Bridge and tunnel work to start in summer

Keith Wargo, the authority’s assistant general manager for engineering and technical support, said the contractor will divide the bridge into four quadrants and work on one section at a time to reduce disruptions.

Traffic will be reduced to one alternating lane during construction, but, because crews will work on only about 800 feet at a time in one lane, the work shouldn’t cause serious bus delays, he said.

The work will include expansion joint replacement, painting, substructure repairs and applying an epoxy-based coating on the concrete deck.

As far as the light-rail tunnels are concerned, work will be done overnight beginning at about 8 p.m., with transit cars using one tunnel to avoid any rushhour disruptions.

The twin 2,900-foot tunnels are on the system’s red line between Raleigh Avenue at McFarland Road in Dormont and Shady Drive near Washington Road in Mt. Lebanon.

Mr. Wargo said this project will involve injecting grout into the arched ceiling of the tunnels to seal cracks and prevent water from causing problems as a result of freezing during cold weather or erosion in warm weather. The committee recommended awarding the contract to Mosites Construction of Robinson.

Both projects should begin this summer and be completed in a little more than a year.