How could one seriously count the cost of death and injury caused by road accidents, for example?

ECONOMIST: Economics focus

The number of vehicles entering the City's square mile has been cut by 25%, pollution is down by 15%, road accidents have been reduced by more than a third, and car crime has been halved.

ECONOMIST: The music of the metropolis

The wintry blast also caused problems for motorists in southeast England, with some trapped in their vehicles overnight by accidents and road closures on icy highways in Kent and Sussex.

CNN: Heavy snow snarls travel in northern Europe

Such a move, they said, would help tackle childhood obesity by providing exercise and cut road accidents.

BBC: NEWS | UK | Wales | Secondary gets 20mph speed limit

Worried by such behaviour on a two-lane road already known for accidents, the Montana Highway Patrol stopped them.

ECONOMIST: End of the last free state

Plaques in Taunton which commemorated people who have died in road accidents or in violent circumstances have been removed by mistake, it has emerged.

BBC: Commemorative plaques in Taunton removed in error

Among children aged between one and 14, by far the most common causes of death were cancer, congenital illness and road accidents.

BBC: Adventure playground

One option put forward by the trust, which researches road safety, is for a curfew on teenagers driving late at night, when most accidents involving teenagers occur.

BBC: NEWS | UK | Teenage driver deaths on the rise

Google thought big when it aimed to reduce accidents, the time and energy wasted in traffic, and the number of cars on the road by 90 percent.

FORBES: Part Four of a Six-Part Series

Earlier this year the executive set further road traffic accident targets, including the reduction of deaths and injuries by 40% and a 50% reduction in accidents involving children, by 2010.

BBC: Road deaths at 50 year low