Construction crews will begin removing the Lowther Street bridge over Interstate 83 in Lemoyne on Saturday.
Weather permitting, drivers should expect a traffic shift and single-lane traffic restrictions in each direction after 9 p.m., followed by a six-hour overnight detour starting around 11 p.m., according to PennDOT spokesman Mike Crochunis.
The detour will be in place until 5 a.m. Sunday morning, but the lane restrictions may remain in place until 6 a.m. for the removal of barricades and signs, Crochunis said.
I-83 North will be directed off at Brandt Avenue, turn right onto Lowther Street through Lemoyne back to I-83 North. I-83 North traffic headed to Route 581 West will also follow Brandt Avenue to Lowther Street and continue on I-83 North across the Susquehanna River into Harrisburg and be directed off at Exit 44-A for 13th Street to I-83 South back across the Susquehanna River to Route 581 West.
I-83 South will be directed off at Exit 42 for Lemoyne, follow Lowther Street over the interstate, turn left at 10th Street and back to I-83 South.
Route 581 East traffic headed to I-83 South will be directed to I-83 North to Exit 41-B for Highland Park, turn right onto Lowther Street through Lemoyne over the interstate and turn left at 10th Street to I-83 South.
A temporary bridge was put in place last month to carry Lowther Street over I-83 while the existing bridge is demolished and a new bridge is built. The new bridge will be large enough for four lanes of traffic on I-83 as well as three ramps.
PennDOT said the existing bridge is a major contributing factor to the bottleneck on I-83 North approaching Harrisburg and Route 581 West. The interstate cannot be widened until the bridge is removed.
Work on the new Lowther Street bridge is expected to be completed by the end of May 2013.