The complexity of road transport systems can be understood in terms of the people who interact within them. As humans, we acquire information from the world around us; we interpret and make sense of it and then respond in our own unique ways. Within road systems, the factors that affect individuals, cognitively and emotionally, causing them to respond the way they do, are varied; and people act in unexpected and sometimes irrational ways. Transport system engineers and related system providers deal with materials and components that tend to perform in predictable, rational and repeatable ways. The human factors specialism brings an understanding of why people do what they do, offering those who design and operate road systems deeper insight to encourage user compliance and reduce human error.
Worldwide, more than 1.35 million people die on roads each year, and another 20 million to 50 people are seriously injured. Vision Zero is rooted in the position that serious injury and death are not acceptable consequences of mobility, and strives to achieve optimal safety for all users on roads worldwide; similarly, the intelligent transport system (ITS) whole-system approach, as established and applied in the United Kingdom (UK), uses a formal assessment framework1 that focuses attention on those areas that fundamentally advance safety for everyone who uses the transport system.
In the Vision Zero approach, road users and system designers2 share the responsibility for achieving safe outcomes. System designers apply their knowledge and expertise to make and keep roads safe for all users. Road users are responsible for following the rules. If users fail to comply with road rules—due to a lack of knowledge, acceptance or ability—system designers must take the necessary further steps to counteract people being killed or seriously injured. The ITS whole-system approach aligns with the Vision Zero principle of shared responsibility—in the integration of people, processes, infrastructure, vehicles, technology, and associated data, to form safe and efficient environments.
Both of these Safe System approaches consider that people make mistakes and misjudgements; therefore, road systems must be designed so that human error does not result in fatalities or serious injuries. Serious injury and death can be prevented through a collaborative, whole-system approach to road safety that considers the interdependencies and interactions within each road network.