A new global study about traffic congestion says the Salt Lake City metro area is one of the few places in North America making significant improvement, and it could serve as a model for others.

“We’ve been pleased to uncover some positive developments in cities like Portland, Oregon, and Salt Lake City, which might serve as examples for other cities,” said Nick Cohn, senior traffic expert for TomTom, a Netherlands-based navigation software company.

It just released its annual TomTom Traffic Index with statistics about congestion in 403 cities across 56 countries, gleaned from travelers who use its navigation systems.

It found that congestion is getting worse or is stable in 75% of the cities it studied worldwide.

Among the 93 large North American cities or metro areas that it evaluated, 17 saw congestion drop last year — and the Salt Lake City area had the second-best decrease, even amid its rapid population growth.

TomTom figures Salt Lake City area drivers spend an extra 17% of their driving time stuck in traffic, down from 19% the previous year.

The 2 percentage point drop was tied with New Haven, Conn., for second-best in North America, behind only the 3 percentage point drop in Portland, Ore.

The study says Salt Lake City, Portland and New Haven improved for similar reasons: sophisticated traffic light optimization, expanded bike lanes and rental possibilities, and better transit options.

“It’s a big accomplishment with all the growth you’ve been having to have a slight decrease” annually in congestion, Cohn said in a telephone interview. “There are a lot of good things happening to at least handle the growth.”

For example, he praises work by the Utah Department of Transportation that developed a first-in-the-nation system to better coordinate signals throughout the area — better allowing groups of vehicles to move together through lights that switch green just at the right moments. It became a hot topic at national conventions and drew visits from officials in other states hoping to copy it.

“Almost all of the signals are connected" in one system, he noted. "There’s been a lot of innovative work optimizing the signals so that wait times are really reduced and the whole system is really working together as much as possible. So I think that’s certainly had an effect in Salt Lake.”

Cohn also praised added bike lanes and trails in the area, and efforts by Salt Lake City with its GREENBike rental program, along with allowing electric scooter rentals.

(Francisco Kjolseth | Salt Lake Tribune file photo) An electric scooter rider braves the rain in downtown Salt Lake City on Tuesday, Oct. 2, 2018. GreenBike was on track to have their best year yet but then Lime and Bird scooters derailed their momentum.

“Cycling facilities have been getting better. It’s hard to prove that that actually immediately reduces traffic congestion," Cohn said. But in cities where congestion is decreasing, “it’s basically where there are options for the public to make trips in different ways.”

He also notes that in recent years, the Utah Transit Authority expanded its TRAX light rail and FrontRunner commuter rail systems. Salt Lake City also is using its taxes to contract with UTA to increase bus system offerings beginning in August — again adding more options to reduce congestion and pollution.

The study liked some UDOT innovations seeking to handle congestion, making note of its recent “flex lanes” on 5400 South between Redwood Road and Bangerter Highway. They accommodate heavy rush-hour traffic by reversing the direction of some lanes during the day.

“The Salt Lake area, but also Utah in general, has been really innovative for a number of things relating to traffic,” Cohn said.

For the record, Los Angeles had the worst traffic congestion in the United States — with drivers adding 41% extra travel time to commutes while stuck in traffic. The other most congested U.S. cities were New York City (36%); San Francisco (34%); San Jose, Calif. (32%); and Seattle (31%).

Worldwide, the worst congestion was in Mumbai, India (65%); Bogota, Colombia (63%); and 58% each in Lima, Peru, New Delhi, India, and Moscow, Russia.

Ralf-Peter Schaefer, TomTom vice president of traffic information, said, “Globally, traffic congestion is rising. And that’s both good and bad news. It’s good because traffic increases often indicate a strong economy, but the flip side is drivers wasting time sitting in traffic, not to mention the huge environmental impact.”

He said his company and its products allow drivers to make smarter choices in planning routes and avoiding congestion.

“We’re working towards a future where vehicles are electric, shared and autonomous so that our future really is free of congestion and emissions,” Schaefer said. “We have the technology to make this future happen, but it takes a collaborative effort.”