are doubled in construction zones and designated safety corridors, with signs often stating this. There are no longer night speed limits, nor are there any differential speed limits for heavy trucks. There are two other statutory speed limits in New Mexico that are often altered, especially on urban arterials or even city or countywide: thirty miles per hour in a "business or residence district" and fifteen miles per hour near schools at certain times. For example, in Albuquerque the default speed limit is thirty miles per hour as per state law, but many streets have a different speed limit. Some school zones there have twenty miles per hour speed limits. The city of Santa Fe's default speed limit is twenty five miles per hour. Although there are no signs to make drivers aware of the altered limit, the limit is signed on most roads where it applies. Los Alamos County alters the urban default and absolute speed limits to twenty five miles per hour and 50 mph respectively, but posts signs at county lines. The speed limit on NM 502 between San Ildefonso Pueblo and Pojoaque Valley High School had a 65-mph speed limit. In November 2005, the stretch between NM-4 and Pojoaque became a safety corridor. In 2007, the speed limit on the San Ildefonso-Pojoaque stretch was lowered to 55 mph. On Highway 68, the speed limit is 60 mph on much of the four-lane stretch between Española and Velarde. Minimum 65 left lane signs are posted on I-40 west of Albuquerque, a night speed limit of 30 mph is posted on State Highway 7 west of White's City going into Carlsbad Caverns. Truck speed limit signs are rarely posted. One road has a posted limit of 45 mph/trucks:35 in Escondida, just north of Socorro, and US 82 east of Alamogordo has a posted limit of 55 mph/trucks:50 for approximately a two-mile stretch. As of December 24, 2009, US 54 still has a 55 mph speed limit north of Tularosa. Yet NM-9 and CR-A003 have a 65 mph speed limit east of Columbus to NM 136 near Santa Teresa. CR-A003 (Columbus-Santa Teresa Highway) is the only county road in New Mexico to exceed the statutory maximum 55 mph speed limit for county roads. Interstate 10 was 70 mph between the Texas-New Mexico state line and two miles south of I-25 in Las Cruces until October 2012, when it was