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Intelligent Speed Assist to make city driving safer

Intelligent Speed Assist to make city driving safer
Tristan Honeywill

Most drivers break the speed limit sometimes. It’s a particular problem in urban areas where pedestrians and cyclists suffer the consequences. It’s also part of the reason that my parents hate driving in London so much. Everything feels so pressured and rushed and they get drawn into it. If they find themselves in the wrong lane, rather than slow down and change, they’re more likely to get swept along and take the wrong turning than risk slowing down the traffic.

It’s not exactly surprising to learn that studies indicate that 80% of drivers speed in built-up areas, while it’s just 30% on motorways. But in surveys, drivers usually say it’s the other way around: very few drivers – just 7% – admit to putting their foot down in town.

Why do people really do it? It’s easy to forget to check the speedo when you’re in a hurry and most new cars accelerate pretty smoothly. Add to that the fact that it’s often difficult to know what the speed limit is: roads with 30, 40 and 50mph limits can look pretty similar.

Some people also just genuinely believe that they have above-average driving skills. In fact something like 70% of people think they’re above average. They can’t all be right. So there must be quite a lot of deluded drivers out there with below-average reflexes and skills.

Others no doubt think their cars are designed to be safer at higher speeds than other cars. Better brakes and tyres can reduce stopping distances, but not that much. Your reaction time doesn’t change when you drive faster so the distance you cover before you have full brake force is longer.

There are other factors too that determine the speed that people drive at in town: the type of vehicle they’re driving, the posted speed limit and the chances of being caught.

So what’s the solution? I don’t believe it’s more driver training or speed cameras. It’s better in-car information. I’m a big fan of the intelligent roadside reminders that tell you to slow down when your speed has crept up. I also like the speed-limit information on my Tom-Tom.

The European Commission is studying whether intelligent speed assist (ISA) systems should be mandatory on commercial vehicles. These aren’t old-fashioned speed limiters, which simply cap the vehicle’s maximum speed. ISA systems keep the driver informed of the current speed limit.

They work using cameras and/or map systems. The system displays the current speed limit somewhere on the dash. The driver still has the freedom to drive faster if he or she chooses, but they just get a little warning when they do. If they choose drive quite a lot faster, they get a slightly larger warning. No big deal if you decide to put your foot down on an empty stretch of motorway – within reason – and quite useful if you’ve just gone from a 50mph to a 20mph zone by a school without realizing it.

Large-scale studies of these driver information systems in places like Sweden have indicated that they could reduce the number of serious crashes in urban areas by 20% and pedestrian collisions by around 33%. With that in mind, I don’t understand why the technology isn’t being considered yet for cars, just commercial vehicles.

One consumer survey indicates that most people would be willing to pay up to £100 to have the technology embedded in their car. Given that you could probably save that on fuel in the first year, it makes a lot of sense.

Not everybody is in favour of the technology, however. A vocal minority still believes that drivers are the best judge of what speed is safe. I wish it were true. But you only have to look at how many people forget to drive sensibly in cities to realize that better in-car information, not training or enforcement, could save the lives of a lot of pedestrians and cyclists. 

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