Twin Cities urban drivers have good odds of getting a green light

Though it may not seem like it — especially if you are running late — drivers in the Twin Cities are more likely to arrive at a green light than a red light, according to a new study by researchers at the Texas A&M Transportation Institute (TTI).

The 2,094 traffic signals in Minneapolis and St. Paul are some of the most efficient in the country when it comes to keeping vehicles moving, coming in at 29th out of 101 urban areas that researchers examined.

Drivers in the two cities get green lights 64% of the time and are 1.8 times more likely to arrive at a traffic light that's green The get stuck at the same intersection for more than one cycle just 0.2% of the time, researchers found.

More than half of urban traffic delays occur on city streets rather than on clogged freeways, the study said. And a major share of those delays occur at traffic signals.

"American drivers share a common experience and sometimes a common frustration with traffic signals every day," said Luke Albert, an associate research engineer at TTI. "We've developed a way to compare those experiences from one city to another."

Researchers used crowdsourced data from vehicles moving through intersections to evaluate the performance of 210,000 traffic lights in 101 U.S. cities for a week in October 2020. They used the data to calculate a Traffic Signal Efficiency Index for each location, measuring how much more likely a driver is to come across a green light than a red light.

The data revealed Twin Cities drivers on average experienced a 15-second delay at red lights, or two seconds less than the national average, according to the study, which was funded by the National Institute for Congestion Reduction.

Drivers in Fresno, Calif., were the most likely to hit a red light and had only about a 50% chance of getting a green, the study found. Motorists in Boston, Jackson, Miss., San Jose, Calif., and Corpus Christi and McAllen in Texas had about the same odds and were among the worst in the nation.

Motorists in Boulder, Colo., enjoy the best-performing signals and are nearly three times more likely to arrive on green. Raleigh, N.C., was second best.

Traffic signals have been part of the motoring landscape since they first appeared in 1914 in Cleveland, Ohio. The new findings, study authors say, can help local transportation agency officials improve their street operations.

"Ever-worsening traffic gridlock calls for a mix of solutions," the authors wrote. "Efforts to make the most of existing roadway capacity by improving signal performance, for instance, can be more cost-effective than adding new traffic lanes or interchanges to reduce congestion."

Longer red lights might not be a bad thing, the study said. Some communities have goals to improve safety and promote biking and walking rather than optimizing signals to maximize vehicular throughput.