<P> It is commonly known as a right turn on red (or simply right on red) in countries that drive on the right side of the road, or a left turn on red in countries which drive on the left side of the road . </P> <P> Right turns on red are permitted in many regions of North America . While Western states have allowed it for more than 50 years; eastern states amended their traffic laws to allow it in the 1970s as a fuel - saving measure in response to motor fuel shortages in 1973 . The Energy Policy and Conservation Act of 1975 required in § 362 (c) (5) that in order for a state to receive federal assistance in developing mandated conservation programs, they must permit right turns on red lights . All 50 states, the District of Columbia, Guam, and Puerto Rico have allowed right turns on red since 1980, except where prohibited by a sign or where right turns are controlled by dedicated traffic lights . (On January 1, 1980, Massachusetts became the last US state to allow right turns on red .) The few exceptions include New York City, where right turns on red are prohibited, unless a sign indicates otherwise . </P> <P> In some states, such as New York, North Carolina, and California, a right turn on red is prohibited when a red arrow is displayed . </P> <P> At intersections where U-turns are permitted and controlled by a U-turn arrow from the left-most lane, motorists turning right on red onto the same road must yield to those making U-turns before turning, as the motorists making U-turns have the right of way and a collision could easily occur . At intersections where U-turns are prohibited in the same fashion, a green right turn arrow will sometimes appear with the red light for those turning right onto the road, allowing only traffic turning right to proceed without having to stop or yield to other vehicles or pedestrians . Some states such as California have "No U-Turn" signs posted at these intersections because of the green right turn arrow . </P>

When is it legal to turn left at a red light