Florida's State Road system resulted in the removal of the SR 27 signs from US 94 and the assignment of the hidden Florida Department of Transportation designation State Road 90, which continues to be applied to the east–west stretch of highway to this day. The north-south section was assigned the designation State Road 45. In 1949, the US 94 signage was replaced with US 41 signs, over a decade after AASHO modified its guidelines to discourage short (under ) U.S. Highways that are entirely within one state. After US 94 In the 1950s, the newly configured US 41 was extended eastward and northward, first to downtown Miami along US 1 in 1950, then to Miami Beach along US 1 and SR A1A in 1953. In 1965, US 41 was rerouted as a bypass along unsigned SR 45A around Venice Gardens, while Business US 41 signs grace the former alignment (which is still named Tamiami Trail). This configuration of US 41 south of Tampa remained intact until the U.S. Highway was truncated to US 1 and Southwest Eighth Street in Miami in 2001—the historic eastern terminus of US 94, former SR 27, and current SR 90 (westbound US 41 and SR 90 now begin one block to the north, on Southwest Seventh Street, as the easternmost of the U.S. Highway now lie along a one-way pair). While US 41 and SR 90 have not significantly changed since the 1960s (aside from the widening to the east of SR 997 in Miami-Dade County in the 1970s and in 2002-2005), its importance to motorists of southeastern Florida has changed since the opening of Alligator Alley to the north in 1968. Since then, traffic on the Tamiami Trail across the Everglades has lessened significantly, while urban sections of the road are now often congested. In 1968, the Dade County Port Authority began construction on what was to become the world's largest airport. The Miami Jetport was located west of Miami, just across the Collier County line. It was to be a six-runway supersonic airport. The project would also transform the Tamiami Trail into a multi-lane expressway. Conservationists were worried about the impact an airport that size would have on the environment of the Everglades and Big Cypress. After several court hearings, a ban was placed upon further development. The widening of Tamiami Trail as a part of the Jetport had been stopped. One runway