[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).