This paper presents a transport scenario to save energy without restricting mobility, by using smaller and lighter cars and more cycling and walking; it also discusses the scenario's safety problems. Possible ways to reduce energy consumption per vehicle/km could benefit from the following new technology areas: (1) increasing `overall efficiency', defined as the ratio of power at the wheels to fuel energy rate; (2) reducing driving resistance; and (3) decreasing car weight and power. Tables show the improvements in the performance of these technologies, that can be expected in the fairly near future. There is still a vast scope for improving the fuel efficiency of cars. A lighter car with a small-displacement engine uses less energy per vehicle-km than a heavier car. Growth in traffic can be controlled by a `nodal' land-use strategy, where travel inside urban nodes would be by cycling and walking, and internodal travel would be by cars and public transport. Road accident data from Denmark and Sweden show that the increased safety of occupants of heavier cars is largely at the expense of other road users' safety. To make the author's scenario compatible with current safety requirements, the behaviour of today's heavy-car drivers would have to improve.
Abstract