split from I-15) and continues south, intersecting I-80 and State Route 201 before turning east in Taylorsville, intersecting I-15 in Murray, and turning north in Holladay. From there it parallels the Wasatch Range through the affluent residential eastern suburbs before ending at I-80 at the mouth of Parley's Canyon. This belt route largely serves as a commuter route for the suburbs. The 2002 Winter Olympics prompted an urgent acceleration of the already planned massive overhaul of I-15, from 600 North in Salt Lake City to 10600 South in Sandy. The interstate was expanded to ten lanes, including two high-occupancy vehicle (HOV/express) lanes. Portions of I-80 and I-215 were also reconstructed. Since original construction, the HOV lanes have been evolved to what the Utah Department of Transportation (UDOT) refers to as Express Lanes. These Express Lanes, also known as High-occupancy toll lanes (HOT lanes) are for use by vehicles with two or more persons (including buses), motorcycles, and clean-fuel vehicles. Other vehicles can also use the lanes if they use an Express Pass. The Express Pass allows for automatic electronic toll collection. Tolls vary by distance driven in the lanes and current traffic congestion. State Route 201, known locally as the "21st South Freeway" or the "201", is a freeway that heads westward from the southern I-80/I-15 junction, known as the "Spaghetti Bowl", along the border of Salt Lake City and West Valley City. This is a largely congested route that serves much of the west side commuter traffic. As it dips southward into Magna, it is downgraded to an expressway, although it is eventually planned to be upgraded to a freeway as traffic from Tooele County increases. It continues westward to I-80 near the Tooele County line. In addition to serving the west side of the valley, SR-201 also serves as a commuter freeway for Tooele County and an alternative to I-80 when needed. Bangerter Highway (State Route 154) is an expressway that serves the quickly growing west and south sides of the valley. It begins near I-15 in Draper then heads west through Bluffdale and Riverton before heading north along the west side of the valley through South Jordan, West Jordan, West Valley City, and Salt Lake City before crossing over I-80 and ending at the Salt Lake City International Airport. Another expressway, that will eventually become a freeway, is the Mountain View Corridor (SR-85 and a section of