The initial phase of the work is already under way with the installation of silt fences and other erosion-control devices. Project offices will soon appear near the highway.
The southbound lanes will be done first.
PennDot engineers have figured out how to reroute the approximately 33,000 vehicles that travel this portion of the interstate every day. Trucks represent about 35 percent of the total. The pavement on the southbound lane will be replaced this year, the northbound lane next year. The work will stop during the winter.
The northbound lanes will carry all the traffic while the southbound lane is being reconstructed. This will be done by paving the northbound shoulder. Southbound traffic will be rerouted across the median to the northbound lane, which will be separated by a concrete barrier to prevent head-on collisions.
The work to widen the northbound lanes will be done from 7 p.m. until 9 a.m. Traffic will be reduced to one lane in both directions during those hours.
Next year, the newly reconstructed southbound lanes will carry all four lanes of traffic while the northbound lanes are rebuilt.
Traffic will be maintained on all interchange ramps to and from Interstate 81 during each phase of the project construction.
According to Penney, the pavement on that section of the interstate was installed around the mid-1960s. Water has gotten into the base under the pavement and weakened it so that it moves when vehicles pass over its joints, creating the washboard effect.
Bridges carrying local roadways over I-81 at Pine Stump Road, Route 696, and Mainsville Road will also be rehabilitated, as will I-81 bridges over Wayne Avenue in Chambersburg and one spanning railroad tracks just south of the Wayne Avenue bridge.