What was the Winston Churchill car accident about?

It happened in New York City on December 13, 1931. As the story goes, Churchill was driving in a cab down Fifth Avenue looking for the home of a friend who's address he had forgotten. When he thought he had recognized the house he asked the driver to stop. He was then struck by a car crossing the street when he supposedly forgot that the rules of traffic flow in the U.S. are opposite of the U.K.