Traffic Lights And The People Behind Them

Ever stuck at what seems like an absurdly long red light at a Grand Traverse area intersection? And then wonder “who’s in charge of these traffic lights, anyway?” Here’s your answer.

Three agencies actually have responsibility for the traffic signals in and around Traverse City; those within city limits are under the purview of the city government, while the county is in charge of the rest countywide. The exceptions are state trunklines -- roads such as M-72, US-31 and M-37 -- that are maintained by the Michigan Department of Transportation (MDOT).

“They are installed at busier intersections based on the traffic volumes,” says Garrett Dowd of MDOT. He says they have specific timing plans to optimize both the movement of traffic at the individual intersection and to coordinate the flow of vehicles through multiple intersections.

That flow will be helped along by the installation of so-called intelligent transportation systems, a.k.a. adaptive traffic signals, in 2020. These signals communicate with one another based on actual traffic demand to optimize timing as a whole rather than individually. “In three years we’ll begin construction. They take some time to install and test,” says Dowd.

That’s a step beyond where things are now. Garth Greenan, traffic services supervisor for the Grand Traverse County Road Commission, says there are traffic detection systems built into the pavement in numerous areas in the county. “A car or motorcycle (on the sensor) sends a message back to the signal. If no one is in the left turn lane, it won’t get an arrow,” says Greenan. That can be problematic if a vehicle is not pulled up close enough to the signal to set off the sensor, which can cause traffic to back up until the vehicle actually pulls up close enough to the signal to set off the sensor.

Traverse City Engineer Tim Lodge says the city’s lights are coordinated with those of MDOT, and many change from full signals to blinking lights at a certain time of night when traffic is minimal, then go back to their regular sequence come morning. 

Personnel at all three agencies recognize that traffic lights sometimes annoy drivers. Waiting to get through one light only to find it happening at the next light and the one after that can get drivers steamed. “Yes,” admits Lodge. “People get frustrated.”

One option for places where the lights do cause stop and go traffic is actually removing the signals. “Airport Access and Parsons is one I hope to look at. Maybe remove the signal and put in a roundabout,” says Lodge.

Another is the installation of new lights, as with the ambitious upcoming plan by MDOT. But new signals are costly; Lodge says the base cost is in the $50,000 range. The new advanced, “smart” ones can run three times that amount. No wonder he says the city is in a maintenance mode. “We’re not investing,” says Lodge.

Greenan says he and his counterparts try to ensure that traffic signals are working properly, but they also rely on the public. “Every five years we look at the signal to see if it needs adjusting. More often if there are complaints,” he says.

They also test them in other ways. Lodge says the city had a summer intern drive across town from Airport Access Road to 14th Street using several different routes. He says the trip took from 11 or 12 minutes to 18 minutes, depending on the route. Not only was it timed, but the trip provided perspective on the amount of traffic as well as the traffic flow. “There are not a lot of traffic backups,” says Lodge. And if there is a backup, it may be just at a certain time of day, like morning or evening rush hour.

Despite everyone’s best efforts, Lodge says it’s inevitable that sometimes the number of vehicles will overwhelm the system, creating backups. But he points to a silver lining in potential traffic jams. “Most cities that are vibrant have (traffic problems). Congestion is a good thing.”