Despite improvements in our understanding of safe road design, safer vehicles and many public campaigns against drink driving and speeding, the number of road accidents continues to rise, with 1.35 million preventable fatalities in 2018. The UN Sustainable Development Goal target to reduce global road deaths and injuries from road accidents by 50% by 2020 is, by common agreement, going to be missed. It’s clear the sector urgently needs new thinking and new solutions.
A world of changing causes
It might seem paradoxical, but achieving compliance with government-set road safety criteria, while obviously essential, has proven insufficient to produce a radical reduction in road accidents. In part the problem has changed form as urbanisation and travel continue to develop. On today’s streets certain users are disproportionately affected: more than half of global road traffic deaths are amongst pedestrians, cyclists and motorcyclists. Road traffic injuries are the leading killer of people aged 5 to 29 and the death rate is 3x higher in low income countries.
Why these groups? A mix of increased urbanisation, growing populations, growing numbers of motor vehicles in some countries, lack of segregation of road users, all combining in new ways that lead to unsafer roads.
We believe that the best way to reduce the fatality and injury statistics is to approach the problem in an integrated manner, prioritising wider sustainability goals. Beyond core road design and layout and lighting and signage, we must design and manage road schemes differently, recognising that road safety outcomes are heavily influenced by the wider range of social, environmental, economic and not simply the technical vehicle and infrastructure related outcomes.
Safety will only improve when every road or street project takes an outcome-led or human-centred design approach. The danger of only requiring projects to meet safety compliance criteria, is that the focus on wider social/safety outcomes often diminishes over time. And with a new generation of autonomous and semi-autonomous vehicles currently being tested before their introduction onto our roads and streets, a deeper and more insightful approach to safety will be vital. Big data is also playing a role, helping us to sharpen how we design and operate our streets, highways and the related connections that we need.
The sustainable approach to road safety
Interventions which focus on wider sustainability outcomes can deliver road safety benefits. Let's look at what this means in practice:
Safer interchange design: Already common in the USA and emerging in Australia, diverging diamond interchanges (a type of innovative interchange) move more traffic through an intersection, improving congestion and journey times while taking up less road space. They also have proven safety benefits - data from the US confirms that crashes are reduced both in number and severity. The design of DDIs reduces the potential conflict points by about 50% and reduces severe conflict points from 10 to two compared with a traditional diamond interchange. Read more about this approach to efficient interchanges.
Limit central urban road traffic: As cities redevelop their centres there’s a great opportunity to improve road safety, shifting emphasis from private cars and commercial vehicles, using designs that prioritise alternative and more sustainable forms of travel. By studying local needs, travel preferences and behaviours, you can design routes that reduce prevailing traffic congestion and by reducing traffic from the core of the city, the risk of personal injury also falls. Read more about this approach in Galway, Ireland.
Design with people in mind: Research is telling us more about how human behaviour affects road safety outcomes. This can lead us to new conclusions, like revisiting the placement and presentation of road signs and other information, in line with what we now know about habitual visual scanning patterns. It could also mean pushing for greater consistency in the location of particular markers on a sign e.g. distance markers next to junction numbers. Small changes, but that lead to safer road behaviour.
A bigger vision
Core to achieving any sustainable development goal, is the need to think about the full breadth of outcomes including safety related outcomes throughout planning, design, delivery and operation of our roads and streets. This ‘total design’ ethos takes us beyond compliance with safety standards. Intensifying our focus on the wider social outcomes of road and highway projects will lead to improved road safety.