Serving over 430,000 vehicles daily, the S.R. 826/836 Interchange in Miami-Dade County, Fla., was reconstructed with the development of an overarching “mobility plan” designed to specifically reduce the impact on traffic due to construction delays.
The Florida Department of Transportation (FDOT) spearheaded the six-year reconstruction project in conjunction with the Miami-Dade Expressway Authority (MDX), delivering impressive feats that included the completion of 45 new bridges, the expansion of 10 lanes to 28 lanes at the widest point of the interchange, stretching an original 42 lane-miles to 95.7 lane-miles, turning a two-level interchange into a five-level interchange and implementing intelligent transportation systems along the project.
The project was the last stage of a longstanding improvements project for FDOT to improve traffic flow and connections between the Palmetto Expressway/S.R. 826 and the Dolphin Expressway/S.R. 836. According to Mario Cabrera, FDOT District Six construction engineer, the project was critical to the area for freight movement and expansion of cargo operations in the area, particularly for the Port of Miami, as the area was rather notorious for stagnant traffic movement.
The challenge for FDOT’s team was figuring out how to minimize disruption while maximizing mobility during construction.
“We did a lot of traffic modeling for some of the phases to ensure that we would reduce any potential impacts to traffic,” Cabrera told Roads & Bridges. “We essentially modeled the maintenance of traffic schemes before they were implemented to ensure they would indeed improve traffic flow during construction.”
Cabrera also emphasized how the project has the potential to improve commuting for motorists in the area. “There’s a lot of commuting that occurs from the west region of Miami-Dade County to the east towards downtown and the beaches and the airport,” Cabrera said.
The traffic model implemented during construction included maintaining the same number of lanes open during peak hours for all traffic movements going westbound/eastbound and southbound/northbound.
The project was designed with collector-distributor lanes, allowing traffic to enter and exit separate from the mainline, while also connecting to it.
Ultimately, the task of reconstructing the two expressways, which originally had what Cabrera described as an “obsolete design” that dated back to the 1960s, succeeded in maintaining mobility during construction and increasing capacity and safety for future traffic.
Location: Miami-Dade County, Fla.
Owner: Florida Department of Transportation
Designer: BCC Engineering Inc.
Contractor: Community, Condotte, de Moya Joint Venture
Cost: $563 million
Length: 3 miles E-W; 2 miles S-N
Completion Date: September 2016