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Route 318 ​Bridge Replacement Project

Beams are set in place for the Route 318 bridge. ​​

Project Overview

This project is to replace the bridge that carries Route 318 over Interstate 376 in Mercer County. 

The Route 318 bridge was struck by the boom of a truck traveling eastbound on I-376 the morning of December 7, 2023, and sustained substantial damage and was closed. An inspection revealed damage to three beams as well as a hole in the deck.

For the safety of traffic traveling under the bridge, it was determined the damaged portion of the bridge should be removed as soon as possible, which was completed in less than 36 hours after the crash. Route 318 has remained closed in that area. 

The project will include demolition of the remaining existing structure, construction of a new bridge, the partial reconstruction of the roadway near the bridge and the I-376 ramps, and repairs to correct damage to the interstate caused by the crash.

The new bridge will have a higher vertical clearance than the former structure but will maintain a similar alignment with the roadway. The former bridge, which was built in 1966 and was rated in fair condition prior to the crash, was posted at 14 feet, 2 inches. A new bridge will meet the current standard of 16 feet, 6 inches. 

Construction began April 15, 2024 and is expected to be completed by November 2024.

Route 318 Bridge location map.png

The bridge is located east of West Middlesex Borough and was built in 1966. Prior to the crash, it was rated in fair condition and was posted at 14 feet, 2 inches. It was used by approximately 3,200 vehicles a day, on average.

The contractor is Mekis Construction Corporation of Fenelton, PA. The contract cost is $5,145,068.12. The project is being paid for through a combination of 20 percent state and 80 percent federal emergency funds. ​​

Traffic Impacts

A detour is currently in place for Route 318 traffic due to removal of the portion over the eastbound lanes of I-376. It is posted using Route 18 and Interstate 376 and will remain in place during construction. 

Near the end of the project, short-term detours of the ramps are anticipated in order to complete reconstruction work. 

A short-term closure of the westbound lanes of Interstate 376 will be needed to remove the remaining span of the bridge. A detour will be posted using off- and on-ramps near the bridge. Otherwise, short-term lane closures on Interstate 376 may be needed for certain construction activities.

A portion of the Route 318 bridge was demolished in December 2023.

Project Updates


Drivers are reminded that the Interstate 376 eastbound ramps at Exit 1C (Route 318, West Middlesex) are expected to be closed starting June 20, 2024. 

A detour will be posted using Route 18, Route 760, and I-376. The ramps are expected to reopen in August 2024. 

The closure is needed in order to complete work on Route 318 near the bridge and the eastbound ramps from and to I-376. The work will raise the profile of the roadway to meet the higher vertical clearance of the new bridge. 

Additionally, drivers may encounter daytime lane restrictions on I-376 near the bridge, as work requires. 


​Following the completion of work on the beams, construction will start on the roadway near the bridge and the eastbound ramps.

The off and on ramps at Exit 1C will be closed starting June 20, 2024. A detour will be posted using Route 18 and Route 760. The closure is expected to remain in place until mid-September. 

Route 318 bridge rebuild


Route 318 bridge demo WB.JPG