Setting speed limits based on Safe System principles

In 2023, 65% of all pedestrian casualties, 61% of all pedal cyclist casualties, 31% of all motorcyclist casualties and 30% of car casualties occurred on roads with a speed limit of 30 mph. In total, there were 2,794 casualties on roads with a speed limit of 30 mph or less.

The RSF2030 adopts the highly regarded international best practice ‘Safe System’ approach to road safety. The safe system principles recognise that people are fragile, and they will at times make errors which can lead to collisions; however, no one should die or be seriously injured on the road as a result.

One component of the safe system "Safe Speeds" aims to establish appropriate speed limits according to the features of the road, the function it serves, and the physical tolerance of those who use it.

20 mph schemes are a fitting example of the Safe System in action, they reduce speed and the risk of collisions occurring by providing more time for a driver to react to unexpected events and if the collision does occur at 20 mph it reduces the risk of causing death or severe injury inside and outside the vehicle.

Traditional approaches for setting speed limits have prioritised vehicular traffic flow and efficiency. Speed limits have been set using mean speeds together with accident rate and are usually considered in reaction to speed-related collisions on the road network. Newer approaches are based on the safe system survivable speeds and reflect the mobility needs of vulnerable road users, such as pedestrians and cyclists, as well as their levels of safety, prioritising people.

Reducing vehicle speeds in areas where the road user mix includes a high volume of vulnerable road users, such as pedestrians and cyclists, and on non-divided rural roads, is especially important.

Even small reductions in speed lower the risk of fatal and serious collisions.

Road safety is a shared responsibility amongst everyone, including those that design, build, operate and use the roads.