Abstract:
Walking and cycling are becoming more important modes of transport in the cities of the developed world in view of increasing traffic congestion, oil prices, for health reasons, and increasingly due to environmental awareness. This paper deals with the improvement of cycling and walking infrastructure applied to the Auckland (New Zealand) region but presents a methodology applicable in a wider context. Construction of proposed cycling and walking infrastructure needs to be phased and requires a means for prioritising projects over time. Estimated usage over the life of the infrastructure is a major component of the BCR computation; hence demand forecasting is crucial in this analysis. We present a mathematical model to assess user benefits derived from project interdependencies, which enables joint assessment of projects. Our methodology also enables an analysis of how a piece of infrastructure performs within the existing network. It may be beneficial to prioritise construction of a low BCR project in order to increase connectivity in the cycle network as a whole. We call this the project bundling or portfolio effect. We estimate the benefit and costs for individual projects and also for combinations of projects. We also suggest a methodology for optimal selection of projects and present a case study demonstrating this selection methodology. For road and cycleway controlling authorities with budget constraints for new cycling and walking infrastructure, our methodology provides a project selection and prioritisation approach based on whole network benefits, rather than on an individual project basis. This may be a useful decision making aid for funders in the delivery of best value for money.