All five expressways are all electronic toll roads, requiring the use of SunPass or a "toll-by-plate" program and does not accept cash, and the free movement sections were removed.

Since then, MDX has completed projects both independently and in collaboration with FDOT most notably the western expansion on the Dolphin Expressway in 2004 and the Dolphin–Palmetto Interchange in 2009.

Instead of the green "MILE XX" markers commonly seen on Interstate Highways, the five GMX expressways use blue mileage markers featuring (from top to bottom, in white): a single letter indicating the direction of travel, the State Road designation of the highway (complete with outline of the State of Florida), and two numbers separated by a horizontal line ("2" on the top, "4" on the bottom of the line represents Mile Marker 2.4 from either the southern or western end of the expressway).

SR 836, locally known as the Dolphin Expressway, is a 13.8-mile-long (22.2 km) toll road currently extending from Southwest 137th Avenue in the west to I-95 in the east.

SR 924, locally known as Gratigny Parkway, is a 5.2-mile-long (8.4 km) limited access all-electronic toll road running east to west.

The Gratigny Parkway starts east of the Palmetto Expressway/I-75 interchange in Hialeah and ends at Northwest 32nd Avenue in North Miami.