Last year, West State Street and Veterans Memorial Parkway in Boise were reconfigured to speed up traffic by eliminating left turns. The Ada County Highway District has had to retrain drivers to learn what is, for Southwest Idaho, a new way of turning left.
Now a similar approach is being considered 3 miles west, where State meets North Glenwood Street to the south and Gary Lane to the north.
Left turns would be prohibited from State Street, as they are at Veterans Parkway, and replaced by what is variously called a median U-turn, thru-turn or Michigan left.
Drivers must travel straight ahead through the intersection first, then make a U-turn back toward the intersection, and finally make a right turn onto the street they want to turn onto.
Left turns would still be allowed from Glenwood and Gary. Plans call for having three lanes that could turn left from northbound Glenwood onto westbound State Street, up from two now. Gary, with less traffic, will continue to have one left-turn lane.
While a final decision has not yet been made, the median U-turn was the preferred alternative among four road designs considered by the Idaho Transportation Department and ACHD.
“This design does a good job of reducing conflicts at the intersection, improving through movements, allowing for transit opportunities while still having solid bicycle and pedestrian facilities for access to high-interest areas such as the Greenbelt,” Jake Melder, a spokesman for ITD, said in an interview.
The intersection is the 16th busiest in Ada County, according to ACHD figures from 2017. More than 60,000 vehicles a day pass through. Twelve injury accidents were reported between 2013 and 2017, according to ITD figures.
The ‘Michigan left’ turn
Median U-turns have been used in Michigan since the late 1960s. Crashes have been reduced by 30 to 60 percent, with even larger decreases in head-on and rear-end crashes, Michigan reported.
The concept has since been used in a number of other states, including Utah, Arizona, Louisiana and Ohio.
Median U-turns were put into use at State and Veterans Parkway in November, after a yearlong $13 million construction project. Both Melder and David Corcoran, project manager for ACHD, said they were pleased with the results on the road, which serves 38,298 vehicles a day. It is the county’s 23rd busiest intersection, with six injury accidents reported between 2013 and 2017.
“It’s been functioning really well,” Melder said. “I have seen much less congestion at the intersection, which was a daily occurrence before.”
But Richard Llewellyn, president of the North West Neighborhood Association, which covers the area west of Gary Lane and north of State Street, said he hopes the two agencies will formally study how the median U-turn at State and Veterans Parkway is working before committing to use the same design at State and Glenwood.
“There may be design elements that could be improved,” Llewellyn told the Statesman in an email.
He said he’s also concerned that the intersection may be too dangerous for pedestrians and bicyclists to cross when State Street is widened to seven lanes.
“Parents I talk to, even with teenagers, often do not allow their children to bicycle or walk down to the river or Greenbelt from Gary Lane as they consider the intersection just too dangerous,” he wrote.
The latest State Street revamp
The project is part of a $42 million makeover of State Street between 23rd Street and Glenwood, a distance of four miles.
First came the State/Veterans Memorial project.
Now, ACHD crews are working to realign Collister Drive on the north side of State Street so it runs west of Terry’s State Street Saloon. That project is scheduled to be finished this fall, ACHD spokeswoman Natalie Shaver said.
Next year, ACHD is scheduled to realign Pierce Park Lane to give drivers coming onto State Street better vision. Pierce Park now enters State Street at a 50-degree angle, making it difficult for drivers turning onto State Street to see other cars, pedestrians and bicyclists heading east. The work will improve the angle to 86 degrees, closer to the optimal 90 degrees.
Once those projects are completed, ACHD plans on widening the four-mile stretch from five to seven lanes.
Additional changes coming
Work on the State and Glenwood intersection is at least five years away, said Corcoran, the ACHD project manager.
The two agencies are working together on the project. The highway district has jurisdiction over State Street east of Glenwood and on Gary Lane. The state maintains Highway 44, which includes Glenwood and State Street west of Glenwood.
Other changes that are planned include:
▪ Access to the Walmart store on the south side of State west of Glenwood would no longer be allowed from State, across from Saxton Avenue. Instead, a new entrance would be created 325 feet farther east, at the same spot where westbound cars looking to head south on Glenwood would turn around. That is 625 feet west of the State and Glenwood intersection.
▪ The traffic signal at Saxton would remain and a light would be added at the new store entrance. It hasn’t been finalized, but it’s likely there will be two westbound turn lanes at that spot, one for cars entering the Walmart parking lot and another for vehicles making the U-turn, Melder said.
▪ Another signal would be installed 600 feet east of the intersection, again at a spot where eastbound cars could make a T-turn to go north on Gary Lane.
What drivers think
The Statesman went on Facebook to ask drivers what they think of median turns.
Boise resident Barry Ballew first thought the idea was lame but wrote that it seems to be working to move traffic through more quickly at State and Veterans Memorial Parkway.
Boise resident Ted Eisele agreed. “So far it seems to be working,” he wrote, “although the pedestrian crossing east of the intersection is an odd aspect I think will lead to accidents and injuries.”
Nampa resident Ron Boyack questioned the energy efficiency. “It’s a waste of gas during low traffic hours,” he wrote.
Boise resident Ruth Cook said she has not used the U-turn lanes but has witnessed westbound State Street drivers cutting across three traffic lanes unsafely to be able to head south on Veterans Parkway.
“I think it is only a matter of time before an accident of some significance happens there,” Cook wrote. “People heading east are usually going 35 mph or better nearing that intersection, and those cars making the turn aren’t so obvious, especially when you are driving in the outside of the three eastbound lanes.”
ACHD engineers have been closely monitoring the intersection and have reported no problems, Corcoran said.
“As far as we can tell, it’s working pretty well right now,” he said.
Future median U-turns
Down the road, ITD is looking at installing median U-turns on Karcher Road in Nampa and possibly on the U.S. 20-26 corridor between Boise and Caldwell, Melder said.
“Alternative intersections are coming to the Valley on state highways, whether they’d be thru turns or other types of intersection designs,” Melder said. “They do a better job of moving traffic.”
ACHD is looking to install a median U-turn at Cole and Victory Roads in Southwest Boise.