New signals, timing shifts: How Sioux Falls is managing traffic flow

As a major construction season ramps up, efforts to help manage traffic congestion are accelerating with it.

“We’ve done a lot of work on timing the signals,” said Heath Hoftiezer, traffic operations engineer for the city of Sioux Falls.

Technology can be a friend when it comes to managing traffic. The city’s traffic division is able to monitor areas of town and adjust signals accordingly through a network of cameras and sensors.

With Cliff Avenue closed near Lincoln High School, for instance, vehicle numbers have swelled on nearby Minnesota Avenue.

On Minnesota from 41st Street to the Interstate 229 ramps “is probably the biggest congestion area … but it’s adding traffic all the way through,” Hoftiezer said.

From 18th Street to I-229 on Minnesota Avenue, an adaptive traffic program has led to a 140-second cycle through the intersections.

“We have it cranked up for a 70-second window of green time at each intersection, trying to push traffic through,” Hoftiezer said.

It’s a balancing act, though.

“One of our limiting factors is we can only give so much time to Minnesota Avenue without backing up the interstate ramps, which is a dangerous situation,” said Troy Miller, principal traffic engineer.

On the east side, where the intersection of Arrowhead and Veterans parkways is closed, “people aren’t enjoying the detours, but we’ve been able to do quite a bit with the signals over there to basically constantly see what’s going on and make it the best we can,” Hoftiezer said.

At East 26th Street, for instance, there’s a 92-second phase for westbound traffic in the morning.

“We’ve got crazy numbers on some of those intersections to get traffic through,” Miller said. “It’s one of those things we’ve been watching from a sensitivity standpoint.”

There are multiple temporary signals along Six Mile Road and Madison Street.

The intersection seemingly causing the most angst is 26th and Six Mile, where one vehicle attempting to turn left can back up others for a long stretch.

“At that one, try to avoid turning left if at all possible,” Miller said. “The vast majority of the time it’s running pretty decent, but it doesn’t take a lot of people to really back up that intersection.”

Along South Veterans Parkway, where the next phases of the project are under construction east of Cliff Avenue, the entire stretch of road now is 50 mph except through work zones.

“We’re going to be making timing adjustments on Veterans Parkway,” Hoftiezer said. While many intersections are striped for one left turn lane, dual left lanes will be opened up.

Timing adjustments also are coming in more established areas of town.

Controllers on 10th Street from the viaduct downtown east to Sycamore Avenue are being modernized.

“We’ve started on Franklin (Avenue) through Jessica (Avenue) already and have programming switched around, so that will be better traffic flow,” Hoftiezer said.

The city will do the same on Louise Avenue between 57th and 85th streets.

New signals in place, on the way

Some permanent new traffic signals already have been installed this season — and more are on the way.

• 57th Street and Graystone Avenue

This southeast Sioux Falls intersection has a new signal up to help manage heavier traffic volume.

“Kwik Star going in really jumped the volume and all the apartments to the south too,” Hoftiezer said.

• Sixth Street and Veterans Parkway

Newly installed, this signal will help with traffic flow as the city finished improvements to Sixth Street in May.

The signals for other segments of Veterans Parkway will be installed as roadwork is completed.

• 17th Street and Cliff Avenue

After feedback from the neighborhood and further study, this signal is returning.

While volume doesn’t quite support it, the site distance that was built in the 1980s combined with the speed limit allows the city to reinstall a signal to support safety.

It’s expected to go up this summer, but “the lead times get long for cabinets and poles, and it all depends on … when they get those in,” Miller said.

38th Street and Cliff Avenue

By the start of the school year, the hope is that a midblock crossing for Lincoln High School will be ready at 38th Street and Cliff Avenue, which will bring another signal.

“The other one is we’re relocating 41st to the north to tie into the school parking lot, and that will be signalized,” Hoftiezer said.

Take a look

The city of Sioux Falls offers public access to many of its traffic cameras.

To check conditions before you head out, you can watch the intersections from here.