Do stoplights actually cause traffic jams?
Traffic lights have been signaling pedestrians and frustrating drivers since 1868 (when the first gas stoplights were lit in London) and 1912 (when the first electric lights went on in Cleveland). They quickly became a sign of technological progress: ‘one stoplight town’ implies that the only excitement to be had there is watching the lights change. They also interest us as mathematicians and engineers. Lights are timed with complicated algorithms, and roads outfitted with sensors to detect cars so that the computers can adjust signals accordingly. But in 2006, the Telegraph (UK) asked whether this is “the end of the road for traffic lights,” saying that they actually make roads less safe and traffic movement less efficient. A British government report on transport policy from the same year insisted that “people should come before traffic.” Ben Hamilton-Baillie, a British urban design expert, accused road planners of causing drivers’ ‘bad behavior’ by putting them in ‘unpleasant enviro
