The Ohio Department of Transportation plans to widen I-75 between Perrysburg and Findlay include changing the I-475/U.S. 23 junction in Perrysburg to end weaving traffic on northbound I-475/U.S. 23 between I-75 and State Rt. 25.
State officials also have drafted plans to revamp the State Rt. 25 interchange on I-475/U.S. 23 — plans that would create an unusual “diverging diamond” layout — but the project is not yet fully funded or scheduled.
Work on the junction between the two freeways, however, is set to start next summer, as part of widening I-75 from four lanes to six between State Rt. 199 and U.S. 68.
The ramp work will cost about $7 million. It will not require any more right-of-way.
“It’ll start right around the Fourth of July,” said Mike Gramza, the district planning engineer at ODOT’s Bowling Green office.
The junction’s current layout requires motorists entering I-475/U.S. 23 from northbound I-75 to merge into the left lane of a two-lane ramp from southbound I-75. Any of those drivers headed for Route 25 then must cross over to the right lane within about a quarter-mile to reach that exit.
ODOT’s plan is for the ramp from southbound I-75 to split, with one half passing under a new bridge on the northbound I-75 ramp so the northbound ramp drops in between the southbound ramp’s fork.
Drivers coming from northbound I-75 then will bear left to enter northbound I-475/U.S. 23, or right to join traffic heading for the Route 25 exit.
The parallel traffic streams approaching the Route 25 interchange will be separated only by paint, not walls, but the realignment will end the need for any motorist to weave across two lanes of high-speed traffic to get where he or she is going.
If built, the “diverging diamond” layout on Route 25, also known as Dixie Highway, would be just the second interchange of its kind in Ohio. But that project, expected to cost about $8 million, is being developed separately from the freeway project and has yet to be funded for construction, Mr. Gramza said.
“If this were funded today, it could be done by the end of 2015,” with work completed in one construction season, he said.
The design’s signature is crossovers that flip traffic over to the roadway’s left side between the two intersections with interchange ramps. The four left-turn movements to and from the ramps occur between the crossovers, so no one making a left turn has to cross opposing traffic lanes to do so.
Traffic lights govern the crossover points, and the opposite lanes are angled into those crossovers to guide motorists through the crossovers. Between the two crossovers, the sidewalk runs down the road’s middle. “It reduces the conflict points of a normal interchange” and eliminates the need for left-arrow phases at traffic signals, Mr. Gramza said.
The “diverging diamond” layout also fits in Route 25’s existing lanes over the freeway, “so we don’t have to rebuild the bridge” at a significantly higher cost, he said.
“Because of Levis Commons and surrounding commercial development,” peak traffic exceeds the existing road layout’s capacity, Mr. Gramza said — a situation likely to worsen if a proposed Costco store is built in the interchange’s northeast corner.
The revised interchange layout would boost traffic capacity by as much as 30 percent, he said.
Conversion of the Roberts Road interchange on I-270 in Columbus to a “diverging diamond” was finished in late October. It became the 18th such interchange in the nation, Mr. Gramza said.
Another such redesign was proposed several years ago for U.S. 224 at its I-75 interchange in Findlay, but officials decided against it because of several recent wrong-way crashes on I-75. Mr. Gramza noted, however, that the “diverging-diamond” layout makes it extremely hard for someone to enter a ramp the wrong way by accident.
Brian Craig, the lawyer for Craig Transportation Co., a regional trucking company headquartered on Eckel Junction Road near Route 25, said the company fears there won’t be enough distance between the revised interchange and Eckel Junction for trucks to navigate to the northbound left-turn lanes on Dixie at Eckel Junction.
If that left turn isn’t possible, “we’ll all be turning down West South Boundary Street,” which won’t be popular with businesses on that street, Mr. Craig said.
But he and his brother, Lance Craig, president of Craig Transportation, said the “diverging diamond” layout appears likely to improve overall safety at the Dixie interchange.
“No left turns in front of traffic, that will be a benefit,” Lance Craig said.
“We’re hoping that it happens soon,” said Bridgette Kabat, Perrysburg’s city administrator, who recalled ODOT officials introducing the idea to city leaders last summer. “It has come up in conjunction with improvements at [Route] 25 and Eckel Junction,” she said. “Those plans have been in the works for quite a while.”
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