The American Insurance Institute for Highway Safety, an independent research group, estimates that converting intersections with traffic lights to roundabouts reduces all crashes by 37 percent and crashes that involve an injury by 75 percent. At traffic lights the most common accidents are faster, right-angled collisions.

These crashes are eliminated with roundabouts because vehicles travel more slowly and in the same direction. The most common accident is a sideswipe, generally no more than a “cosmetic annoyance”, reports The Economist (November 19, 2011).

In Carmel, US, the locals like that it is on average far quicker to traverse a series of roundabouts than a similar number of stop lights. Indeed, one national study of 10 intersections that could have been turned into roundabouts found that vehicle delays would have been reduced by 62-74 percent (at a national saving of 325 000 hours of motorists’ time annually).

Moreover, because fewer vehicles had to wait for traffic lights, 235 000 gallons (946 000l) of fuel could have been saved.

The modern, safe roundabout first entered service in Britain back in 1966, after it adopted a rule that at all circular intersections traffic entering had to give way, or “yield”, to circulating traffic.

This innovation, along with the sloping curves of the entry and exit of a roundabout (which slow traffic down), created a design that is now found worldwide.

Carmel is the roundabout capital of the US and the mayor plans to rip out all but one of his remaining 30 traffic lights.

In Africa roundabouts will save lives, the environment (fuel) and time and also maintenance and electricity.

Hein van der Walt

Florida Hills, Roodepoort