Teresa Boeckel

tboeckel@ydr.com

A new type of diamond interchange expected to handle more traffic, improve safety and last a decade longer is proposed for the Shrewsbury exit of Interstate 83, according to the state Department of Transportation.

The plans for the proposed diverging diamond interchange – also referred to as a double crossover interchange – are now available online for the public to review.

The plans also will be on display at an open house March 30 at the Shrewsbury Volunteer Fire Company, 21 W. Forrest Ave. in Shrewsbury. The hours will be from 6 to 8 p.m.

With a diverging diamond, traffic crosses over onto the "wrong side" of the road in the intersection. It is controlled by signal lights and helps to reduce the number of traffic conflicts. For example, drivers could make left turns from Route 851 onto I-83 without having to cross in front of oncoming traffic.

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Plans indicate it would help reduce traffic congestion at the interchange, including backups on the ramps that sometime spill onto the highway shoulders.

Reconstruction of the interchange – which includes building a new span on Interstate 83 over Route 851 to replace the structurally deficient bridge – is slated to begin in the spring of 2018. The cost is estimated to be $16 million to $17 million.

Two options were considered

Transportation planners looked at two options for the interchange – a tight diamond (similar to the current configuration) or the diverging diamond. But the recommendation for the diverging diamond came for a variety of reasons:

It would be able to handle more traffic making left and right turns.

It would mean less delay at traffic lights.

It is expected to handle growth in traffic through 2060. That's 10 years longer than what would be expected with the tight diamond interchange.

It would be easier to expand with more lanes in the future, if needed. That would not be possible with the tight diamond.

It would reduce the number of points where traffic crosses, merges or diverges.

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"This diverging diamond is very effective in reducing conflicts and allowing good flow," said Mark Malhenzie, senior project manager with PennDOT.

A diverging diamond interchange is being built in the western part of the state, PennDOT spokesman Greg Penny said. It is along I-70 and Route 19 in Washington and Westmoreland counties.

Other states are using the design, and with its natural flow, drivers don't even realize they're crossing over, PennDOT officials said.

The York County Planning Commission agrees with the recommendation, said Will Clark, chief of transportation planning. A diverging diamond would work at this interchange because of all the traffic that is getting on and off of the highway.

"When innovation is appropriate, we feel it is a good time to move forward with it," he said.

Local residents, employees react

Here's what some local residents and employees had to say about the current interchange and the proposal:

Shrewsbury Fire Chief Tony Myers: The exit needs to be improved to handle the traffic that is coming through the area. It's difficult for tractor-trailers, for example, to make turns at the interchange because of the design, and traffic backs up as a result. Traffic also backs up from the exit ramps onto the highway, which is a safety concern. He said he agrees with PennDOT's recommendation for the diverging diamond. It will allow traffic to flow a lot easier than a tight diamond interchange. He is encouraging anyone who uses Exit 4 to come to the open house to talk with the planners. "It's important for the public and area businesses to come, ask questions and understand it better," he said.

Greg Saubel, owner of Saubel's Markets: He drove through a diverging diamond interchange last year on Interstate 25 near Cheyenne, Wyoming. "It seemed like it worked fine," he said. Hopefully it will improve the safety of the interchange, which does have crashes.

Becky Stevenson of Shrewsbury Township: Depending on the time of day, traffic at the interchange is terrible – especially at rush hour. "I try to avoid it as much as possible," she said. She said she is looking forward to a change that might make it a little bit easier to go through the interchange. She also hopes that the construction doesn't last too long because that impacts getting across town.

Janie Stierstorfer of Hopewell Township: She, too, said she takes other roads to avoid the Shrewsbury interchange unless she is getting on the highway. She said she, too, is looking for a change "for the better."

Dennis Raab, lives in York but works in Shrewsbury: The current interchange is congested and doesn't have enough room underneath the I-83 bridge. He was not familiar with a diverging diamond, but after looking at the plans, he said he can't wait to see it. "It looks pretty cool," he said.

Other important points to know

Here are a few other quick facts about the plans:

PennDOT has been discussing the project with company officials at Johnson Controls. The company is building a new complex just east of the interchange in Hopewell Township. PennDOT is aware, for example, of the size of the trucks that will be going to the company.

The new bridge on I-83 over Route 851 will be wider. It will allow PennDOT to maintain two lanes of traffic on the highway in both directions during construction.The new span also will be wide enough in case I-83 is expanded to six lanes in the future.

Bicyclists will have shoulder space to ride through the area.

Sidewalks will be included in the interchange for pedestrian traffic.

Source: Mark Malhenzie, senior project manager with PennDOT.