State Route 99 (SR 99) is a north–south state highway in the U.S. state of California, stretching almost the entire length of the Central Valley. From its southern end at Interstate 5 (I-5) near Wheeler Ridge to its northern end at SR 36 near Red Bluff, SR 99 goes through the densely populated eastern parts of the valley. Cities served include Bakersfield, Delano, Tulare, Visalia, Fresno, Madera, Merced, Turlock, Modesto, Manteca, Stockton, Sacramento, Yuba City, and Chico. The highway is a remnant of the former Mexico to Canada U.S. Route 99 (US 99), which was decommissioned in 1972 after being functionally replaced by I-5 for long-distance traffic south of Sacramento. The entire segment from Wheeler Ridge to Sacramento has been upgraded as of January 2016 to a freeway at least four lanes wide, and the California Department of Transportation (Caltrans) plans to further upgrade the segment to a minimum width of six lanes and also bring it into compliance with Interstate Highway standards as a parallel route to I-5 for Los Angeles–Sacramento traffic, with plans for it to eventually become either I-7 or I-9. North of Sacramento, the road ranges from a rural two-lane road to a four-lane freeway, with much of it following the route formerly designated as US 99E. From Wikipedia
