Sue Kiesewetter

Special to The Cincinnati Enquirer USA TODAY NETWORK

WEST CHESTER TWP. – Economic development and worsening traffic are the two major factors contributing to West Chester Township’s decision to improve the Union Centre/Interstate 75 interchange this spring.

The project would add one exit ramp from northbound traffic at the interchange and two for southbound motorists in what is known as a diverging diamond design.

“Capacity and safety drove the whole project,” said Greg Wilkens, Butler County’s engineer. “One of the big things it will do is provide easier access on and off the interstate with less potential conflict, which means less accidents.”

Under the diverging diamond model, motorists move with the flow of traffic instead of stopping and crossing traffic, Wilkens said.

Motorists would cross over to the left side of the road while passing over Union Centre Boulevard’s bridge. Traffic signals would stop oncoming traffic during the crossovers.

Bids for the project will be opened April 16, with construction expected to begin at the end of May or early June, Wilkens said. The engineer’s office is overseeing the project.

“There’s quite a bit of land to develop around that interchange. For development to continue on pace, we’ve got to improve that interchange,’’ said Mark Welch, president of the West Chester Township Board of Trustees.

“We didn’t want the development of the central business district and surrounding area to be stymied. The traffic is so heavy getting on and off at rush hour…it can take 15 minutes to get on the highway at 5 p.m.”

Calling the project ‘long overdue’ Trustee Lee Wong said the township will fund the project from a special taxing district for that area of the township.

“Traffic is horrendous during rush hour. It’s very important for commerce for West Chester, for the region to do this,’’ Wong said. “The longer we wait, the more the cost goes up. We have to do it right or go home – not just a little band aid fix.”

Since the interchange opened in 1997, southeast Butler County has seen an investment of $1.5 billion in investment resulting in 16,854,382 square feet of new corporate office, manufacturing, distribution, research/design and commercial projects, according to the engineer’s office.

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That development has resulted in more than 17,500 new jobs. Traffic is project to increase from more than 153,000 vehicles through the intersection daily to more than 187,000 by 2038, Wilkens said.

Wilkens said the project has been under study since at least 2006 but at that time the Ohio Department of Transportation deemed the design too risky because it was an unproven design.

The first opened 10 years go in Springfield, Missouri, connection Missouri 13 with Interstate 44. Since then more than 100 have been constructed in the United States, including one each in Franklin and Wood counties in Ohio.

A plus to the project is a center walkway for pedestrians, with a wall on each side to separate from traffic, Wilkens said.

“I’m big for connectivity,’’ Wong said. “This is the only way to do (cross over I-75) it safely.”

Originally estimated at $13 million, Wilkens said the cost has increased. West Chester Twp. will issue bonds to pay for the project.

Beginning Monday some lanes of both eastbound and westbound Union Centre Boulevard at the interchange will close overnight for five nights so that soil tests can be done at the bridge over I-75. Traffic will be maintained.

Closures will take place from 9 p.m. to 6 a.m., weather permitting