The Traugers Crossing Road bridge in Bucks County's Nockamixon Township closed for repairs Tuesday.
Engineers decided to close the county bridge following a structural inspection by the Pennsylvania Department of Transportation.
It will remain closed for repairs for six to eight months, according to Jerry Anderson, the county's operations director.
The bridge, which spans Gallows Run, was constructed in 1893 and reconditioned in 1936
The 51-foot long, 15.5-foot wide steel Pratt Pony Truss structure is one of 115 bridges owned and maintained by the county.
Anderson said the bridge detour is very similar to the one put in place when the Kintner Road bridge was closed for repairs during October.
Emergency response personnel have been notified and instructed to use alternate routes to access the surrounding area.