Williams has used a wheelchair since a car accident in France, on 8 March 1986, rendered him tetraplegic. He was driving with team sponsorship manager Peter Windsor in a rented Ford Sierra from the Paul Ricard Circuit to Nice Côte d'Azur Airport when the incident happened. Williams had been at the circuit to watch the testing of the team's new Williams FW11, but as a keen long distance runner, he was returning to the airport following the trials because he wished to compete in a fun run in London the next day.