Different Spaces, Same Vision
With the Vision Zero approach, road users and system designers 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 prevent death and serious injury.
Worldwide, more than 1.35 million people die on roads each year, and another 20 million to 50 million people are seriously injured.3 Vision Zero is rooted in the position that death and serious injury are not acceptable consequences of mobility, and strives to achieve optimal safety for all users on roads. Similarly, the intelligent transport system (ITS) whole-system approach, established in England over two decades ago, uses a formal assessment framework4 that focuses attention on those areas that fundamentally advance safety for everyone using the transport system. The ITS whole-system approach aligns with the Vision Zero principle of shared responsibility.
The responsibility for providing road systems that are safe for all users rests with the system designers. System designers have the greatest influence over the design of the physical space—creating a system that works by design within which road users intuitively understand how to use roads safely. The guidance from Highways England for good road design5 states, “Good road design places people and their safety at the heart of the design process.”
The design techniques required to achieve safety vary according to the type of road being considered. System designers must evaluate the influential factors affecting the environment of each road and understand how to manage them within their spheres of control and influence. For example, an inter-urban road, such as a motorway,6 operates within a different context compared to a street.
Common to achieving safety in all road spaces is the need for speed management to maintain speeds appropriate for the environment. Excessive speed is a toxin within the system. Sometimes, speed limits are reduced due to the weather, road-side activity, traffic conditions, and/or other factors affecting a road’s context.7 Speed contributes significantly to the severity of injury resulting from a crash—for car occupants in a crash with an impact speed of 80 kilometres per hour (km/h) the likelihood of death is 20 times greater than at an impact speed of 30 km/h.8 The consequences for pedestrians are even greater—when involved in a collision with a car travelling at 30 km/h the chances of survival are 90 percent, at 45 km/h less than 50 percent and at 80 km/h virtually zero.9
Effective speed management comprises a range of measures that include the design of the space and how users operate within it, setting and enforcing appropriate speed limits for the context, education of users, understanding the effects of speed in crashes and using technology to encourage behaviour change. Technology, using connectivity and additional sensors applied to infrastructure and in vehicles, such as advanced driver assistance systems, offers significant opportunity to reduce harm and create safer ecosystems through better awareness and levels of driver support.10
One design feature of motorways/freeways to support safety is the control of access—in the United Kingdom, for example, motorway regulations prohibit some types of vehicle and user, including non-motorised users, learner drivers and motorcycles with engines smaller than 50 cubic centimetres. The combination of infrastructure design features suited to high speeds—such as grade-separated junctions—with the prohibition of slow-moving vehicles and pedestrians allows an appropriate speed limit of 110 km/h.
Designers of urban spaces, however, have little or no ability to control user access, resulting in the need for much lower speed limits and consideration of all types of user and forms of mobility—both established and emerging forms. If city roads were designed to eliminate access in a similar manner to motorways, this would severely limit the functionality of the system and the space to achieve its purpose—mobility and placemaking.
Linking land use planning and the design of roads is a critical step in achieving Vision Zero. To create safer ecosystems, system designers must identify the purpose of a road, what activities will be occurring on the road, who will be utilising the public space, and then design the road accordingly,11 rather than applying standardised vehicle-centric designs regardless of context. Designing communities where people can live close to the amenities they need to access for work, shopping, leisure activities, and social and education purposes reduces and potentially eliminates the need for car travel.