Loop 363 starts at Interstate 35 (I-35, General Bruce Drive) in the northern part of Temple. The highway travels in a southeast direction from here through sparsely populated areas of the city, traveling close to the eastern border of the city limits. Loop 363 has an interchange with State Highway 53 (SH 53, Adams Avenue) near Hector P. Garcia Elementary, before slightly turning in a southwest direction. Shortly after the interchange with SH 53, the highway has another interchange with Avenue H/Little Flock Road. Loop 363 junctions with U.S. Highway 190 (US 190)/SH 36 and SH 95, beginning an overlap with US 190/SH 36. At Spur 290 (1st Street), the highway runs as a freeway. The freeway section of Loop 363 runs through a heavily developed area in the city's southside. At the interchange with I-35, US 190 leaves the highway and 363 runs in a northward direction. Loop 363 then has interchanges with Farm to Market Road 2305 (FM 2305, Adams Avenue) and Airport Road. This is the western terminus of SH 53 and the end of the concurrency with SH 36 which continues to the northwest. After this interchange, the highway runs through sparsely populated areas of the city again. After the intersection with Industrial Boulevard, Loop 363 turns back to the east and runs by a Walmart distribution center and the main Wilsonart plant, before running back to I-35. The stretch between Airport Road and I-35 is under construction as of 2015, varying between freeway grade and unlimited divided highway. This is expected to be completed entirely at freeway grade in 2017.
Loop 363 was designated on June 26, 1962, running from I-35 to US 190. On July 30, 1965, Loop 363 extended northwestward from I-35 to SH 36. On January 31, 1967, Loop 363 extended eastward concurrent with US 190 and northward to I-35. On February 25, 1987, Loop 363 extended from I-35 to SH 36, completing its current route.