Analytical models of traffic at road junctions and on inter-urban transport networks

This thesis consists of six chapters and seven appendices and describes the results of a series of research projects undertaken by me during the last twelve years. There is a common theme in that they are all concerned with the development of analytical models for the evaluation of traffic and transport schemes. An introduction to the research projects, the background to their inception and the way in which they are linked in discussed in Chapter 1. Chapter 2 describes a study related to the prediction of the capacity of roundabouts from a detailed knowledge of their geometry. The analytical gap-acceptance approach to the situation at the entries to roundabouts was calibrated and tested against a large quantity of data collected at both public road and test track layouts. The results have, been compared with a range of other theoretical and empirical relationships. A main factor governing the capacity of isolated signal controlled intersections is the magnitude of the saturation flow. Saturation flow, which is defined as the maximum rate of flow of vehicles across a stop line, may be related to a range of factors including, the amount of green time available per cycle. The study described in Chapter 3 was concerned with the identification of the detailed effects of such factors, and required the collection of a large amount of detailed information using 'event recording' equipment which had been designed and assembled under my supervision. A vehicle negotiating an intersection will be subject to delay. This delay can be considered to be made up of two elements; a 'geometric delay', which may affect all vehicles, is supplemented by the delays due to congestion as vehicle interactions increase with flow. Chapter 4 described my work on the evaluation of 'geometric delay' for a range of intersection types for use by the Department of Transport. The evaluation of new inter-urban transport systems require a knowledge of the likely demand. Chapter 5 describes the analytical models which were developed as part of a study undertaken for the Ministry of Technology, into the feasibility of a new inter-urban transport system. A large survey was performed and provided the basic data for analyses described in this thesis. Detailed results and conclusions are given in the appropriate Chapters and concluding comments are given in Chapter 6.