Vehicles have traffic light control

Vehicles have traffic light control

One feature all new MTD buses include (as well as about 40 existing buses) is the ability to control some traffic lights in Champaign.

Called TSP, or traffic signal prioritization, an onboard computer and radio transmitter can give buses an extra-long green light — or can shorten a red light.

But it works only under certain conditions and only on the MTD's Green route. The feature also is available to most Champaign Fire Department vehicles, according to Glen Berger, Champaign's traffic and lighting supervisor.

"The (bus) driver has no control over it," said MTD director of market development Karl Gnadt, "and it's important to note that for us it stands for traffic signal prioritization, not traffic signal preemption. The fire department has preemption. They can come up to an intersection and get a green automatically, and everybody else gets a red. That's not what happens with us.

"Prioritization can lengthen a green light if the bus is within a certain distance and is running behind schedule, or it can shorten a red that it is approaching if it is a certain distance and behind schedule. If the bus is running on time, there is no impact on the signals whatsoever."

About two dozen Champaign intersections, most of them on either West Green Street, West Springfield Avenue, North Prospect Avenue or North Neil Street, have the feature, Berger said. Most were equipped in 2007 under a deeply discounted offer from the vendor, he said. Because of its cost, it's unclear if the program will be expanded.

"It's really proven to be a good product for the fire department," Berger said," and we did prove that the technology works."

The MTD's experience has been less satisfactory, because none of the intersections in Urbana is equipped with the technology.

"We're able to test only about half of the route to see if we can recover lost time on the schedule," Gnadt said. "It seems to be effective, but we really need the full route to be TSP-enabled in order for us to get a sense of the full impact. We need to get the Urbana intersections activated."

The Green route runs from east Urbana to west Champaign.

Gnadt said the MTD hopes to get a federal grant to help Urbana implement the TSP program there.