The 1,051-foot-long steel truss bridge that carries Route 62 over the Allegheny River in Forest County is classified as structurally deficient and plans are in place to replace it with a new 1,124-foot four-span steel grider bridge.
The plans call for the new bridge to be 100 feet upstream and to tie the road into the new bridge, as well as removing the existing bridge.
After bids are opened Thursday, construction is expected to occur later this year and into next year.
Pennsylvania Department of Transportation district 1 press officer Jim Carroll said the hope is to focus on the bridge abutments and access roads this year before much of the actual bridge construction work will begin in 2017.
The bridge project has some significant environmental barriers to overcome and chief among them is the location of the largest concentration of two species of endangered mussels in the country.
Caroll said a contractor started working last year to gather and relocate the endangreed mussels in the area that will be impacted by construction.
As many as 85,000 mussels must be salvaged from the area and they will be relocated to streams in Illionois, Indiana, Ohio, New York, Kentucky, West Virginia, elsewhere in Pennsylvania and in the Seneca Nation in Salmanaca.