PhD Thesis, University College London


Modelling Interactions between Bus Operations and Traffic Flow

by Paulo Silva

Abstract

Simulation is widely used in urban traffic network studies. However, existing tools largely ignore or unrealistically simplify important details of bus operations and their interactions with other vehicles. This thesis describes a model developed to represent buses and their related operations in traffic microscopic simulation.

Three main aspects of bus operations to be represented are identified - the manoeuvres that take place at and near bus stops, the bus lanes and the time scheduled arrival of buses at stops. SIGSIM is the microscopic simulation software selected to host the proposed model.

The changes made to SIGSIM are based on the response of drivers not only to the behaviour of the vehicle immediately in front of them (the conventional car-following approach) but also to those within a wider area that includes adjacent lanes. The proposed model adopts a flexible approach to lane discipline and positions vehicles in two dimensions to include their lateral displacements from the axis of the lane. A behavioural element originally present in SIGSIM is expanded to account for the drivers' willingness to act politely or not in a range of situations. The model is also adapted to allow vehicles to be generated not only randomly but also deterministically.

The processes of calibration and validation involve the development of a method that compares longitudinal and lateral positions of individual observed vehicles with their equivalents in the simulation. A case study is presented in which the model is used to simulate the operation of different bus stop layouts and predict their traffic impacts. Traffic composition for different arrangements of bus lanes is also analysed.


If you wish to receive a copy of this thesis or leave a comment, please fill in the form below, including your email address if a reply is required. Select the Submit button to send the form.

Subject:

Request:

Comments:

Your name:

Email address:

Institution:

Address:

Submit the form:


Return to the Centre for Transport Studies site or to UCL home page.
 Please note that any views expressed here do not necessarily reflect UCL College policy. No claim is made, explicit or implied, about the suitability of any data presented here for any purpose. All rights are reserved by individual members of the Dept., the Dept. itself, or UCL as appropriate, unless otherwise indicated. Any links to pages provided by individuals in the department are done so on the understanding that they agree to abide by the College and draft UCL Guidelines.


Last updated Dec '01
Please send any comments or queries about this web site to the webmaster