[mikeryan]

how much blame should be allocated to the traffic engineer that clubbed a 65MPH California freeway directly into a 45MPH local business street with no traffic-calming measures or other mechanism to signal to a sleepy human brain that the rules of the road had changed besides a lone speed limit sign and a "Good luck sport!" attitude.

None. The answer to how much culpability the traffic engineer should have is "none". Freeways end that's what they do and there's no expectation that they won't have a light, or a traffic jam or a deer or some other obstacle in front of you that you'll have to stop for. Lights crossing two-lane highways happen all the time outside of urban areas.

Drivers are, appropriately supposed to be alert enough to see a red light up ahead. Of the twenty-two accidents you cited how many do you think would have been prevented with more signs?

For that matter it's not the autopilot's fault either its the fault of the idiot driving (or not driving as it were).

[shadowgovt]

I agree with your thinking; invoking the responsibility of the highway engineer was intended as a counter-example.

And when you dig into the five-year numbers, you find that while 22 is quite a bit, there have been more on the straightaway highways north-southbound east of the intersection and on the cloverleafs (If I were to hazard a wild-ass guess, based on California driving experience: driver going highway speed failing to realize traffic came to a standstill on the highway due to back-pressure of people exiting the cloverleaf at rush-hour).