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In this report we derive a macroscopic Multiple User-Class traffic model from mesoscopic principles. These principles yield equilibrium relationships between traffic density and equilibrium velocities as a function of the current traffic conditions, the traffic composition, and the distribution of user-class dependent desired velocities, rather than these relations need to be defined exogenously. These relations encompass contributions of drivers accelerating towards their user-class specific desired velocity on the one hand, and contributions resulting from interaction between vehicles of the same or different classes on the other hand. Additionally, the velocity variance variable is introduced describing deviations from the average speed within the user-classes. We discuss several mathematical properties of the MUC equations. One of the results is an alternative model formulation, namely using the so-called conservative variables desity, momentum and energy, rather than the primitive variables density, velocity and velocity variance. Using this formulation, several new approaches are derived to numerically approximate solutions of the flow model. We discuss first results from macroscopic simulation using the developed multiple user-class traffic flow model. The simulation results are employed to investigate whether fundamental traffic flow model-equations hold. It is concluded that the MUC-model satisfies the anisotropy condition, the 'invariant personality condition', and the 'unaffected slow vehicles' condition. A test case illustrates the self-formation of congestion. Transport and Planning Civil Engineering and Geosciences

This report is an attempt to describe existing capacity estimation methods with their characteristic data demands and assumptions. After studying the methods, one should have a better idea about the capacity estimation problem which can be encountered in traffic engineering. Moreover, decisions to employ a particular method should be made (much) easier since advantages, disadvantages and other aspects concerning the application of the methods are discussed. Transport & Planning Civil Engineering and Geosciences

In this report three subjects relevant for the study of bicycle traffic are presented, giving the state of the art in The Netherlands. They were presented at a workshop of Eurobike, a consortium preparing to carry out practically oriented research about bicycle traffic in European urban areas. The general set-up of the National Travel Survey is described. This survey also includes trips made by bicycle. Some details are given about the size of the survey, the change in method to collect the data in 1985 and the response rate. The modal split as a function of trip distance and the distribution function for bicycle traffic are given as examples of results that can be derived from the survey. In the safety part statistics are given about the general fatality rate of cyclists and other modes of traffic. Two studies to determine criteria for the need for separate cycle paths are described. A study proposal for analysing safety and behaviour in tenns of risk for a mix of fast and slow traffic on an arterial is presented. The third subject is the cycle planning model Quo-Vadis that can be used to determine the best possible cycling network and the best allocation of the budget for bicycle facilities. A short description of the model and its required input is presented. The traffic model part can determine cycle intensities over the period 7 AM to 7 PM on every link of the network and the origins and destinations of the flow. The evaluation part can be used to evaluate an existing network and to assess the effect of measures improving the network. The combination of the model with accident data and the determination of yard-sticks for safety can give indications of how to improve safety. Transport and Planning Civil Engineering and Geosciences

Electrical Engineering, Mathematics and Computer Science

The growing congestion problems demand a new generation of traffic models that are applicable in the planning and management of infrastructure. The aim of this thesis is the development of a traffic model able to predict congestions and their influence on traffic operation. This model is meant for three areas of applications: research into travellers' reaction to congestion; the planning of scarce infrastructure and the optimisation of the use of scarce road capacity. This thesis has been restricted to traffic operation on motorways. It is assumed that all travellers show the same behaviour. The literature review resulted in the conclusion that the so called dynamic traffic assignment models are able to detect a shortcoming of supply of infrastructure and to give insight in time dependent effects of congestion. Two different groups of traffic models can be distinguished, the traffic assignment models that assign traffic sequential per OD pair and the simulation models that calculate traffic operation on individual vehicle level. The traffic assignment models were chosen for fiirther development because these are expected to be useful both for planning and management, due to the ability to restrain the costs of use of these models by an appropriate choice of the required level of detail. Basis of the model is a dynamic traffic assignment model developed at Delft University of Technology. This model can be seen as an extended version of the existing static assignment models. Time dependent traffic operation in a network is modelled by using sequential time periods. Capacity restraints are introduced by the use of a speed/density relation instead of a speed/flow relation that is customary in static assignment models. An adequate mathematical definition of the model is missing. It is concluded that the original model without the use of a queuing algorithm does not converge in congested situations. A newly developed queuing algorithm gives a realistic representation of congested roadways, especially in those cases where spillback effects appear to upstream bottleneck links. This representation is achieved by the determination of the speed effects on upstream bottleneck links. The speed reducing effects depend on the level of oversaturation of the involved bottleneck. The newly developed queuing algorithm resulted in a better convergence behaviour than the original model (and queuing algorithm). This is shown several elementary test cases that have been investigated with software developed for this purpose. The new developed queuing algorithm resulted also in better solutions. The calculated results match better with the expected results based on traffic flow theory. The applicability of the model remains restrained to situations where spill back effects do not have substanially impact on the route choices and where a restricted level of detail of the results is sufficient for the considered application. Application in the field of traffic management requires more practical research. An approach with simulation models should not be dismissed. Transport and Planning Civil Engineering and Geosciences

