Build a spiffy $646 million bridge over the St. Croix River and traffic is sure to come. And there has been a lot of it on Hwy. 36 ever since the new mile-long bridge connecting Oak Park Heights, Minn., with St. Joseph, Wis., opened Aug. 2.
The new crossing was meant to reduce congestion in downtown Stillwater, and that goal has been achieved. But there has been so much traffic on Hwy. 36 during rush hours that commuters have been caught in backups because stoplights at five intersections have not stayed green long enough to handle the huge volume trying to get through.
The Minnesota Department of Transportation is aware of the situation, said Kevin Schwartz, a signal engineer. This month the agency is taking steps to improve the traffic flow by retiring signals at Lake Elmo Avenue, Manning Avenue, Washington Avenue/Norell Avenue, Oakgreen Avenue/Greeley Street and Osgood Avenue.
Specifically, MnDOT plans to keep signals green for Hwy. 36 drivers for an additional 20 seconds during peak periods in hopes of reducing bottlenecks that have formed between 6 and 9 a.m. and 3 and 6 p.m. on weekdays.
When the tweaks take effect, Hwy. 36 drivers will have green lights for 2 minutes, 30 seconds in the mornings and 2 minutes, 50 seconds in the afternoons, which extends the green light cycle by about 13 to 15 percent.
The 4-mile stretch has always been somewhat of a slow flow. With longer green lights, the aim is to keep vehicles moving. That in turn can help increase the highway's capacity, Schwartz said.
In 2016, traffic counts showed that roughly 42,000 vehicles a day passed through the intersection of Hwy. 36 and Lake Elmo Avenue, the westernmost traffic signal where bottlenecks often form. That number was about 38,000 just east of Manning Avenue. Manning is a popular route for drivers attempting to bypass Stillwater, which may explain the lower volume.
But now with a straight shot across the St. Croix River to Wisconsin, more drivers may be staying on Hwy. 36. While it's too soon to tell exactly how many drivers are using the new bridge, anecdotal counts show there has been an increase in highway traffic, Schwartz said.
MnDOT will continue to monitor traffic and fine-tune things, Schwartz said. "We have to be careful we don't create unnecessary delays for cross streets."
Follow news about traffic and commuting at The Drive on startribune.com. Got traffic or transportation questions, or story ideas? E-mail firstname.lastname@example.org, tweet @stribdrive or call Tim Harlow at 612-673-7768.