The improvement of bus networks based on geographical information systems

The current regulatory and planning environment means that road-based public transport in UK urban areas (with the exception of London) tends to be planned on a piecemeal basis, and there are often conflicts between the needs and priorities of operators, passengers and planners. In consequence, several local authorities are considering adopting an alternative regulatory environment using quality contracts, with a consequent shift towards centralised service planning. There are though no tools readily available to ensure this centralised service planning will lead to a situation which provides a better balance between the interests of the different stakeholders. This thesis describes the development of a methodology to fill this gap, using Southampton as a case study to diagnose issues with its current bus network, and to explore the corresponding improvement methods which could be applied based on the alternative regulatory environment. Gravity-based accessibility levels from population-weighted centroids of postcodes to key services were calculated as an indicator to measure the performance of the current bus network in Southampton. Based on the accessibility analysis, service improvements, including both route planning and frequency setting, can be developed for the Southampton bus system under the alternative regulatory environment. This service improvement problem is then solved by making use of an optimisation technique, the tabu search algorithm, developed under the environment of ArcObjects for Java. The methodology described above has been shown to work well for the Southampton case study, and the outputs from the optimisation model indicate that the model can deliver a bus network which provides a higher level of accessibility under the alternative regulatory environment. While the methodology is developed in the UK context, the general principles used could be applied more widely to improve transit network planning