The white boxes, which are popping up at traffic signals across the state, are apparently making your drive better.
A traffic signal on Route 130 with a communications box mounted on the support structure. A reader asked about the equipment in the box and what is its purpose. (Reader submitted photo) We answered a question earlier this month about a new type of traffic signal that tells drivers when to stop for pedestrians crossing a road.
Now, a reader has a question about the purpose of white squares he saw mounted on traffic signals on Route 130.
"Most of them are on side of road," he wrote. "Some of them on Route 130 are hanging over the fast lanes of the road. They all seem to be hooked up to solar power panels on same pole."
He also sent us photographs, which we passed on to the state Department of Transportation.
Q: What are the white squares on top of these traffic signals?
A: We asked the DOT about the boxes. Here's what spokesman Kevin Israel told us.
"The square white boxes are the receivers for radios used to transmit data from one signal to another," he said. "The traffic signals communicate via radio waves about traffic volumes and other parameters at their respective locations."
Why do signals need to communicate with each other? To keep traffic from backing up.
GOT QUESTIONS?
Ticked off about mass transit? Wondering about road construction? E-mail your questions to NJ.com's transportation expert Larry Higgs. He'll answer your questions on Tuesdays and Thursdays on NJ.com. You can also Tweet @CommutingLarry.The system is called the Sydney Coordinated Adaptive Traffic System or SCATS. It was installed at 15 intersections on Route 130 and at two on Route 32, which are feeder roads from the New Jersey Turnpike, according to TransCore, the company that designed it.
When those highways become congested from traffic leaving the Turnpike, SCATS adjusts the traffic light timing to provide longer green lights to move traffic, the company said. The system does that by measuring vehicle speeds as they roll across sensors under stop lines in intersections, according to a 2006 Rutgers study.
The system, which is in use in Mercer and Middlesex Counties, won an engineering excellence award in 2016.
The DOT has other SCAT equipment in use in the state. One is part of a $12.5 million program to network 130 traffic signals in the Meadowlands region, which includes Route 17.
Now that we've solved the mystery of how signals tell drivers when to stop and go, what questions can we answer for you?
Larry Higgs may be reached at lhiggs@njadvancemedia.com. Follow him on Twitter @commutinglarry. Find NJ.com on Facebook.