Katy Perry is terrified of sleeping as she travels in a car - after cheating death in a horror crash when the driver dozed off at the wheel.

The I Kissed A Girl hitmaker was involved in a frightening road accident when she was 13, as a vehicle she was a passenger in flipped onto its roof.It later emerged a motorist had fallen asleep - and the singer is now obsessed with staying awake during car journeys to make sure the driver keeps concentrating on the road.After a four-hour ride to Seattle, Washington on Saturday (05Sep09), she told followers of her Twitter.com blog, Would have liked 2 have slept in car like every1 (sic) else, but since person fell asleep @ wheel when I was 13 & rolled car, no sleep in cars. Damn.