Both would have specialised traffic-responsive traffic lights to help improve the flow of traffic.

BBC: ?2m bid made to rid C&G roundabout of congestion

During its first tour of London's roads, one of the Fuel Cell Black Cabs excelled in rush-hour traffic, with smooth and responsive acceleration provided by the fuel cell and electric motors.

ENGADGET: UK's first fuel cell-powered black cab hits the streets of London

The populace was so responsive that we had two weeks of glorious, traffic-free roadways, and the promised traffic nightmare failed to materialize.

FORBES: Carmageddon Is Upon Us!