The road begins at the national southern terminus of Interstate 75 at the Palmetto Expressway at the border between Miami Lakes and Hialeah. The road heads east as an eight lane expressway through Hialeah's residential areas and through the first of two $0.47 toll gantries. Following the gantry, the expressway has its first interchange with NW 57th Avenue/Red Road, giving access to Opa-locka Airport just north of the toll road. SR 924 then curves southeast, leaving Hialeah and heading towards the second $.47 toll gantry in Opa-locka, followed by an interchange with SR 953 before the expressway ends at NW 32nd Avenue, becoming NW 119th Street, a divided surface street heading due east. The road then becomes a mix of commercial and residential areas as it crosses SR 9, then reaching North Miami, intersecting with U.S. Route 441/SR 7, followed by Interstate 95, becoming a residential street before ending at SR 909.
Tolls
The tolls on the expressway portion of SR 924 are all electronic, and does not accept cash. Payment is done either via SunPass transponders or via toll-by-plate billing, the latter of which attracts a higher cost. Two toll gantries are located along the expressway portion of the road, each charging $0.47 for SunPass users and $0.94 for Toll By Plate users. The eastern toll gantry is placed at the location of the former toll plaza which closed in 2010 when cash collection ended. As of June 8, 2018, it costs $0.94 to travel the entire expressway portion via SunPass and $1.88 via Toll By Plate. All motorists are charged at least one toll for using the road; there are no "free sections" as existed prior to the electronic toll conversion in 2010.
History
Despite appearances, the Gratigny Parkway isn’t an outgrowth of an attempt to extend I-75 to connect with I-95. Initial plans for the Gratigny were devised in the 1960s, when planners had hoped to route I-75 along the Tamiami Trail and the then-under construction "east-west Expressway" that opened as SR 836 and eventually became known as the Dolphin Expressway. When plans for the major north-south Interstate changed so it would be routed along Alligator Alley instead, the proposed Opa-locka Expressway was intended to be Miami-Dade County's second full east-west throughway. The Opa-locka Expressway was never intended to terminate at I-95, but merge with a surface street within a few blocks of it instead. Funding issues caused the Florida Department of Transportation to mothball its construction plans for over a decade, but when the plan was revived, the changing demographics of the neighborhoods impacted by construction. In 1982, racial politics killed the portion of the Opa-locka Expressway that was planned for east of Northwest 32nd Avenue, and the proposed new expressway received a new name: the Gratigny Parkway. Faced with rising construction costs in 1982, FDOT officials told the North DadeChamber of Commerce that the Gratigny Parkway would be built as a toll road; and in the following year, the construction project was given a green light. In 1984, increased opposition almost derailed construction of the expressway again, but this time the resistance came from residents of Miami Lakes and Hialeah. Both communities didn't want any expressways to be built, even to the point of Hialeah amending its city charter to oppose all expressway construction within its city limits. Yet at that point, FDOT had already purchased 90% of the land needed for construction of the Gratigny Parkway - and it was determined to get it built. After a compromise that deleted one interchange with a major surface street, construction finally began in 1987. The Gratigny Parkway opened to traffic in January 1992. At the time, no signs indicated the name of the toll road: they merely showed the SR 924 designation that it shared with Gratigny Road to the east. In 1997, the newly established Miami-Dade Expressway Authority took over the operation from FDOT. New TOLL shields made their appearance along the expressway but not the surface road to the east of 32nd Ave; the corner of Northwest 119th Street at 32nd Ave has an MDX "end 924" sign for the eastbound drivers, while on the other side of 32nd Ave an FDOT "east SR 924" sign greets people who wish to continue eastward on the surface street. In 1998, the expressway section of SR 924 was designated as the Marlins Expressway by the state of Florida to honor the Florida Marlins' 1997 World Series victory. On June 7, 2010, the tolled section of SR 924 ceased collecting cash tolls and went completely electronic, with SunPass users paying the same rate as before, but those without SunPass have to utilize the toll-by-plate program, which adds a 15 cent surcharge to every gantry they pass. By 2014, the cost to drive on the expressway is double on the Toll By Plate system compared to SunPass.
