This guide focuses on elements of safe road and roadside designs for road networks that can provide safe mobility to all road users

A substantial reduction in road deaths will only be feasible if concerted efforts are made, following the “Safe System” approach involving all elements of road safety, management, and delivery. This includes all pillars of the Safe System—starting from road safety management, safe roads and roadsides, safe speed, safe vehicles, safe road users, and post-crash care. This guide focuses on elements of safe road and roadside designs for road networks that can provide safe mobility to all road users, as well as complementary changes to improve speeds, vehicle safety, road user behaviors, and post-crash care. A balanced road design must take into account these complementary system elements to maximize safety benefits. The energy carried by a moving object is proportional to the square of its speed. A well-designed “forgiving roadside” ensures that this energy is dispersed in a crash, and as a result, less energy is transferred to the occupants.

Road infrastructure design plays a vital role in road safety outcomes. Safe infrastructure supports other road safety pillars by encouraging appropriate road user behavior (such as appropriate speed and correct lane position) and by providing a forgiving road environment if things go wrong. Poorly designed road infrastructure can give rise to dangerous road user behavior. One of the key realizations of the Safe System approach is that drivers make mistakes and will continue to do so, even if we can reduce how often these occur. This road user error has long been recognized as a significant contributor to poor road safety outcomes. However, roads of any given speed can be designed to reduce the likelihood of crashes occurring, and there is very clear evidence that the severity of outcomes when crashes do occur is significantly influenced by the road design. Even if a crash still occurs, improved road infrastructure can save many lives and prevent debilitating injuries.

The Safe System approach highlights that a shared response is required to address road safety. This means that road users will continue to take responsibility for their actions, for instance by being alert and compliant with road rules. However, it is also recognized that road managers and designers have a significant responsibility to provide a road system that protects all road users. This can be achieved through appropriate designs of roads.