PennDOT chooses Shrewsbury I-83 exit plan

Christopher Dornblaser

PennDOT has chosen the diverging diamond option for the Interstate 83 Exit 4 interchange with Route 851 after a meeting in Shrewsbury last month.

Here’s a PennDOT graphic of the diverging diamond interchange (DDI) option for Interstate 83’s Exit 4 in Shrewsbury. The department describes the DDI as “unique from a standard diamond interchange in that the side road traffic (PA 851), crosses over to the left side of the road at a signalized intersection prior to the bridge. This allows direct left turns from the off-ramps to merge and allows for a direct left turn on to the on-ramp. The side road (PA 851) traffic crosses back to the right side of the road at a signal beyond the bridge.”

The improvements will include two through lanes in each direction on Route 851, improvements to the ramps accessing I-83 and a new bridge carrying I-83 over Route 851, according to a PennDOT news release.

Since a decision has been made on what option to use, the plans will be refined before going into the final design. Construction is anticipated to start in 2018.

The estimated cost of the interchange at this time is about $16.9 million, according to the release.

Public learns about Shrewsbury interchange plans

The option was chosen over the tight diamond interchange because the diverging diamond interchange can handle heavy left-turn movements seen at the interchange more efficiently as well as improve safety, said Mike Keiser, PennDOT's District 8 executive for southcentral Pennsylvania, in the release.  He said it will function 10 years longer than the tight diamond interchange, and the interchange can be more easily expanded if the area grows faster than projections.

PennDOT hosts meeting Wednesday on plans for Shrewsbury I-83 exit

— Reach Christopher Dornblaser at