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Do Lines and Signs Make Roads Safe?

Thursday, January 26, 2023

Raising and old debate a recent article asks whether traffic control regulations really make roads safer for vulnerable road users. Quite simply, it’s complicated.

We might take it for granted that white and yellow paint is splashed down the middle roads, and often along the sides, giving us clear boundaries within which to keep our vehicles. But it started somewhere and sometime, and that place and time was Michigan in 1911. The intention was to bring some order to the rather chaotic situation at the time, where people drove wherever and however, they wanted. There seems little doubt that lines and signs have helped in many ways. The argument in a nutshell is that lines and signs manage and harmonize the flow of traffic. But it hasn’t been quite so straightforward, and even from the beginning some of been critical of this approach.

The early days of road markings were eventually codified, in the US at least, into the Manual of Uniform Traffic Control Devices (MUTCD) in 1935. This standardized traffic markings and infrastructure across the US, but from the critics pointed out that rather than improving safety such a system tends to increase driving speeds, and consequently increase the likelihood of serious injury or death for vulnerable road users.

On the most extreme side of detractors sits Hans Monderman, a Dutch traffic engineer who founded the Shared Space movement. His idea is that completely removing signs, lines, and lights will lead to the safest situation. A small city in Germany tried this out, and for at least the first month after the change car accidents plummet to zero. Other examples include a street in London that removed the centre line on a street which led to reduced speed and incidents. “The reason these approaches work, Shared Space proponents theorize, is because motorists instinctively behave more safely when they feel less protected by the comforting similarity of the roads around them”.

Personal Comment:

What is the purpose of a road? A road is a complex artefact, which includes physical structures overlayed with symbols that relate to laws, which in turn are embedded in culture. Part of the debate, it seems to me, is about the purpose of the road. One purpose is transportation, both of people and goods. It is also a space where many social interactions take place, where people exercise, socialize, run marathons, and more. This aspect is clearly captured by the ‘Shared Space’ name of the movement started by Monderman. Safety is important from both angles, but it looks a bit different depending on which purpose you prioritize in how you think about roads.

If the road is seen as first and foremost a public gathering space for pedestrians, then it is pedestrian safety that is primary. This might be called the ‘public-square’ approach to roads. However, if roads are seen as infrastructure dedicated to the transportation of goods and people then vehicle movement efficiency and safety takes centre stage.

Whichever way one goes it seems to me that both sides need to be taken seriously. One way to do that would be to have a more nuanced version of MUTCD, where some roads, or areas, are seen as pedestrian centric and some are transport centric. But there is a further issue, the difference between perceived and actual safety. That issue is beyond this small post, but one worth considering and shows just how complex the issues are when it comes to roads.

Written by Joshua Bronson,
RISE Mobility & Systems