The economic and environmental benefits of increasing maximum truck weight: the British experience

This paper assesses the impact of the increase in maximum truck weight in the UK in 2001 on traffic levels, road haulage costs and emissions. It compares the actual effects of this measure with forecasts made a year before the weight limit was raised. This forecast took account of three key factors: the migration of loads to heavier vehicles, a traffic generation effect and the diversion of freight from the rail network. The net reduction in truck-kms by 2003 was at the upper end of the forecast range, though this is likely to under-estimate the long term reduction that will be achieved when the road freight sector has fully adjusted to the new weight limit. The paper includes an historical review of the lorry weight issue in the UK, a comparison with official studies of the issue in the United States and a short discussion of the case for a further increase in maximum truck weight in Britain.