A $22 million project to replace a bridge spanning the Lehigh River in Jim Thorpe won't compromise historical sites, Carbon Commissioners said Thursday.

The Delaware & Lehigh National Heritage Corridor is concerned the project, expected to begin in 2012 and take about 2 1/2 years to complete, may damage such historical sites as a locktender's house foundation and Lock No. 1. Further, the Lehigh Canal and towpath, built in the 1800s to move coal to Philadelphia to fuel factories, runs parallel to the river.

The new bridge will be close to the Old Mauch Chunk Historic District, Lehigh Gorge State Park, the D&L Trail and the National Register of Historic Places-eligible Center Street Historic District.

National Heritage Corridor Vice President Elissa Thorne in a Jan. 26 email message to the state Department of Transportation, asked that the organization be involved in the project to ensure that historical sites will remain safe, and that the project will be done in a manner that will enhance the historic aspects of the area.

PennDOT plans the next in a series of public meetings on the project at 1:30 p.m. Feb. 9 at Memorial Hall in Jim Thorpe.

Among the Heritage Corridor's suggestions are that signs depicting historic sites along the new bridge's pedestrian walkway be installed; that the design be "context-sensitive" relative to lighting, sidewalks, retaining walls and surface textures and colors; that a single, 8-foot-wide multiuse walk/bikeway be included across the new bridge and into the downtown historic district; that there be access to the Carbon County section of the D&L Trail; and that Americans with Disabilities Act compliant pedestrian crossings be built at all associated intersections on the east and west sides of the river.

The project will replace the deteriorating Route 903 bridge, which connects routes 209 and 903, the east and west sides of the borough and links the historic and shopping district with recreational activities.

The bridge, built in the 1950s, spans the river, canal and two active railroads. There are also gas lines that run under it.

It carries about 8,100 vehicles a day over two 13-foot lanes. A 5-foot wide sidewalk is on the downstream side of the bridge.

The bridge has severe structural issues, according to a PennDOT report. The western pier has "severe deterioration and instability; a temporary steel pier was installed to provide additional support."

The "deck and concrete encasements are deteriorating and require significant maintenance to remain functional," the report states. "In addition, there has been movement of the bridge at the eastern abutment," it says.

Due to road configuration, there is frequently traffic congestion at the bridge.

Engineering work began in 2002, and it was determined the new bridge should be farther upstream from the current span. The existing bridge will be demolished after the new one is built.

"The game plan, as we understand it, is to cross at the North Street extension, coming down Route 903 and coming straight across," said Commissioners Chairman William O'Gurek.

He said the county has met with PennDOT a number of times to discuss the Heritage Corridor's concerns, and that the county "recently signed off on a letter stating that we recognize that (the project) is in a historic district and there are historic resources."

He said those resources, the Trail, for example, may be temporarily disrupted.

"We recognize there will be a temporary interruption, but everything will be fully restored," O'Gurek said.