360 was designated on November 30, 1955, from SH 183 south to US 80 (now SH 180). SH 360 was extended south in various stages, first to Spur 303 on July 25, 1960, I-20 on July 30, 1965, US 287 on June 10, 1966, and US 67 on August 26, 1969. SH 360 was extended north from SH 183 to SH 121 on May 6, 1969. For the most part, each section's frontage roads were built first, handling all of the traffic years before the actual freeway portion was completed (or even begun). Similarly, the interchanges at I-20, I-30, and SH 183 were in place long before the freeway lanes were completed. The indirect interchange between SH 360 and I-30 is a relic back from when I-30 existed as the Dallas/Fort Worth Turnpike. In order to direct traffic through toll booths, the interchange was designed so that any traffic moving from between the freeways were routed through one common, bi-directional ramp. This was done as a cost-saving measure, as it required fewer toll booths. The toll booths were removed in 1977, but the complex access road system remained. South of SH 183, SH 360 was previously known as Watson Road. The segment through Arlington is also officially designated as the "Angus G. Wynne Freeway" (after the founder of Six Flags); however, neither the official designation nor the older Watson Road name are locally used, and the road is generally called "360". 360 Tollway The southernmost segment of SH 360 between US 287 in Mansfield and Camp Wisdom Road/Sublett Road in Grand Prairie was built between 1994 and 2003 as a pair of separated frontage roads, with space reserved between them for main freeway lanes to be added to meet future traffic needs. As traffic along the corridor grew, the SH 360 frontage lanes became increasingly congested. Local and state leaders began studying the construction of SH 360 as a freeway between the existing frontage roads in a project that became known as "360 South". On January 25, 2013, TxDOT and the NTTA approved a deal to construct the extension as a four-lane toll road, the 360 Tollway, in a public–public partnership, with TxDOT performing the design and construction and the NTTA managing the completed freeway as part of its tollway system. Construction on the tollway began in November 2015. A ceremonial groundbreaking for construction of the 360 South toll road