Loop 360 was designated on March 29, 1962, on its current route from US 290 to US 183. On September 30, 1969, Loop 360 was extended north to Loop 1. On April 25, 1996, the section from US 183 to Loop 1 was canceled and removed from the state highway system. The south section of Loop 360 from US 290 to RM 2244 was opened on February 11, 1970. The last section of roadway for Loop 360 (excepting the bridge) between RM 2244 and FM 2222 was approved on September 30, 1976. The north and south sections of Loop 360 were connected when the
Pennybacker Bridge was opened for traffic on December 3, 1982. On February 19, 1980, the
Travis County commissioners voted to designate it the "Capital of Texas Highway". On July 14, 2004, the
Capital Area Metropolitan Planning Organization (CAMPO) changed segments of the future designation to a
toll road, despite popular outcry. However, toll conversion of the road is unfunded so plans to toll Loop 360 are delayed indefinitely and there remains substantial opposition to any toll conversion of the road from residents and environmentalists. CAMPO has begun to reexamine the toll roll designation. The road should remain tollless for at least the near future. On December 6, 2006, the
Mobility Alternatives Finance Study final report, commissioned by the City of Austin and other central Texas municipalities, noted the poor financial feasibility of toll conversion by stating "Loop 360's toll revenue funds the smallest share of its construction cost (7%)" given a construction cost of $741 million with revenue bonds backed by future tolling of Loop 360 contributing just $51.8 million (in 2006 dollars).
Historical markers There are three historical markers along Loop 360: • "The Johnson Smokehouse" marker is at the entrance to the Woods of Westlake Heights subdivision, just south of Westbank Drive. The marker commemorates the Johnson Ranch. Charles Johnson, a native of
Sweden, procured the original 124 acre (0.5 km2) ranch on the south side of present-day Loop 360 in 1867. The
smokehouse beside the marker was relocated from the original ranch house site. According to the marker, the smokehouse was painstakingly catalogued, stone by stone, disassembled and restored to its original state." The smokehouse's tin roof is built with tin salvaged from the temporary Texas capitol building, which burned down in 1899. • The "Eanes-Marshall Ranch" marker is at the Loop 360 entrance to Saint John Neumann Catholic Church. Alexander Eanes (1806–1888) acquired the property for the ranch by 1857. Alexander later sold the ranch to his brother, Robert Eanes (1805–1895) after the
Civil War. Robert sold the ranch to his son-in-law, Hudson Boatner Marshall (1862–1951) in 1883. A log cabin built on the ranch was the first Eanes school and the surrounding community assumed the Eanes name. • The "Balcones Fault Aids Colonization of Texas" historical marker is north of Bull Creek on the west side of Loop 360. It commemorates the role that the
Balcones Fault played in the Anglo-American settlement of Texas. == Route description ==