“Speeding, Coordination, and the 55 MPH Limit”, 1985-12 (; similar):
This paper tests these differing views of the law by examining the current effects of the 55 mph National Maximum Speed Limit (NMSL)—should it be viewed as a coordinating mechanism or a limiting mechanism?
I measure the effects of limit-defying behavior (speeding) and absence of coordination (speed variance) on the fatality rate. Based on analysis of 1981–198242ya state cross-section data, I find that:
there is no statistically discernible relationship between the fatality rate and average speed, though there is a strong relationship to speed variance. When most cars are traveling at about the same speed, whether it is a high speed or a low one, the fatality rate will be low—presumably because the probability of collision will be low.
Variance kills, not speed.