Humans are highly mobile but at a price: over a million people are killed annually on the road, at least 30 times as many are injured, of whom one in ten may be permanently disabled. How can we design a road or highway or transport system so as to provide both a high level of mobility and a high level of safety? For too long, from the perspective of the road user, highway engineers have had to employ their intuitions, personal experiences, shared know-how and a suck-it-and-see approach in many elements of highway design. Now the science of human behaviour can provide both fundamental knowledge and principles to enable matching roadway and transport system design to human strengths, limitations and variability in performance; an understanding of human contributory factors in accidents; and the undertaking of informed safety audits and reviews. This book aims to help you ask the right questions about the issues raised.