First phase of Johnson County Gateway interchange overhaul nearly done

Marketers have a gentle name for it. They call it the Johnson County Gateway.

Drivers have another name for it — one that evokes images of traffic jams.

“We kind of jokingly refer to it as Kansas’ answer to the Grandview Triangle,” said Olathe commuter Brent Boydston.

Boydston thinks the interchange at I-35, I-435 and Kansas 10 needs an overhaul.

“We need to fix it,” he says.

The good news is that the Kansas highway department is about to complete the roughly $11 million first phase of a massive project to rebuild the interchange.

By mid-December, highway crews are expected to finish adding two lanes in each direction on I-35 from 119th Street in Olathe to the I-435/I-35/K-10 interchange.

Anybody who drives through the interchange knows they can count on delays most every day, especially if the morning sun is hindering drivers’ views.

In the morning, drivers heading north out of Olathe back up as they merge into eastbound I-435. The I-435 backups lead to traffic jams for eastbound drivers on K-10. And in the afternoon, westbound I-435 drivers routinely back up trying to cross an expansive flyover ramp to get to southbound I-35.

It adds up to a bumper-to-bumper driving experience for the thousands of drivers trying to get back and forth from growing areas in the southwest part of Johnson County.

The two new southbound lanes are intended to help break up traffic jams as drivers pour into southbound I-35 on a single lane from eastbound and westbound I-435.

The new northbound lanes, engineers said, should give drivers more time to merge onto I-35 from 119th Street in Olathe. The northbound lanes also will give I-35 drivers more time to position themselves before exiting to the tight loop ramp to westbound I-435.

But that’s just the first part of an overall project that could cost roughly $600 million by the time it’s completed.

The state has budgeted $250 million for the second phase of the interchange work. Money for the improvements will come from a 1-cent sales tax increase that the Legislature approved in 2010.

The goal is to relieve congestion in an interchange that’s used by 230,000 vehicles a day and takes drivers about a minute more on average to use than it should during rush hour. Without any improvements, the delays at the interchange are expected to grow to 16 minutes on average by 2040.

The precise details of the project aren’t completely set, but could include some of these features:

•  Adding two auxiliary lanes to northbound I-35 from I-435 to 95th Street.

•  Building two-lane flyover ramps — one from westbound I-435 to southbound I-35, and the other from eastbound I-435 to northbound I-35. The ramps there are now one lane.

•  Rebuilding the south half of the Lackman Road interchange with two separate on-ramps, one directly to I-35 and one directly to I-435.

•  Adding a new ramp at Ridgeview Road on K-10 that will force drivers to exit early to get to I-35 or northbound I-435. Currently, drivers make their decision to exit much closer to the interchange.

The improvements at I-35/I-435/K-10 will be integrated with another project currently under way on I-435 farther to the east.

The interchange project calls for the widening of I-435 to four lanes in each direction from U.S. 69 to I-35. It adds to the widening of I-435 that has been done in recent years from Metcalf Avenue to U.S. 69.

Construction on the second installment of the interchange project isn’t expected to start until spring or summer of 2014.