It’s Victorian London, and cholera is creeping through the streets of Soho. Famously, Dr John Snow deduced that the disease wasn’t spread via bad smells in the air as believed but through water – in particular, a single water pump.
He figured that out with data and a map. The good doctor simply plotted the deaths of infected people within the district and had the good sense to notice that they lived near the same water pump on Broad Street. As the story goes, he ended the outbreak by removing the pump’s handle. And so data analytics within cities was born.
A few years later, in 1868, the world’s first traffic light was installed, at Bridge Street near Parliament Square in London. This was before cars, but a thousand pedestrians were being killed each year on the city’s roads thanks to carriages. The signal wasn’t smart: the six-metre-high light was manually operated, with gas-powered lights. And the traffic light lasted less than a year, taken out by a sub-pavement gas pipe explosion.
Despite such explosive origins, the idea eventually spread around the world. Automated traffic lights were introduced in California in 1920, with signals that used timers. By 1928, the use of automated signals let New York slash its traffic police from 6,000 officers to 500. But it also meant pedestrians and drivers had to obey the directions of machines rather than humans to smooth urban life.
Automation required road data and traffic technology to be combined, which allowed the development of so-called “green waves”: holding all the signals going in one direction for a set of cars so they could just roll on through without stopping. This staggered system doubled commuting speeds along Sixteenth Street in Washington, DC, in 1926.
As cars took up more of city roads, authorities knew they needed to do more to address traffic. The first computerised road traffic control system arrived in Toronto in 1963, set up by Josef Kates’ consultancy KCS and its Traffic Research division, run by Leonardo Casciato. “Toronto has a traffic cop with arms seven miles long and getting longer,” explained one report from the local Star-Phoenix. “It’s a computer that already controls more than 500 traffic lights in an 80-square-mile area.”
Wires connected to sensors were buried in the road ahead of intersections, tracking the speed and direction of each car that passed using electrical induction, and sending that data to the central computer for processing to decide how long to keep the light green. The $4 million system handled 1.25 million daily trips, with the city aiming to speed up rush-hour traffic by 15 to 20%, according to local media reports. It worked even better than that: trials showed a
