London's colorful mayor, Boris Johnson, has made it a priority to get more of his constituents on two wheels. But a series of deaths on the city's roads have shaken cyclists and noncyclists alike.
The number of Londoners cycling to work has more than doubled in the past decade. On some roads, cyclists now make up more than half the rush hour traffic.
And for years, Johnson has been among them. Many think the London mayor has his eye on Prime Minister David Cameron's job.