TYLin was the lead design engineer for operational, capacity, and diverging diamond interchange (DDI) improvements for SR 836 in Miami, Florida.
The new DDIs are located on the toll highway corridor in the heart of Miami, between Miami International Airport (MIA) and downtown. The project was the first implementation of the innovative DDI design concept in South Florida. TYLin provided roadway, bridge, and drainage design to enhance the highly traveled SR 386 with safety, capacity, access, and aesthetic improvements.
Completed as a design-build project for the Miami-Dade Expressway Authority, the scope of work included the design of two state-of-the-art DDIs and accompanying infrastructure modifications required to preserve Open Road Tolling (ORT). TYLin’s design services also included 31 bridges at 25 locations along the corridor and two new right-hand flyover ramps providing direct access to MIA.
The SR 386 east-west corridor serves as the city gateway for travelers arriving at MIA. The project spanned five miles of mainline expressway and included widening and full reconstruction of six urban interchanges. All work occurred under heavy commuter traffic and required right-of-way acquisitions and major utility relocations.
To address high traffic volumes at peak hours, TYLin developed explicit multi-phased Maintenance of Traffic plans that were constantly reviewed and updated based on conditions to maintain traffic. Detailed construction access to work zone plans also assured the safety of the traveling public and construction personnel.
- The DDIs significantly improve traffic efficiency and safety at the entrance and exits of the expressway.
- TYLin’s design innovations included adjustments to the alignment of the flyover bridges to reduce bridge lengths and provisions to add tolled express lanes in the future.
- New continuous through lanes, one westbound and one eastbound, and improvements at five interchanges were designed to increase traffic capacity.
- Construction of an eastbound collector-distributor road for NW 45th Avenue and NW 42nd Avenue and westbound improvements at the NW 37th Avenue interchange improve traffic flow in a highly congested urban environment.
- TYLin designed the electrical infrastructure for three new gantry tolling facilities.
- Along with improved connectivity with the rest of the Florida Expressway network, the roadway now accommodates Bus-on-Shoulder (BOS) service for Miami-Dade County’s Express Bus Service to downtown.