The Monongahela (Mon) River Bridge is part of the 24 mile long, Mon/Fayette Allegheny Expressway. The expressway will be a limited access highway with toll collection facilities within the limits of the facility. The expressway will be four lanes with a variable width median. However, the Mon River Bridge will carry eight lanes of traffic.

The Mon River Bridge is a mainline structure which will span the former U.S. Steel Duquesne Works, several railroad tracks and the Mon River, touching down in North Versailles Township. The Draft Environmental Impact Statement (DEIS) preliminarily defined the crossing as a three-span structure with a main span of approximately 900 feet and back spans of approximately 600 feet. Only one set of piers will be located in the river.

The objective of the Mon River Bridge Project, officially known as Section 53D, is to refine the preliminary designs presented in the Draft and Final Environmental Impact Statements (FEIS) and prepare final construction plans, specifications and cost estimates. The length of the project is approximately 2,330 feet and entirely on structure. The project has been organized into three phases: preliminary engineering, final design and post design services.

Bridge Type Studies are currently underway. Eleven bridge types are under consideration, including trusses, arches, and cable stayed structures. The main channel span length has grown to 1120 feet, in order to accommodate commercial marine operations on this section of the river.