Why a Skewed Arch Bridge?

From 1834 to 1854 the Portage Railroad passed beneath the Skew Arch Bridge. The original hand hewn stone bridge was built at right angles to the railroad, but a right angle turn was arduous for a wagon to negotiate, so the bridge was turned, or skewed, to make the crossing compatible. That compromise lasted for the twenty years the portage railroad operated. The bridge’s continued existence shows that new transportation systems can accommodate old ones even as one slowly replaces the other. The roadway of old US Route 22 bends to accommodate the bridge because highway engineers changed their plans in order to conserve it.

Tunnelhill, Pennsylvania · United States