State Roads in Florida
Standard (left) and toll (right) State Road shields
|Notes:||State Roads are generally state-maintained.|
|Interstates:||Interstate X (I-X)|
|US Routes:||U.S. Highway X (US X)|
|State:||State Road X (SR X)|
State Roads are always numbered; in general, the numbers follow a grid. Odd numbered roads run north-south, and even numbered roads run east-west. One- and two-digit numbers run in order from 2 in the north to 94 in the south, and A1A (formerly 1) in the east to 97 in the west (99 used to exist but is now a county road). The major cross-state roads end in 0 and 5.
Most routes of the form X00 are major diagonal routes; an even first digit indicates a southwest-to-northeast direction, and an odd first digit indicates a northwest-to-southeast direction.
Other three-digit numbers are placed in horizontal bands based on the first digit:
|1||north of 10|
|2||between 10 and 20|
|3||between 20 and 40|
|4||between 40 and 50|
|5||between 50 and 60|
|6||between 60 and 70|
|7||between 70 and 80|
|8||between 80 and 90|
|9||south of 90|
When the grid was first laid out in 1945, the rules were almost perfectly followed. However, over the years, as routes have been added, there has not always been room to follow the grid. Placements such as 112 (in the 8 band), 752 (in the 2 band), and 602 (in the 1 band) are the most notable violations of the grid system. The Pensacola area has a collection of these "misplaced" street numbers. When FDOT added route numbers to a collection of Miami-Dade County streets in 1980, most of them received 9## designations regardless of the band that they occupied.
Every section of U.S. Highway and Interstate Highway has a State Road number assigned to it, usually unsigned (for example, Interstate 4 is also unsigned SR 400). In addition to some named toll roads (for example, 91 and 821, which make up Florida's Turnpike) some minor State Roads are also unsigned (like SR 913 and SR 5054).
Prior to the 1945 renumbering, State Roads were given numbers in the order they were added to the system. The 1945 renumbering removed many roads that were never built and added some that had not existed prior to 1945.
In 1955, the Florida Department of Transportation slowed down the addition of new state roads and began to classify roads into primary, secondary, and local roads. Primary roads would continue to be state-maintained, while Secondary roads would have an S before the number, and would only be state-maintained during a construction project. Local roads would be completely removed from the system.
In 1977, FDOT changed the division of roads into state/county/local. Most secondary roads and some primary roads were given to the counties, and occasionally a new state road was taken over; some main roads in incorporated areas were given to the localities.
The secondary signs had the S changed to C (for county) and a small COUNTY sticker added to the bottom. As signs grew old, they were replaced with the standard MUTCD county road pentagon. While this occurred throughout the State of Florida, the part of the state south of SR 70 was hit particularly hard by the transition from State to County control and maintenance.
In the early 1980s several state roads were renumbered; in the latter half of the 1990s, budget cuts and other factors prompted a series of truncations of several state roads, primarily in urban areas and the Space Coast and the Treasure Coast. The trend seems to have been reversed since 2002 as new state road designations have been added as a result of construction of new highways, most notably in the Jacksonville, Orlando, and the Tampa-St. Petersburg metropolitan areas.
"Interrupted" State Roads 
While most State Roads are contiguous, there is a relative handful of routes that have interruptions in their designations.
- The most famous of the set is SR A1A, which exists in seven separate pieces along the Atlantic coast from Fernandina Beach to Key West.
- State Road 2 has two sections separated by the State of Georgia. The western segment extends westward from Georgia 91 as it crosses the Chattahoochee River and has its western terminus at SR 81 near Sweet Gum Head; the eastern segment crosses the Okefenokee Swamp to connect separated segments of Georgia 94.
- State Road 15 has two sections bridged by County Road 15 and US 192/441. With the exception of a small section in the Orlando area, SR 15 is unsigned for its entire route since it is just an administrative FDOT designation for US 441 south of Holopaw, US 17 between Orlando and Jacksonville, and US 1/23 north of Jacksonville.
- The two separate sections of SR 17 formed when US 27 was rerouted in Highlands County, where it passes through Avon Park and Sebring, and in Polk County, from Haines City to Frostproof. Originally signed Alternate US 27, it is now signed as just SR 17.
- State Road 54 has a gap in eastern Pasco County, between the western terminus of State Road 56 and Bruce B. Downs Boulevard in Wesley Chapel. It also contains a former segment between 301 in Zephyrhills and US 98 in Polk County.
- State Road 78 spanned southwestern Florida from the northern tip of Lake Okeechobee to US 41 on the Gulf Coast, but during the late 1970s, the FDOT attached an S-prefix on the designation of the section between SR 29 and SR 31... and started a process that converted the segment into County Road 78 connecting the remaining pieces of SR 78.
- Until 1993, State Road 84 traversed the state from the Atlantic Coast to the Gulf Coast. When the upgraded Alligator Alley became part of Interstate 75, the unsigned FDOT designation of SR 93 was applied to the toll road, and the end pieces of SR 84 retained their number — and their signs. SR 84 is also a pair of frontage roads that run parallel to I - 75 and I - 595 from the West Arvida Parkway exit to just west of Florida's Turnpike, with a short gap before the eastern end piece emerges from I - 595 as its own road east of US 441.
- In the Jacksonville area, SR 115 travels along Southside Boulevard north from U.S. 1, and then it follows a pair of Alternate U.S. Highways, US 1 Alt. and US 90 Alt. to Interstate 95 (the hidden SR 9), where the southern segment of SR 115 ends. Three miles to the north on I - 95 is a second section of SR 115, extending to U.S. 23 near Callahan.
- There are two separate roads in Okaloosa County with the SR 189 designation: a bypass around Fort Walton Beach and a road going from Baker to the State of Alabama.
- Two sections of SR 811, both of which run roughly parallel to U.S. 1, are found in Fort Lauderdale and near Palm Beach Gardens and Jupiter.
- At one time, SR 865 extended from Estero Island (near Fort Myers Beach) to Tice. Today, SR 865 consists of two separate sections (one running north-south and the other eunning east-west) connected by a stretch of a county road that was originally part of SR 865.
- State Road 909, also known as West Dixie Highway to the residents of North Miami, has a two-block-long gap, where drivers are greeted with signs saying "TO West Dixie Hwy/TO 909" while they drive a short stretch of Northeast 125th Street (SR 922) connecting the two pieces.
See also 
- 1945 Florida State Road renumbering
- Pre-1945 Florida State Roads
- Former State Roads in Florida
- State Roads in the Florida Keys
- List of State Roads in Florida
- List of toll roads in Florida
- Florida Department of Transportation
- US Department of Transportation: Active FHWA Toll Facility Agreements
- Florida Highway Patrol State Road Listings by Troop
- Unofficial Florida route log
- AARoads Florida Highways Page
- Florida Highways Page