SHREWSBURY, Pa. (WHTM) – PennDOT has started work to build a new interchange at Interstate 83 Exit 4 in southern York County, and the end result will be unlike anything drivers have ever seen in this area.
The $29.8 million project includes replacing the northbound and southbound bridges that carry I-83 over Route 851. Route 851 will be widened to four lanes and realigned into a so-called “diverging diamond” interchange.
When finished, Route 851 traffic will cross to the left side of the road at a signal before the I-83 bridge, then cross back to the right at a signal beyond the interstate. The pattern allows easier merging at the on-ramps and off-ramps.
“It really does help with the congestion and safety,” PennDOT spokesman Mike Crochunis said. “You have far fewer traffic stacking on turn lanes and through lanes, and that what we have happening at this interchange.”
PennDOT expects the project to be completed in the summer of 2021.
The project’s website at www.penndot.gov/I83Exit4 explains how a diverging diamond interchange works, shows the proposed layout of the Exit 4 interchange, and has example videos of a diverging diamond interchange in Washington, Pennsylvania.