Originally Posted by genec
What is the speed delta between you and the motor traffic as you ascend that hill from Sorrento Valley Blvd (VSP BTW is 50MPH as you go north, 60MPH as you go south).
A distracted motorist will close on you much faster (and thus have less time to react) at 50 or 60MPH than at 40 or 45MPH... it may only be a second or two difference, but that may be all YOU need.
Now the flip side is with a parallel freeway, why does any motorist need to drive at freeway speeds on a surface street? Further, the speed was set long before all the apartments, businesses, and stoplights in that area were put in... from a practical sense alone, only the most powerful cars can even hit 50MPH between those lights... yet the road is marked at ludicrous speed. Rather than ask "why" as in "why not that speed..." ask "why" as in "why that speed at all."
I have yet to hear a decent justification for high speed surface streets that are paralleled by freeways. Freeways offer the ability to access the same locations at high speeds and in a controlled manner... parallel surface streets should be speed limited to serve those that cannot access the freeways. (pedestrians, cyclists, heavy loads, etc.)
The justification for the higher speeds is increased traffic throughput to all the new housing up there.
As for the speed deltas, we're probably going 15-20 up that hill in a group, maybe closer to 12-15 when I'm solo.
But the group is more visible than slow contruction vehicle would be there, and we're usually oozing out of the bike lane into half of the rightmost traffic lane (big deal, there are two more same-dir lanes).
When I'm solo I monitor for traffic to the rear as always and move aside into the bike lane as they approach.
Closing speed and not noticing is not an issue.
Is there any evidence for correlation between speed limits and crash incidence and/or severity? That is, is there any basis for the claim that lower posted speed limits make things safer?