Technical approaches seek to reduce the emissions produced by road vehicles using the transport system by intervening with the vehicles being used and the fuels they are burning. By definition, these approaches address per unit emissions rather than the amount of activity causing the emissions. An exclusively technological approach may be insufficient to address the growth in emissions, for a number of reasons. First, growt h in activity continuously puts pressure on technology gains. Secondly, technological improvements can exacerbate the growth in activity through the much-debated “rebound” effect. Thirdly, an exclusively technological approach to addressing the problem.
