Book excerpt: Evidence has come to light regarding the impact of benzene emissions from road transport, the incidence of asthmatic attacks and the possible toll of particulate matter from diesel engines on human health. This book examines the issues and argues that, without a fundamental change in policy, it is inevitable that the transport sector will continue to impose increasing costs on the natural environment, human health and the economy. It also quantifies the external costs of road transport and suggests new measures, such as road pricing and financial incentives, to pave the way to a sustainable transport system.