Enhancement of transport safety through Cross Modal Switching

Transport safety has a direct impact on people’s lives despite considerable improvements in recent decades. By treating transport modes independently and not taking full account of modal options available, policymakers have overlooked potentially important and low cost contributions to overall passenger safety.

This thesis investigates the extent to which Cross Modal Switching (CMS), encouraging users to transfer to safer modes of transport, can be deployed as an instrument of transport safety policy.

Research was conducted to establish the safety differences between modes on specific journeys, taking account of composite risks including all transport modes used. Primary research used surveys and qualitative interviews to target three different groups to understand their views on transport safety, willingness to switch modes, reasons that would cause them to switch and modal perceptions on risk and travel behaviour. The feasibility of promoting CMS was assessed by measuring substitutability between modes and calculating cross-elasticities using data from the empirical surveys conducted and previously published work.

Cost benefit calculations were made using monetised risk and the cost of fares subsidies to assess the net safety benefits for three selected journeys.

This analysis shows that there is a marginal justification for CMS as a tool within an overall integrated transport policy that considers safety in all modes simultaneously. This must recognise that the absolute safety benefits are not very large relative to other benefits, although the relative size depends on the manner in which changes of consumer surplus are treated in the CBA. CMS can be demonstrated to be cost effective in low risk modes, relative to larger infrastructure investments only yielding marginal safety improvements. Further research, using a larger sample of journey net benefit calculations, is thus required to validate the case robustly for CMS, identifying beneficial opportunities for modal switching on specific routes and target modes.