Johnny, You're Wanted.

Returning late to London, Johnny gives a lift to an attractive female hitch-hiker. Some distance on, he stops to make a phone call and buy a coffee, but on returning to his cab finds the woman gone. Assuming she has hitched another ride, he continues on his way. A short time later he is flagged down by another driver, who has come across a woman lying by the roadside. The woman is Johnny's hitchhiker and she's dead.