After four days of overnight preparation work this week, the Smithfield Street Bridge will be closed to most vehicular traffic this weekend.

The bridge, which joins Station Square on Pittsburgh’s South Side with Fort Pitt Boulevard, Downtown, will be closed from 10 p.m. Friday through 6 a.m. Monday. Regular cars and trucks will be prohibited on the bridge, but Pittsburgh Regional Transit buses and emergency vehicles will still be allowed to use it, and the sidewalks will remain open.

During the closure, crews for Advantage Steel and Construction LLC will be working on roadway, median and sidewalk repairs, a bridge deck overlay and line painting on the historic bridge. That is part of an $8.5 million preservation project that began in September 2022 and should be finished this summer.

The proposed detour from the Pennsylvania Department of Transportation recommends motorists turn left from East Carson Street onto South Tenth Street and cross the Philip Murray Bridge, turn left on Second Avenue, left on B Street, right on First Avenue, left on Grant Street and right on Fort Pitt Boulevard.

Drivers coming from Downtown should follow the detour in reverse.

There should be at least one more weekend closure before the project is finished.

The full project includes steel repairs, replacing the epoxy deck surface on the entire bridge and sidewalks on two of the four bridge spans, and installing new lane controls on the bridge and a pedestrian crossing signal at the Fort Pitt Boulevard intersection.

Because the bridge’s two 360-foot truss spans are the longest remaining such spans in the country, the bridge is listed as a National Historic Landmark. It was designed by Gustav Lindenthal and built in 1883 as one of the first bridges to use steel in its trusses instead of wrought iron, according to historicbridges.org.

Ed covers transportation at the Pittsburgh Post-Gazette, but he's currently on strike. Email him at eblazina@unionprogress.com.

Ed Blazina

Ed covers transportation at the Pittsburgh Post-Gazette, but he's currently on strike. Email him at eblazina@unionprogress.com.