I-4 maintains a diagonal, northeast-southwest route for much of its entire length. Throughout most of Orange County and Seminole County, I-4 travels in a roughly north-south direction.
The route begins with an interchange with I-275 in the Tampa, St. Petersburg area and continues east toward I-75. At this point, the interstate starts a turn toward the northeast where it intersects with the Orlando area cutting the city through at a diagonal direction going northeast/southwest. The route provides access to all of Orlando's theme parks including Disney World and Universal Studios. Right before the eastern terminus, I-4 switches to a mostly east/west route in order to connect with traffic from and to I-95.
At an interchange with I-95 in Daytona Beach, I-4 terminates; however, SR 400 continues eastward into Daytona Beach. This highway eventually reaches Daytona International Airport and Daytona International Speedway.
SR 400, unsigned while concurrent with I-4, becomes signed east of I-95. The road extends for three miles from the northeast terminus of I-4 to an intersection with U.S. Route 1 (SR 5) in Daytona Beach. Named Beville Road, it runs along the boundary between Daytona Beach and South Daytona.