Prep work started on Tuesday night and will continue through the fall for the Interstate 81 widening and improvement project between I-81 Exit 57 (Route 114/Mechanicsburg) and Exit 59 (Route 581) in Cumberland County.

For drivers, this means that traffic may be restricted to a single lane in one or both directions during the overnight hours between 9 p.m. and 6 a.m.

Over the next month, construction work at night will build up and strengthen the northbound and southbound shoulders of the interstate. A temporary on-ramp will also be built between Route 114 and northbound I-81.

This is in preparation for carrying vehicles when traffic patterns are shifted next year to accommodate the major construction work in the median area. In addition, six emergency pull-off areas will be built – three in each direction – in preparation for next year’s traffic shift.

Other work this fall includes repairs to the northbound and southbound bridges that carry I-81 over Lambs Gap Road. This should not affect interstate traffic because the work will focus on the piers and abutments under the bridge deck.

The contractor will also be clearing trees and shrubs along the right-of-way in preparation for installing new right-of-way fencing and drilling for the foundations of sound barriers along a portion of southbound I-81.

PennDOT has contracted with Blooming Glen Contractors of Blooming Glen, Pa., for $19.5 million to widen this section of I-81.The project involves extending the northbound on-ramp as an auxiliary ramp between the two interchanges and extending the westbound ramp from Route 581 along southbound I-81 to the interchange with Route 114.

The traffic shift scheduled for next year will enable the contractor to build the additional ramp in each direction mainly in the median area. Cable median barrier will also be installed as part of the project. The entire project should be completed by the end of May 2018.