The 39-foot-long bridge was posted for one-lane traffic following a periodic bridge inspection.
The bridge is located in Plum Township, between the intersection with Route 27 and the intersection with Williams Road.
Traffic is being channeled into one single lane in the center of the bridge and controlled by stop signs.
The bridge is a concrete T-beam structure, which was built in 1923 and is currently classified as structurally deficient. The bridge is used by about 400 vehicles a day, on average.
The bridge is due to be replaced in 2017.