This report explores how ASEAN member states can mitigate the negative impacts of the rapidly growing number of cars on the region’s roads. More, increasingly larger vehicles consume more energy, emit more CO2 and cause more local air pollution. Among the policies to counter these trends and make mobility in the region more sustainable is the ASEAN Fuel Economy Roadmap. This study provides support for implementing the roadmap. It looks specifically at policies for making light-duty vehicles more efficient and less emitting but also provides insights for other motorised road vehicles. The report explores opportunities for aligning policies across ASEAN, considers the role of trade agreements and recommends measures for a transition towards electrification.