The London congestion charge has led to a 40 per cent reduction in traffic accidents, according to economists at Lancaster University.
That's despite an average increase in vehicle speed in the areas. Before the charge was introduced in 2003 the average speed was 8.6mph, speeds now average 20mph.
Since 2003, the London congestion charge zone now sees roughly 30 fewer traffic accidents per month. As a result of this, there are 46 fewer fatalities per year.