Florida State Road 45

A major north–south highway extending almost the entire length of the Florida peninsula, State Road 45 (SR 45) is the unsigned Florida Department of Transportation designation of most of the current U.S. Route 41 in Florida. The southern terminus of SR 45 is an intersection with SR 90 in downtown Naples; the northern terminus is an intersection with US 441 (SR 25) in High Springs. South of Causeway Boulevard (SR 676) near Tampa, SR 45 is also known as the Tamiami Trail.

South and east of Naples, US 41 turns eastward as SR 90 as the Tamiami Trail crosses the Everglades on its way to Miami; north of High Springs, US 41 overlaps US 441 (SR 25) until their split in Lake City (from there US 41 continues to the Georgia border with the hidden SR 25 designation).

SR 45 away from US 41

 * Business US 41 - Venice
 * Business US 41 - Bradenton to Memphis
 * Business US 41 (historic US 541) - Rockport to Ybor City
 * SR 60 - Tampa to Ybor City
 * SR 45 (not overlapped between Adamo Drive/SR 60 and Hillsborough Avenue/US 41-92-SR 600) - Tampa

US 41 away from SR 45

 * SR 45A - Venice
 * US 301 - Bradenton, concurrent with SR 55
 * SR 55 - Bradenton to Memphis
 * SR 599 - Rockport to Tampa
 * US 92 (SR 600) - Tampa

Additional concurrencies with SR 45

 * SR 45-55 - Memphis
 * US 41/SR 45-60 - Ybor City
 * US 41/SR 45-700 - Brooksville
 * US 41/SR 44-45 - Inverness
 * Alt US 27-US 41/SR 45-500 - Williston
 * US 27-US 41/SR 45 - Williston to High Springs

State Road 45A
State Road 45A (SR 45A) is the Venice Bypass, a segment along U.S. Route 41 (US 41) east of the Tamiami Trail in Venice, which was originally part of US 41 until 1965 when that segment was redesignated as US 41 Bus after the Intracoastal Waterway (ICW) was dredged through Venice by the U.S. Army Corps of Engineers in 1964. The route begins near Shamrock Boulevard in Venice Gardens and terminates at Venetia Bay Boulevard in the Eastgate section of Venice.