In the 1960s,
Tamiami Trail was becoming insufficient to handle the rapidly growing traffic between Tampa and South Florida, and adding lanes to the road that was once considered a major engineering feat was not feasible in light of the demands of nearby
Everglades National Park and the
Miccosukee Tribe living near the Trail. It was finally decided that a second transpeninsular road would be best to serve the need of motorists to go from “coast to coast” south of
Lake Okeechobee, the new one featuring a toll
limited access two-lane expressway, the "Everglades Parkway" (the original name of the road that became better known as “Alligator Alley”). Construction began on Alligator Alley in the early 1960s. On the Naples side, the route would connect with Davis Boulevard, which was previously a local road running from US 41 to Airport Road (
CR 31). Davis Boulevard was named for George Davis, one of the Naples area's first attorneys who built one of the first houses along the road near Shadowlawn Drive. Maps in the late 1960s indicated that Alligator Alley would be designated State Road 838, a designation which runs along
Sunrise Boulevard in
Fort Lauderdale. Though, when the highway was completed and opened on February 11, 1968, the State Road 84 designation and signs were placed along the entire length of the road () from Naples to Fort Lauderdale. Two decades later, the southern extension of Interstate 75 from
Tampa was moving forward with earnest, as was the construction of Interstate 595. Because the population and traffic of southern Broward County were growing at a fast rate, Interstate 595 was being built to improve the connections between the Alley and US 1 (and improve access to
Port Everglades and
Fort Lauderdale-Hollywood International Airport), and the eastbound lanes of SR 84 were shifted southward to accommodate the new expressway that runs down what once was a large grassy median with limited cross-overs/turnarounds for SR 84. I-595 was opened to traffic in the mid-1980s. When four-laning of Alligator Alley was completed to Interstate highway and environmental standards (several tunnels were constructed at various points under the road for the
critically endangered Florida Panther), signs along the
toll road identifying it as SR 84 were removed, and I-75 signs went up to replace them in early 1993. While the SR 84 could have remained the hidden designation of the road, the
Florida Department of Transportation decided to supersede it with the hidden designation already in place for I-75 in most of the state:
SR 93. This created the disconnection of SR 84 that exists to the present day. ==Major intersections==