Do Intersections of the Future Have Traffic Lights?
Smart city researchers say traffic lights will go out like the horse-drawn carriages they were created for with self-driving cars and reliable Internet.
THE BOSTON GLOBE
By Kevin Hartnett
When self-driving cars rule the roads, lots of things will be different: You won’t have to worry about finding a parking spot, it will be hard to earn a speeding ticket, and, according to some forward-looking thinkers, there will no longer be a need for traffic lights.
The proposal to relegate red lights comes from MIT’s Senseable City Lab and is described in a paper published in March in PLOS ONE. Instead of drivers lining up behind traffic lights and waiting their turns, the MIT team envisions what they call “slot-based” intersections, where self-driving cars regulate their speed to arrive at a crossing just at just the right time, threading the needle of oncoming traffic.
“When sensor-laden vehicles approach an intersection, they can communicate their presence and remain at a safe distance from each other, rather than grinding to a halt at traffic lights,” explains Carlo Ratti, director of the Senseable City Lab, in an email. “By removing the waits caused by traffic lights, slot-based intersections create a system that is much more efficient.”
Along with the article describing their proposal, Ratti and his colleagues produced a video simulation of slot-based intersections. In place of a dreary four-way stop, it shows cars shooting through an intersection like high-speed photons, with a precision that would be impossible to achieve with human beings behind the wheel. Compared to the tedium of waiting for the light to turn green, it’s a marvel.
To achieve such futuristic efficiency, Ratti says, cities will need just a few technological ingredients: self-driving cars, of course, which seem to be well on their way, plus a good internet connection to synch data from each car.