This paper summarises the results of an EPSRC funded research study to investigate equity implications for four proposed road user charging systems, taking account of potential benefits for public transport. The four charging systems considered were cordon pricing and distance-based pricing, both of which levy fixed charges for any given trip, and time- and delay-based pricing, where fees vary due to the travel conditions encountered. The study has used two well-established models, SATURN and CONTRAM, to represent the detailed network effects of charging in two real cities, Cambridge and York. Local network information updated to include bus services and current car demand patterns were disaggregated, from a single user class with an average value of time into three income-based groups. In SATURN, demand responses to pricing were reflected through the SATEASY elastic assignment algorithm. Results have focused on: (1) the degree to which benefits in network conditions due to road pricing, found by previous studies, aid the performance of public transport; (2) the equity implications of road pricing for car travellers alone; and (3) the combined equity implications for all road travellers. Car travel becomes more efficient and public transport becomes much more efficient with delay-based pricing. Perceived average car travel costs including charges rise under pricing for all income groups, indicating an equity trade-off between car travellers and bus passengers, assuming public transport fares remain constant. When travel costs are aggregated over all roadbased modes, the equity impact for poor travellers improves, resulting in much smaller differences by income level. However, the scale of this improvement will depend critically on the volume and income distribution of bus travellers relative to car users.
Samenvatting