State Road 400 (Florida)

Interstate 4
Route information
Maintained by FDOT
Length:	132.298 mi (212.913 km)
Existed:	1959 – present
Major junctions
West end:	I-275 in Tampa
	US 41 in Tampa US 92 / US 301 near Riverview I-75 near Brandon US 98 in Lakeland US 192 in Celebration Turnpike in Orlando US 17 / US 92 / US 441 in Orlando US 17 / US 92 / SR 50 in Orlando US 17 / US 92 near Sanford US 92 in Daytona Beach
East end:	I-95 / SR 400 in Daytona Beach
Location
Counties:	Hillsborough, Polk, Osceola, Orange, Seminole, Volusia
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future Florida State Highway System Interstate US SR Former Pre-1945 Toll Scenic ← SR 3 SR 4 → ← SR 399 SR 400 SR 401 →

State Road 400
Location:	Tampa–Daytona Beach
Length:	136.514 mi (219.698 km)

Interstate 4 (I-4) is an intrastate Interstate Highway in Florida, maintained by the Florida Department of Transportation (FDOT). Spanning approximately 133 miles (214 km) along a southwest–northeast axis, it is entirely concurrent with State Road 400 (SR 400). They begin at an interchange with I-275 in Tampa in the west; in the east, I-4 ends at an interchange with I-95 in Daytona Beach, while SR 400 continues for roughly another 4 miles (6.4 km) and ends at an interchange with U.S. Highway 1 (US 1) on the city line between Daytona Beach and South Daytona. I-4 intersects with expressways including US 92 and US 17 in multiple junctions, and I-75. Unlike the other three primary Interstate Highways in Florida (I-10, I-75, and I-95), I-4 lacks an auxiliary Interstate Highway.

The first segment of I-4, from Plant City to Lakeland, opened in 1959; construction of the entire highway was completed in 1965. Its original western terminus was located in St. Petersburg, although the section of highway from St. Petersburg to its current terminus in Tampa was redesignated as I-75 in 1971, before later being redesignated again as I-275. The median of I-4 between Tampa and Orlando was the planned route of a high-speed rail line, which was ultimately cancelled in 2011. Presently, the 21-mile (34 km) stretch of I-4 extending from Kirkman Road in Orlando to SR 434 in Longwood is under redevelopment through the "I-4 Ultimate" project, which will see the addition of four variable-toll express lanes and several redesigned bridges and interchanges. From a political standpoint, the "I-4 corridor" is a strategic region given the large number of undecided voters in a large swing state.

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Wikipedia