Many books focus on individual differences and how those relate to traffic safety, such as accident proneness, gender differences, age, alcohol, and the effects of drugs. Others focus on the safety effects regarding the vehicle, such as airbags, anti-lock brakes, navigation systems, intelligent cruise control and other new gadgets coming continually to the vehicle. Even though these topics are undoubtedly important for traffic safety, this book takes a unique approach as it focuses solely on the road environment. Designing Safe Road Systems provides the background for those who want to know more about the effects of road design on driving behaviour. It uses a systems approach to allow a better understanding of why and in what circumstances drivers may commit errors. This understanding will ultimately lead to road systems that prevent (fatal) errors from occurring. This book contains an overview of the current models and theories about human performance and human behaviour in traffic that are relevant for all those involved in designing safe road systems. The central theme of this book is how design principles can reduce the probability of an error while driving. The authors demonstrate how knowledge of human factors helps a road authority to better understand how road users behave. They argue that in many cases the design of the environment can be further adjusted to human capabilities, and that safety should be considered a system property to be built into the road system.