[dsfyu404ed]

You can't just slap a 25 sign on a stretch of road where 90% of people feel like 30 is reasonable 90% of the time and expect people to go 25. Without Orwellian enforcement that does not work, not enough people will comply with the new limit. You need to make people actually feel like 25 is the right speed to go. Allowing on street parking on one side (less space for lanes) planting trees on the sidewalk (visually narrower), tuning traffic lights to create congestion , narrower lane markings and all sorts of other things can do that. You can try Orwellian enforcement but that will not fly in any American city (though it may take longer to crash and burn in some cities than others).

[ryantgtg]

In California, you literally can't "slap a 25 sign on a stretch of road where 90% of people feel like 30 is reasonable 90% of the time." That would be a violation of the vehicle code, which states that speeds are determined by the 85th percentile of operating speeds.

[dsfyu404ed]

As far as "laws CA has that most places don't have" that seems like one of the few reasonable ones. (and I say that as someone who has spent way to much time reading up on traffic and vehicle speed related things). In addition to delivering reasonable speed limits in most places it prevents towns from lowering speed limits in key areas to enable law enforcement rent seeking and probably saves countless hours of arguing over speed limits in local government.

[ryantgtg]

Another perspective is that "speeding leads to increased speed limit."

Generally, many streets are not designed in a context-sensitive way, but instead designed to fit the standards of a limited functional roadway classification system (arterial, collector, local). The passive safety approach of the '60s, as championed by the NHTSA, assumed that crashes are inevitable, and so the safety focus was put on preventing injury after a crash. Thus arterials, for example, have a similar design in which many roadside objects (trees, signs, lights, bollards, etc) were removed, with a "soft landing" on the side. And now we have big wide straight streets that, in their design, encourage us to drive faster.

There are extensive efforts to revise this CA law because of the unintended consequence that it makes roads more dangerous for non-vehicular travelers.

[amanaplanacanal]

Unfortunate when that "soft landing" is a pedestrian or somebody on a bicycle :( At least the driver wasn't injured, I guess.