Estimating time-saving benefits and mode shifts from improvements of sustainable transport modes in Cambridge, UK

This paper compares the impacts of sustainable transport alternatives to cars for small cities, in terms of mode shifts and time-saving benefits. This paper develops a new land use-transport interaction model with a detail multi-modal network, which can be quickly set up and used for small cities and their low-density exurbs. Whilst many existing models for small cities tend to focus on car traffic, treating non-car modes as a side-show, this model tests all modes on an equal footing. We use this model in a case study area that includes the city of Cambridge and its environs, a fast-growing low-density area. Three groups of sustainable transport alternatives under public discussion are tested, including Cambridge Autonomous Metro, demand responsive buses, and improving cycling and walking infrastructure. We find that in the case study area improving walking and cycling infrastructure is by far the most effective for modal shift from the car and accruing the highest time-saving benefits, as it reduces car commuting mode share from 56% to 49% for the suburbs of Cambridge. Demand responsive buses appear to be the second most effective option in reducing car trips. Metros, contrary to existing expectations, would achieve the least.