Brake lights that grow in size the harder a driver pushes them are being developed in Canada.

Zhonghai Li and Paul Milgram at the University of Toronto in Canada began by experimenting with novel brake-light configurations in driving simulators, to see what changes would indicate most clearly how heavily a vehicle is braking.

In simulator tests with 40 volunteer drivers, the scheme showed the biggest benefits in very poor visibility.

Shape-shifting brake lights could be built into cars using low-power LED arrays, say the researchers, who hope to interest car makers in the idea.