The following correction was printed in the Guardian's Corrections and clarifications column, Saturday 30 May 2009

Homophone corner: "Round a corner peddled the mayor and the minister, enjoying the ride, until a large lorry overtook them".

One of Boris Johnson's missions as Mayor of London is to get more people out of their cars and on to their bikes.

But anyone who watches CCTV footage of the mayor's last outing on his own bicycle is likely to be put off for life.

On Friday morning Johnson headed out in London with transport minister Lord Adonis and Kulveer Ranger, his director of transport, to look at potential sites for new cycle "super highways". The routes are part of his plan for a "cycling revolution" in the capital.

Round a corner peddled the mayor and the minister, enjoying the ride, until a large lorry overtook them.

In what is being described as the mayor's "near-death experience", the lorry's back door then suddenly flew open, dragged a parked car into the street and smashed into another – just feet from Johnson, Adonis and Ranger.

A CCTV camera which caught the drama obscures the cyclists during the collision until 30 seconds later a figure that is unmistakably Johnson emerges, helmet in hand, scratching his head and lucky to be alive.

An aide to the mayor said: "It was pretty awful. They were shaken up and Boris was shocked. But it makes the case even more for his super highways."