Documentary telling the stories of the people who keep London's transport network operating - from night-bus drivers and road maintenance staff to the controllers overseeing it all. The first episode reveals a city constantly on the verge of gridlock - and it falls to Transport for London staff to try to keep the system working. Tow-truck driver Sean has to deal with a pregnant motorist who can't face driving through the Blackwall tunnel, while central control room operator Chris must cope with multiple accidents blocking the roads on a Friday night.