpful for finding the reasons of congestion in the access space and taking corresponding improvement measures. Finally, the model is verified to be feasible through comparison with the simulation results of CORSIM.

In this paper, one-year automatic vehicle identification (AVI) data in Hong Kong are used to investigate the rain effects on individual vehicular travel speeds and travel choice behaviour of crossing harbour. The historical AVI data at selected paths and the three harbour-crossing tunnels in year 2006 are extracted with reference to the corresponding rainfall intensities. The rain effects on vehicular travel speeds and travel behaviour in terms of time of crossing harbour are then examined based on these datasets. It was found that vehicular travel speeds at the selected paths are significantly reduced under rainy conditions. The results also show that the proportion of travellers crossing the harbour lately is more than that of early crossing under rainy conditions. The time delays of crossing harbour are generally increased when the rainfall intensities increase.

Design and operation criteria for freeways fall short in countries which have not developed their own capacity manuals reflecting local prevailing conditions such as, vehicles, drivers and traffic environment. In Argentina guidelines of the TRB Highway Capacity Manual (HCM) have been used since early editions of the 1950's, and efforts are made to capture the effect of main local variables. This paper reports a study carried out on the Cordoba-Carlos Paz Freeway (CCPF). Speed field measurements with the floating vehicle technique were used to establish the Free Flow Speeds (FFS). Through regression analysis and other statistical methods, the effects of grades and the influence of night visibility were explored. HCM methodology estimates FFS adjusting the proposed Base Free-Flow Speed (BFFS), considering lane widths, lateral clearance, number of lanes and interchange spacing. Level terrain with grades no greater than 2% and good visibility are included as ideal conditions. The analyst is encouraged to determine FFS from field observations when the freeway has significant vertical conditions. Grades showed an important effect on FFS, and this effect may be included as an additional factor, f_G (adjustment for grade) for modifying BFFS. Tables with recommended values for Argentina are given. A moderate decrease in FFS was found on night visibility compared to daylight conditions giving an estimate of benefits of freeway illumination in night travel times, besides the well-known benefits in safety.

The HCM procedures are usually employed in Argentina to analyze level of service in Freeways. However the vehicle and drivers characteristics differ between Argentina and USA. This paper reports a study carried out on an Argentinean freeway with two lanes in each direction. Using statistical analysis the speed flow curves were obtained for each FFS. It was found that, for local conditions, average speed (S) decreases faster than in HCM. For FFS lower than 95 km/h, S begins to decrease around 300 pc/h/ln, and for FFS greater than 100 km/h, S begins to decrease even for lower flows. According HCM, S and FFS are equal when Vp ⩽ (3100 — 15 FFS). The paper also reports the procedures followed to obtain and process the data, the statistical analysis and comparisons developed, and the new speed flows curves proposed for local conditions.

Based on analysis of domestic road weather sites' disposal conditions, and aiming at dense road weather sites' shortcomings of wasting funds and energy, this paper introduces the concept of a base road weather site. It is a low-cost disposal method, and it can optimize road weather sites' disposal and give quantitative reference for disposing of road weather sites reasonably, such as location, number, and configuration. This paper introduces details regarding the disposal principle and method of base road weather sites, which haven't been used in China. It's valuable for the rapid development of the road weather information service in China and for saving funds and energy.

In order to mitigate the impacts of adverse weather on transportation mobility, traffic safety, management, and maintenance productivity, the idea of constructing an Expressway Safety Management System (ESMS) that is concerned more with the safety management demand, especially in cases of adverse weather, was put forward in this paper. The author indicated the construction concept, architecture, major functions, and sub-systems of ESMS, which consisted of six sub-systems, namely, traffic and weather monitor sub-system, road weather forecast and impact evaluation sub-system, advanced traffic management sub-system based multi-info resource, intelligent information dissemination sub-system, winter road maintenance decision-support sub-system, and emergency rescue sub-system.