Changing This Law Could Reduce Traffic Deaths

They aren't part of the built environment, but laws often dictate how safe places are to use. According to a piece by Andrew Said, California's speed limit laws are outdated, and unsafe streets are the result. 

For example, "In Los Angeles, police are unable to ticket speeding drivers for violating the posted speed limit on 75 percent of the city’s streets. Why not? It is because the speed surveys required by law for these streets have expired." 

Those speed surveys set limits based on the "prevailing speed." That is, how fast cars are travelling in the 85th percentile. "Once this speed of majority drivers is determined, the law only allows an additional 5 mph reduction to account for unforeseen safety conditions." And that's a truly auto-centric legal method. 

"In countries with the highest rates of bicycle ridership, the severity of injuries caused by crashes at a given speed is taken into account when establishing speed limits. This approach is known as Injury Minimization, or Safe Systems. The idea is to minimize the probability of death and serious injury." 

Said notes that in California, Injury Minimization already exists in mandated 25-mph school zones, which must conform to that limit regardless of prevailing speed. "What about designating a pedestrian zone? Or an active transportation zone? The same rationale of protecting vulnerable road users could apply."