MonFayette Expressway over the Monongahela River
Duquesne, PA
The MonFayette Expressway is a new 26 mile long urban toll road being built by the Pennsylvania Turnpike Commission that will connect the formerly industrial areas of the Monongahela Valley with Pittsburgh, the Penn-Lincoln Parkway and the Pennsylvania Turnpike. The MonFayette crosses the Monongahela River near Duquesne and on dual 4 lane bridges. This valley was the cradle of America's steel industry. The site's surroundings include the Edgar Thompson Works of the U. S. Steel Corporation, a dam and lock, railroad yards and bridges, the now vacant brownfield locations of several now dismantled steel works, the wooded hillsides of the river valley and the thrill rides of the Kennywood Amusement Park.
The Expressway will cross the river at a 30 degree skew angle. That and the maneuvering space that the numerous barges require as they approaches the lock mean that the bridges must have 1100 foot long spans. Truss, arch and cable stayed bridges were considered. The cable stayed bridges ranked best in performance, cost and appearance. Based on concern about the effect of the skew angle on river flow the tower bases were made hexagonal in plan in order to llow water to flow more smoothly around them. The upper parts of the towers extend that basic shape vertically.
Because of financing difficulties after the 2008 recession the project was placed on hold. It is now being revived as a single bridge with fewer lanes.