The McKees Rocks Bridge will be closed in both directions from 9 p.m. Friday to about 4 p.m. Saturday while lines are repainted.
The work is part of a project to improve traffic flow and safety at the Pittsburgh end of the bridge. The project will add a third lane to the eastbound side starting several hundred feet from the Route 65 intersection. The lane will be for those turning right to southbound Route 65.
The current yield sign for those drivers will be changed to a traffic signal, with no turns permitted on red, said PennDOT traffic engineer Todd Kravits. Other signals at the intersection and in the area will be reconfigured over the next week to speed traffic flow.
The changes are primarily intended to reduce crashes caused by drivers trying to merge into oncoming traffic as they use the right-lane ramp onto Route 65, he said.