Dead tired or dead drunk? Fatigue kills - The dangers of driving while tired

Drink-driving is deadly, but driving while tired can be just as dangerous.

As many as one in 10 road accidents are caused by dozy drivers, accounting for 300 deaths a year.

So how much does a bad night's sleep or a long night-time journey affect our driving?

To find out, What Car? teamed up with TRL (the Transport Research Laboratory) for this exclusive study.