‘It’s a mess’: JoCo intersection one of most dangerous in KC area. $10M should help

Johnson County commuters could eventually get some relief while traveling on one of the worst bottlenecks in the Kansas City area — an intersection with a crash rate 11 times higher than the national average.

The U.S. Department of Transportation has awarded the city of Olathe a $10 million grant to reconfigure and expand the interchange at Interstate 35 and 119th Street, where the traffic volume is among the highest in the state.

“It’s a mess,” said Tim Danneberg, a city spokesman. “It is at capacity now, and traffic will stack a mile or two back during peak hours. It’s our No. 1 traffic priority.”

U.S. Sen. Jerry Moran, R-Kansas, made the announcement of the grant Wednesday afternoon. The money will help fund Olathe’s roughly $28 million project to redesign the intersection, widening 119th Street — creating three lanes in each direction from Renner Road to Strang Line Road — and building additional turn lanes on I-35 exit ramps.

The interchange has outgrown its original design as traffic continues to increase, Moran said. Improvements aim to cut down on backups and improve safety. The crash rate in the area is 11 times the national average for comparable interchanges, according to an analysis done last year.

According to a traffic count by the Kansas DOT, 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. Last year’s analysis, included in the city’s grant application, showed commuters can wait up to 15 minutes at the intersection, especially with congestion on I-35 ramps.

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The Roe Avenue overpass at Interstate 435 in Overland Park features a crisscrossing configuration known as a diverging diamond interchange. ALLISON LONG The Kansas City Star

The city plans to reconfigure the intersection as a diverging-diamond interchange, a design that is growing in popularity — it’s used at 95th Street and I-35 in Lenexa and on Roe Avenue at Interstate 435, for example. In general, the design routes traffic to opposite sides of the road just before the interchange. The crossover permits drivers to turn left without stopping at another light or turning in front of traffic.

In addition to the added lanes on 119th Street, bridges over 119th and I-35 would be modified and widened. Left and right turn lanes to the I-35 exit ramps would be added or lengthened. And right turn lanes would be built at the 119th and Renner intersection.

The improvements are expected to cut down wait times during backups to five minutes or less, according to the study.

In addition to the $10 million grant, the Kansas DOT could contribute up to $5 million for the project, while the city of Olathe plans to spend up to $13 million through a bond issue.

Danneberg said he could not confirm whether the city has secured all of the funding it needs to start the project. According to project plans, design work could begin next year, with construction starting in 2021.

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Sarah Ritter covers Johnson County for The Kansas City Star. Formerly a reporter for the Quad-City Times, Sarah is a graduate of Augustana College.