Getting the Hump

How "traffic calming" is making our roads more dangerous, not less

The dangerous obstacles that are becoming ever more common on residential streets.

No doubt when driving around you have come across some of the many road hump schemes that have been installed by our enlightened local councils in recent years. You may well have felt annoyed and frustrated that someone has turned a perfectly decent road into an obstacle course, but have reminded yourself that it's a price we have to pay for making roads safer and stopping drivers from going too fast. But do they really work in achieving those aims?

Motorways are the safest roads in Britain. There are also the busiest, and the ones with the highest average speeds. The characteristics that make motorways safe are that they are wide, smooth, straight, have good sight lines and segregate the traffic flows in different directions. In contrast, an unsafe road is likely to be narrow, bumpy, winding, have restricted vision and conflicting traffic movements. So, by installing humps and other "traffic calming" features such as chicanes, councils are actually giving roads more of the very elements that are likely to make them less safe. Drivers may well fail to spot genuine hazards because their attention has been diverted by watching out for man-made ones.

The proponents of road humps often claim to be concerned about pollution from vehicle emissions, but in fact road humps increase emissions, as vehicles will use more fuel by slowing down for humps and then accelerating afterwards, than by driving at a steady speed. The green lobby may be further disappointed when they realise that humps are far more dangerous and uncomfortable to negotiate for cyclists than they are for car drivers.

If there is a need to control speed at a particular location, then surely the way to do that is through imposing an appropriate speed limit, backed up if necessary by a camera (which is another story entirely). "If you drive too fast we'll break your springs" is a pretty brutal and primitive way of enforcing the law. It's not even as if the results are consistent - some vehicles, in particular 4x4s, can traverse humps at high speeds with impunity. There have been reports from London of dangerous overtaking manoeuvres by white vans whose drivers are prepared to travel much faster along traffic-calmed roads than car drivers.

There is no direct relationship between speed and discomfort when traversing humps - indeed they may result in less discomfort at higher speeds. The deterrent to driving over them quickly is not so much comfort as fear of vehicle damage. There is also plenty of evidence that suspension components can be damaged by repeatedly driving over humps even at the low speeds intended by their designers. If humps cause damage at any speed, the argument that damage can be avoided by driving more slowly over them does not wash.

Standing bus passengers may be injured when a bus suddenly and unexpectedly jolts over a hump. Disabled people, particularly those with spinal injuries, may become prisoners in their own houses because the jarring caused by road humps is too painful for them. In the US, an organisation called RADA (Road Access for Disabled Americans) has been set up specifically to campaign on this point (click on the link to view their very worthwhile website).

Most seriously of all, humps impede access for the emergency services, meaning that vital seconds may be lost for fire engines and ambulances trying to reach an incident - and for ambulances carrying sick and injured patients to hospital. In this way, humps may actually cost lives.

It is often claimed that "traffic calming" promotes walking and cycling, but even if this is true, does it justify knowingly inflicting damage on vehicles? It is also not borne out by studies of the impact of schemes. For example, a government report on the impact of an area-wide traffic calming scheme in Old Trafford, Manchester, states "As far as street activity was concerned, whilst some residents stated that they would be willing to cycle or walk more, there was no physical evidence to that effect. However, it is a hopeful sign that people expressed this intention." Intentions, it must be pointed out, are not the same thing as actions.

Significant reductions in accidents have been claimed for some road hump schemes. But is that accidents in total, or accidents per mile travelled? Very often, humps simply shift the problem elsewhere by deterring people from driving along a particular road. They may serve a legitimate purpose in doing that, but the planners should be honest enough to admit it. It may be no coincidence that during the 1990s, when these schemes started being implemented on a large scale, the dramatic reduction in road casualties that occurred since the 1960s has largely tailed off.

Far from helping the cause of road safety, road humps do nothing to improve it and in some cases actually make it worse. They also needlessly damage vehicles and make life unpleasant for road users. They are a misguided solution to a non-existent problem. "Traffic Calming" must be one of the worst examples of Orwellian Newspeak in our language. These schemes should be honestly described as "Traffic Frustration" - which is what they are intended to do. There's a lot of truth in the saying: "There was no road rage until they invented traffic calming".

In June 2003, Barnet council in Greater London announced that they were to remove al their road humps. Councillor Brian Coleman said "The problem with traffic bumps are that they are ineffectual, damage vehicles and cause 500 road deaths a year in London. They are unpopular with residents - they want them in their own roads but not in others - and are really a waste of money. We will make Barnet a hump-free zone." See here for further details. It is probably too much to ask that other councils will follow this enlightened example.

This was followed by an excellent article in the "Daily Telegraph" by Tom Utley, in which he says:

"All this, of course, helps to explain the strong attraction that they hold for a certain kind of mean-spirited local politician. For just as the private car is the embodiment of the concept of freedom, in metal and rubber, so the speed bump represents in tarmac the essence of regulation, nannying and political interference.
"The sort of politician I have in mind stands for election swearing that he wants to make the world a better place. He will say that he is desperately concerned about the environment, and anxious above all to keep the public safe. But actually, he is in it only to boss us all around and to make our lives insufferable."