In the course of the Telematics implications Programme Transport of the European Commission Fourth Framework Research Programme much attention is devoted to evaluation and demonstration. This report is part of the DACCORD project TR1017, devoted to the development and application of co-ordinated traffic control in freeway corridors. The report presents an evaluation plan for the Fourth Framework programme DACCORD. An extensive methodology has been applied to prepare a systematic and comprehensive evaluation plan. It contains an analysis assessment objectives, specification of performance indicators enabling evaluation at distinct levels of assessment (i.e. technical level, user-acceptance, impact analysis, and socio-economic assessment) and a description of various tools for validation. The plan has been developed to be site-independent to a large extent, thereby maximising the potential for cross-comparison, by proposal of common verification and demonstration plans for distinct sites. Additionally, the evaluation plan enables harmonisation of results from other European ATT-projects. Transport and Planning Civil Engineering and Geosciences

In San Diego, California, a value pricing project has been implemented in order to make better use of the existing reversible HOV-facility on Interstate 15, just north of San Diego. In this project, paying solo drivers are allowed to use the Express Lanes. These drivers experience the benefits of free-flow travel instead of the heavily congested traffic situations on the main lanes. The price for using the Express Lanes is determined dynamically and depends on the flow of traffic on these lanes. The objectives of the research presented in the report are: (1) to determine if the project has a congestion relieving effect for the main lanes, (2) how travelers decide between the different travel options in the 1-15 corridor. Using the available historical traffic data, changes in traffic conditions on the 1-15 main lanes were examined. The project does not seem to have a congestion relieving effect. The number of participant is small and there is almost always latent demand. In order to determine how people choose between the different travel options, travel time savings for the Express Lane users were determined. The travel time savings were calculated from loop detector speed at different cross-sections and reach values up to 18 minutes. The estimated travel time savings were then used to estimate mode choice models which explain the choice behavior of travelers between spending time by traveling on the main lanes and spending money by traveling on the Express Lanes. The choice models show that wealthier people, people with a higher level of education, home owners, and woman are more likely to pay for the use of the Express Lanes. The value-of-time of program participants is approximately $31.00 per hour for commuters and $71.00 per hour for non-commuters. Transport and Planning Civil Engineering and Geosciences

The evaluation of dynamic Traffic Engineering (TE) algorithms is usually carried out using some specific network(s), traffic pattern(s) and traffic engineering objective(s). As the behavior of a TE algorithm is a consequence of the interactions between the network, the traffic demand and the algorithm itself, the relevance of TE may depend on several network design aspects. In this paper, we evaluate well-known TE algorithms using real-world and generated network topologies and traffic demands. By re-scaling observed traffic demands, we are able to observe the behavior of TE algorithms under a variety of situations, which may not be observable in reality. We identify distinct network load regimes that correspond to different behaviors of the TE algorithms. We also study the impact of several network design aspects, like network provisioning and redundancy, on the relevance of TE algorithms. We find that there are specific situations under which TE algorithms are useful. These situations depend highly on shortcomings in the network provisioning as well as on the availability of alternative paths in the network.

In traffic flow analysis several regimes are distinguished, such as congested and non-congested flow conditions. Indications exist that driving behavior differs by regime, and that it may change discontinuously between regimes. In contrast, most traffic flow models used today basically assume the same car-following behavior irrespective of the traffic flow regime. It is hypothesized that because of this deficiency, these models do not always perform satisfactorily. To clarify this issue, differences in car-following between congested and non-congested flow are analyzed with data from two sites on Dutch freeways. It is shown that, at the same speeds, passenger car drivers follow with smaller headways in non-congested flow than in congested flow. Car-following of truck drivers does not show differences between regimes. Microscopic distance gap - speed models are established for several road user classes, valid for each of the two flow regimes. To show the improvements resulting from these new microscopic relationships, the latter are implemented in a micro simulation model (FOSIM) with which macroscopic patterns in traffic flow are modeled. The macroscopic findings produced with the regime specific car-following rules show a considerable improvement in modeling performance. Transport and Planning Civil Engineering and Geosciences

The importance of investigating pedestrian safety has been evaluated repeatedly in safety studies. The present study attempts to evaluate the various methods used by previous researchers in a hierarchical process, to determine the characteristics, advantages, and limitations of each method. Two general analysis approaches (passive and active) were taken into account to categorize 169 previous types of research. In the passive approach, the studied methods were those based on crash databases, questionnaires, and post-crash field observation data; while, in the active approach, the studied methods were those based on driving simulations and videography. The result of the passive approach reveals that road users' features and road characteristics (crash database studies), and error, lapses, intentional and unintentional violations (questionnaire studies) by them were among the most important causes of crashes and conflicts. Furthermore, road users’ distractions also reported a set of factors affecting the possibility of conflicts and crashes based on post-crash field observation studies. Also, results of the active approach showed that risky behaviors are the most important factor in threatening pedestrian safety such as unauthorized speeding, non-compliance with traffic law, unauthorized overtaking by drivers, and illegal crossing. Furthermore, risk perception and decision-making processes are the most important bond between the attitude and behavior of road users in dangerous driving situations. Examining studies through passive approach would lead to identifying the causes of crashes, recognizing the attitude of road users towards safety, and determining road users' behavioral patterns in certain situations, while the active approach has led to a more detailed understanding of behaviors and attitudes of road users. The inference of the findings obtained in this study will lead to a better understanding of the behavior of road users for studies on advanced driving assistance systems (ADAS). Safety and Security Science