We've still got about a year before West Chester's new diverging diamond interchange is set to be complete, but township officials are already looking forward to the reduction in traffic that they hope will bring more development to the area.
"We've been looking at this for a long time," said Greg Wilkens, Butler County Engineer. "This handles traffic. It's got more capacity than a normal diamond interchange."
9 On Your Side reported on plans for the Union Centre Boulevard interchange along I-75 last fall. It will be the first one in the region.
Two similar interchanges, also referred to as DDIs, are planned in Boone County at Mt. Zion and Richwood.
The design of the interchange is what stands out, because drivers will begin crossing the Union Centre Boulevard overpass on the right side of the road, then cross over to the left side of the road to turn left, or back to the right side of the road to keep straight.
Wilkens said it is a much safer design.
"We reduce conflict points in this kind of design," he said. "Anytime you got a conflict point, you got potential of an accident."
Left turns are what traffic experts call a common conflict point, or an opportunity for collisions. The DDI design eliminates left turns with oncoming traffic.
West Chester Township will cover the cost of the interchange, which is currently estimated at $20 million. The township will use a combination of $14 million in bonds and $6 million in cash through its tax increment financing district, according to Mark Welch, president of the board of trustees.
He said the modified interchange will increase the number of cars that can travel through the interchange, which is needed for continued economic development in West Chester.
"We still have a lot of undeveloped land in the Union Centre Boulevard area," Welch said. "We want to make it attractive and we don't want traffic to be a major impediment to new developments coming here."
Since the Union Centre Boulevard interchange was built in 1997, Welch said about 25,000 jobs have been created.
"We've had over $2.4 billion dollars in investment in office space, manufacturing and retail," he said, adding that if traffic cannot easily get through the township, businesses will not want to move to the area.
"People come to work at one time and leave at 5," Wilkens said. "That is what you're trying to design around."
Ultimately, Wilkens said the current Union Centre Boulevard interchange is becoming outdated.
"We knew we had about a 20 year life," Wilkens said. "We weren't going to get much more out of that."
Meanwhile, the majority of the construction will occur without a full closure of the interchange. There are nightly lane closures happening now until Saturday, June 22 along I-75 from 8 p.m. until 6 a.m.
"We keep the lanes open so they construct everything on the outside of the ramps," Wilkens said. There will be some work on the overpass this summer. However, the portion of the construction that will involve closing the overpass will happen next summer for four days.
"All the traffic on the ramps will be maintained," he said. "But, when people exit the ramps they will have to make a right."
Other improvements of the interchange will include a pedestrian walkway through the middle of the bridge. It will have barrier walls on both sides of the walkway. There are also plans to replace add hardscaping instead of landscaping, and a new vandal fence with a decorative design that closer fits West Chester's image.
"We're making an improvement," Welch said. "You're gonna love it when you see it. Be patient."
The new interchange is expected to open by July 31, 2020.