Why can the speed limit be lowered on certain streets?
In most cases, lowering the speed limit on certain streets will not slow traffic. The majority of motorists travel at a speed in which they feel is reasonable speed given the surroundings of the street, regardless of what the posted speed limit signs read. The basic speed law states that no person shall drive at a speed greater than is reasonable or prudent. Therefore, the State of California has established the 85th percentile speed, or critical speed, as the sensible speed. This is the speed at which the large majority (or 85%) of the motorists are traveling at or below. For this reason, the state law requires speed limits to be posted at the first 5mph increment below the 85th percentile speed in order for law enforcement to use RADAR.
