The Route Masters -Running London's Roads is a six-episode documentary aired by the BBC early this year.
This video clip here is the first episode, Gridlock. This is the way the BBC introduced the programme:
"London's population has grown by a million in the last ten years. The city's roads are congested as eight out of ten journeys by Londoners are still travelled by road. This means that 25,000 Transport for London workers now face a daily battle to keep the busy capital moving. Every morning, 8,500 buses carry six million passengers - double the number carried by the underground. With 6,000 workers controlling the buses and the rest of the road traffic, 2,000 dedicated police officers work hard to keep the roads clear by attending to traffic incidents as quickly as possible, all while being overseen by the world's biggest traffic control centre which, unbeknownst to most of us, orchestrates our journeys every single day."
You can read the transcript for the first twelve minutes here.