Proposed commuter rail in the Phoenix metropolitan area  There is a current proposal to bring commuter rail service to the Phoenix, Arizona metropolitan area. The Arizona Department of Transportation is also currently studying a proposal to create inter-city rail between Tucson and Phoenix, with a corridor along the current I-10 highway. This project is known as the Arizona Passenger Rail Corridor Study (APRCS). Daily rail service had existed until the 1960s between Phoenix, Glendale, and Wickenburg as well as Tempe and Mesa. Contemporary discussion of commuter rail in Phoenix began with the "Hattie B." flood relief train of 1980, and was first widely promoted in 1991 by the Arizona Rail Passenger Association with the release of its Arizona Rail report. The Maricopa Association of Governments (MAG) and the Arizona Department of Transportation are studying suburban commuter rail as a complement to light rail. The MAG Commuter Rail Strategic Plan was released in March 2008. In April 2008, a coalition of Arizona business and political leaders, including then-Governor Janet Napolitano, proposed a $42 billion state transit plan which would include commuter rail. Commuter rail would run along upgraded existing freight rail lines, with stations every three to five miles (8 km). In Phoenix, as in other areas that have implemented commuter rail, track speeds would be increased, signals updated, and additional sidings and double-track added. In October 2018, MAG issued an update to the 2010 study. This update removed the Chandler Corridor from a proposed commuter rail system, as it would have competed with San Tan Corridor Line for ridership. The Kyrene Line Corridor was also extended from its 2010-proposed terminus in West Chandler. The 2018 update includes four rail corridors which would be operated with two services. The Grand/Kyrene Line would utilize the Grand Line Corridor, traveling from Wittmann southeast towards Phoenix, and then continuing south on the Kyrene Line Corridor to Chandler, traveling in 66-73 minutes. The Estrella/San Tan Line would use the Estrella Line Corridor, traveling from Buckeye east into Phoenix, and then continuing southeast along the San Tan Line Corridor to Queen Creek, traveling in 74-82 minutes. The lines would overlap at four central stations: State Capital, Phoenix, Sky Harbor Airport, and Tempe. Provisions for extensions would allow for an additional Grand Avenue Corridor station in Wickenburg, two additional stations on the San Tan Line Corridor in San Tan Valley and Florence, and an extension of Estrella Line service to Arlington. Services would run at 30-minute headways during peak hours and 2-hour headways during off-peak hours.