Course change: Navigating urban passenger transport toward sustainability through modal shift

Staying within the 2 degrees C (preferably 1.5 degrees C) limit requires fast and fundamental system changes, also in urban passenger transport. Shifting car traffic to environmentally friendly transport modes is one central strategy to make urban transport more sustainable and climate friendly. However, in most cities car use remains high. Therefore, this paper analyzes what course change is needed regarding direction, scale and speed of change for urban sustainability and climate protection reasons. The paper analyzes the role of modal shift as a strategy in itself and in relation to land-use (avoid) and efficiency (improve) measures. The paper draws on insights from European frontrunning cities and explorative forecasting scenarios calculated with the sophisticated integrated land-use transport model Ruhr Region 2050. The paper suggests that a significant reduction of urban car use is needed (direction) that roughly equals a fast halving of car use (scale), which has proven feasible under the current socio-political conditions by annual reduction rates of 0.5 to 1.5 percentage points of the trip-based modal share of car use (speed). Significantly reducing car use requires comprehensive and high-intensive measures that go far beyond usual practices. Modal shift measures need to play a crucial role in integrated approaches with land-use (avoid) and efficiency (improve) measures because they have the potential to significantly reduce car use and CO2 emissions and because they can produce comparatively fast effects - which makes modal shift measures first aid approaches to achieve a fast bending of the curve of excessive car use and growing CO2 emissions.

Automated summary

This paper emphasizes the need for significant reduction in urban car use to achieve sustainability and climate protection goals. The study suggests that modal shift measures are crucial in integrated approaches with land-use and efficiency measures, as they have the potential to reduce car use and CO2 emissions rapidly. Comprehensive and intensive measures are required to significantly reduce car use, beyond usual practices.