Construction aims to fix one of the most dangerous intersections in Johnson County
Interstate 35 commuters can expect some delays in Johnson County as construction picks up this month at one of the most dangerous intersections in the Kansas City area.
Work is now underway at I-35 and West 119th Street in northeast Olathe, where the traffic volume is among the highest in the state. The $22.5 million construction project includes reconfiguring the intersection and widening 119th Street — creating three lanes in each direction from Renner Boulevard to Strang Line Road — to alleviate congestion.
“Anyone who uses that interchange knows the challenge it presents,” said Olathe Mayor John Bacon. “It’s not only difficult for those crossing the highway, but the backup on I-35 creates traffic and safety issues for people using the interstate as well.”
The crash rate in the area is 11 times the national average for comparable interchanges, according to a traffic analysis.
“The ramps show a significantly higher crash rate than average, insufficient capacity causes backups on the I-35 mainline and travel time and reliability are negatively affected,” said Therese Vink, Olathe’s project manager.
The analysis showed commuters can wait up to 15 minutes at the intersection, especially with congestion on I-35 off ramps. According to a 2018 traffic count by the Kansas Department of Transportation, around 120,000 vehicles travel through that portion of I-35 each day, with more than 30,000 traveling on 119th Street and Strang Line Road, just east of the highway.
Vink said the first phase of work is west of I-35, on the stretch of 119th Street between Kansas City Road and Barney Boulevard. Drivers should expect lane closures, delays and reduced speed limits there.
Work this month also includes widening the bridge over the railway tracks, first from Kansas City Road, under 119th Street. Traffic on Kansas City Road will also be reduced to one lane in each direction, contributing to delays.
The project includes reconfiguring the intersection as a diverging-diamond interchange. In general, the design routes traffic to opposite sides of the road. The crossover permits drivers to turn left without stopping at another light or turning in front of traffic.
The design is used at 95th Street and I-35 in Lenexa and on Roe Avenue at Interstate 435, among other places.
In addition to the added lanes on 119th Street, left and right turn lanes to the I-35 exit ramps will be expanded. And turn lanes will be extended at the 119th and Renner intersection.
The changes are expected to cut down wait times to five minutes or less, according to the analysis.
“Over time, the new configuration will improve travel time, increase safety, reduce congestion-generated collisions, improve interchange efficiency and effectiveness, and reduce congestion related environmental impacts,” Vink said.
Last year, U.S. Sen. Jerry Moran, R-Kansas, announced that the U.S. Department of Transportation awarded the city of Olathe a $10 million grant for the project. Other costs are covered by funds from the city and Kansas DOT.
Construction should be completed by spring 2022.
This story was originally published December 1, 2020 at 5:00 AM.
