The Interstate Highway begins in Sunrise as the eastern part of an interchange with Interstate 75 on the southern and western ends (I-75 "north" leads into Alligator Alley on the west side) and the Sawgrass Expressway on the northern end. For most of its length, State Road 84 (the former number for Alligator Alley) runs parallel to the highway, acting as an access road on either side of the Interstate. From the western terminus, the highway heads east to Davie, acting as a commuter route between the western fringes of the populated part of Broward County and Fort Lauderdale. At University Drive, I-595 goes below a partial stack interchange. Three miles east of that interchange, it meets with Florida's Turnpike and U.S. Highway 441. In Fort Lauderdale, I-595 intersects with I-95 at the northwestern end of the airport. At the eastern end of the airport, it has its final interchange with U.S. Highway 1 (which runs concurrently with State Road A1A at the interchange), providing access to the airport and Port Everglades. The eastern terminus consists of two lanes for US 1 southbound, two for US 1 northbound and two lanes for Port Everglades via Eller Drive. The exit for southbound US 1 has a ramp to the airport. State Road A1A is not listed on the exit signs.
Interstate 595 grew out of a highway plan for connecting Port Everglades with Alligator Alley, first conceived in 1969 as the Port Expressway. In 1974, once I-75 was rerouted to Broward County on Alligator Alley as a part of its eastern connection from Naples, it was proposed to be built as an interstate, likely as the southmost end of I-75. However, when the southern terminus of I-75 was moved from Broward to Dade County at the Palmetto Expressway/Gratigny Parkway in the late 1970s, it delayed the construction of the trans-Broward expressway.
In the early 1980s, I-595 was planned to be partially a toll highway to cover its cost of construction. By the time construction started on July 26, 1984, the tolls for the highway vanished, and it was built with only minor changes in its route. The first section, between I-75 and Hiatus Road opened in May 1988, with the section between Florida's Turnpike and US 1 opening on February 24, 1989, and the last section, connecting the disjointed sections opening on October 21, 1989. The highway was designated as I-595 on June 11, 1990, and the Rainbow Interchange with I-95 was completed on March 22, 1991, the last unfinished interchange of the original plan.
I-595 eastbound at the SR 84/US 441 interchange
The portion of the highway between I-95 and US 1 was built on top of and old set of Port Everglades Railroad tracks that went to Port Everglades.
I-595 appears to be a spur route of I-75 but Alligator Alley was not designated as I-75 until 1993. When I-595 came into existence, the only Interstate Highway that it intersected was I-95.
In 2002, I-595, along with most of Florida's interstates, switched over from a sequential exit numbering system to a mileage based exit numbering system. Numbers were changed again at about the time the express lanes were opened in spring of 2014.
The $1.8 Billion tolled SunPassexpress lanes Project in the middle of the expressway to relieve the traffic congestion opened for test use on March 26, 2014 and started tolling on April 9, 2014. The Express Lanes will significantly improve the capacity and operations of the I-595 corridor by providing three additional at-grade lanes in the median of the corridor. The lanes will reverse direction in peak travel times (eastbound in the a.m./westbound in the p.m.). To maximize the operational efficiency, the lanes will have tolls at varying rates throughout the day to optimize traffic flow, and access to and from the lanes will only be allowed west of 136th Avenue, east of U.S. 441/State Road 7, and through a direct connection to the median of Florida's Turnpike, removing long distance commuter traffic from the general purpose lanes. FDOT will retain control of the toll revenue and toll rates.