Formula One World Champion Lewis Hamilton took to the wheel in a London black cab to back an anti-drink-drive campaign.
More used to high-powered top performance racing cars, Hamilton teamed up with double world champion Mika Hakkinen for the trip as part of the Johnnie Walker responsible drinking programme.
The pair hailed the public transport drivers who get people home safely as "the real champions" behind the wheel.
Hamilton said: "Our message is simple - never drink and drive. If you are out celebrating, use a designated driver, whether that is a taxi, bus, tube or train driver or a friend who doesn't drink that evening.
"Ever since I passed my driving test, whenever I go out with my friends I'm always happy to be the designated driver. That way I know everyone gets home safely."
Hakkinen said: "Lewis and I want to use our profiles positively and try to change attitudes.
"It's great we've been able to come to London and highlight the real champions, the people who get us home safely every day of the week."
The champions drove black cabs across London's Tower Bridge towards City Hall to join forces with professional drivers from Transport for London.
Last year, 460 people were killed and approximately 1,750 seriously injured in the UK as a result of drinking.
London Mayor Boris Johnson said: "Too many lives are tragically wasted through drink-driving accidents, so I hope that the message really gets through by having Lewis and Mika, two of the world's most talented and renowned car drivers, leading the call for people to think before getting into a car."
