A TRAFFIC-LIGHT free world may be the wish of every commuter running late in the morning, but it could also make driving much quicker.
That is, if motoring technology advances to a point where cars can communicate with one another.
A new study from the Massachusetts Institute of Technology (MIT) suggests that sensor-based crossroads would be twice as quick as traffic lights and would allow twice as much traffic use the roads.
The study uses mathematical modelling to show that a light-free world would run smoother.
The researchers examined a scenario in which high-tech vehicles use sensors to remain at a safe distance from each other as they move through a four-way crossroads.
By removing the waits caused by traffic lights, these so-called Slot-based Intersections (SIs) speed up traffic flow.
“An intersection is a difficult place, because you have two flows competing for the same piece of real estate,” says Carlo Ratti, a professor of the practice and director of the SENSEable City Lab in MIT’s Department of Urban Studies and Planning, and a co-author of the study.
But a system with sophisticated technology and no traffic lights, he adds, “moves control from the [traffic] flow level to the vehicle level.”
Paolo Santi, a researcher in the SENSEable City Lab who is a member of the Italian National Research Council and another co-author of the study, says the greater capacity does not stem from vehicles moving more quickly. Rather, it comes from creating a more consistent flow at an optimal middle speed, at which automobiles can keep moving.
“You want the car to use the intersection for the shortest possible time,” Santi says.
The researchers use the comparison to plane boarding to explain their theory. They call it the “slower is faster approach”. When passengers board an airplane, they tend to move faster if they are in smaller clusters that keep going steadily, as opposed to a scenario in which everyone crowds around the entrance, creating a giant bottleneck.
Ratti thinks the intersection-first theoretical approach to urban traffic will prove beneficial: “Because the intersection is the crucial point, once you solve the intersection, it has a beneficial effect on the whole system.”
To embed this post, copy the code below on your site
have your say