The Toledo area's first "diverging diamond" freeway interchange will be set up with its new traffic pattern this weekend.
Completing State Rt. 25's new configuration at the I-475/U.S. 23 interchange will require shutting down Route 25's bridge over the freeway from 9 p.m. Friday until 6 a.m. Monday, Ohio Department of Transportation officials told about 60 people who gathered Wednesday in Perrysburg City Council chambers to hear how the revamped interchange will work.
The main "diverging diamond" features are intersections at either end of the freeway bridge where traffic on Route 25 will cross over to the left side of the roadway, then back to the right at the other end.
HOW DOES IT WORK: See a graphic of the lane changes
The pattern allows left turns to be made onto the freeway entrances continuously, with no need for separate traffic-signal phases to govern those turns.
"Those left-turn movements are what really congested and bottled down this interchange," Michael Stormer, ODOT's district traffic engineer from the Bowling Green office, said to heads nodding in agreement.
"I really understand this a whole lot better than I did before. It makes a lot of sense," audience member Dan Ewing of Perrysburg said at the 45-minute program's end.
Not everyone was persuaded, though.
"To me, it's a waste of taxpayers' money," said Jim Harrick of Perrysburg, who questioned whether the distinctive layout will cure congestion the way ODOT presenters said it will, and argued the project's $8.57 million cost could have been better spent on improving other, decaying infrastructure.
Mr. Stormer had told the audience that not only do "diverging diamonds" improve traffic flow, they reduce the number of "conflict points" — where traffic crosses, merges, or diverges within an interchange — to 14, compared with 26 in a traditional layout.
Furthermore, the interchange modification doesn't require replacing or widening the Route 25 bridge, and bridge construction typically is the most expensive and time-consuming part of any project, the ODOT engineer said.
The interchange will be the second of its kind in Ohio — the first opened at Roberts Road and I-270 in Columbus four years ago — and the 90th nationwide.
At existing locations, "diverging diamonds" have reduced traffic congestion by between 15 and 60 percent, Mr. Stormer said while assuring audience members the pattern "will become intuitive based on the signs and the markings."
Besides its benefits for motorists, the ODOT engineer said, the new design will feature a bicycle/pedestrian lane down the middle — separated from cars and trucks by barrier wall — with crosswalks at the crossover intersections.
As built, the Route 25 bridge had no sidewalks or other provision for cyclists or pedestrians, and their use of the shoulders to get across the freeway has been "kind of sketchy at best," he said.
During the weekend shutdown, the crossover intersections will be finished, new traffic signals will be activated, and the new traffic pattern will be set up.
Access will be maintained between southbound I-475/U.S. 23 and Route 25 on the south side of the freeway, and between northbound I-475/U.S. 23 and Route 25 on the north side, but left turns will be forbidden and through traffic on Route 25 will have to use other roads.
Fort Meigs Road is likely to bear the brunt of detouring traffic between Eckel Junction and Roachton roads.
Once the bridge reopens, the northbound I-475/U.S. 23 exit to Route 25 will close for about four weeks for reconstruction. Route 25 will remain reduced to one lane each way for the time being, but its second lane will reopen before the project's completion.
The project includes replacing the bridge's anti-vandal fences and cleaning and resealing its concrete side walls. Combined with landscaping the city will plant around the interchange, Mr. Stormer said, this "will make it look like it's a gateway to the city of Perrysburg."