PennDOT will close one lane in both directions this weekend on the Liberty Bridge.
The restrictions will be in place from 10 p.m. Friday to 6 a.m. Monday. A contractor will remove sections of pavement to investigate the condition of the deck structure.
Transit riders also will face restrictions this weekend, as the Great Race on Sunday causes detours of more than 30 bus routes from early morning to early afternoon.
Construction will cause a detour on the Red Line, with trains rerouted to the Blue Line and rail shuttles and shuttle buses serving Red Line stops between Castle Shannon and South Hills Junction.
The rail detour is to allow replacement of the grade crossing on Dormont Avenue. It will be in effect from 7 p.m. Friday through the end of service on Sunday.
The Squirrel Hill Tunnels will remain open this weekend.
Jon Schmitz: firstname.lastname@example.org, 412-263-1868 and on Twitter @pgtraffic.