Increasing the length of time traffic lights are on amber by just 0.5 of a second reduces the number of accidents at crossings, according to researchers at mobility consultancy Goudappel Coffeng.

They found that slightly increasing the length of the amber light cut the number of accidents or near misses caused by people driving through red lights. For example, a two-second amber light is enough to make sure cyclists have crossed safely while cars travelling at 80kph need five seconds.

The change led to a 50% reduction in the number of people going through red lights, the researchers found.

The changes have now been incorporated into official recommendations about how best to set traffic lights to local conditions and were put into effect in February.