First Diverging Diamond Interchanges Open for the Miami-Dade Expressway Authority’s (MDX) SR 836 Toll Highway Capacity Improvements Construction Project in South Florida


T.Y. Lin International (TYLI), a globally recognized, full-service infrastructure consulting firm, announces that South Florida’s first two Diverging Diamond Interchanges (DDIs) have opened to traffic, the first on August 13, 2018, and the second on January 14, 2019. The Owner agency is the Miami-Dade Expressway Authority (MDX). TYLI served as Prime Designer for the project, providing roadway design, bridge design, and drainage design.

The new DDIs are located on the SR 836 Tolled Highway Corridor in the heart of Miami, between Miami International Airport (MIA) and downtown. The overall objectives of the SR 836 Toll Highway Capacity Improvements Construction Project are to increase safety and capacity, improve access, accommodate Bus-on-Shoulder (BOS) service, and enhance regional connectivity with the rest of the Florida Expressway network.

Other improvements include a new flyover ramp into MIA and the rental car facility at NW 42 Avenue/Le Jeune Road, as well as improved access to and from the airport, adding two missing interchange movements for NW 57 Avenue/Perimeter Road. It amounts to a very challenging project totaling five miles of mainline expressway widening and full reconstruction of six urban interchanges, requiring right-of-way acquisitions and major utility relocations, all under heavy commuter traffic.

The entire SR 836 Improvements design-build project is well advanced and approaching completion this year. The new DDIs are already “bearing fruit” with improved capacity and traffic flow at the interchanges and reduced traffic backups. Local drivers and pedestrians, while initially intimidated by the new concept, are quickly getting used to the innovative traffic pattern.