Driving on the Motorway & the de Facto/de Jure Gap

Curtis Melvin, a colleague and friend from work, alerted me to this very interesting short movie made by a group of students. The movie was made as part of the Campus MovieFest—“the world’s largest student film festival,” as they say on their website. In addition to the fact that the movie was made in less than a week and using iMovie, it illustrates a crucial insight of the economics of institutions.

The initial idea of the team of students led by Jordan Streiff, Amanda  Hunter, and Andy Medlin from Georgia State University was to show that the 55 mph speed limit rule on many US motorways is poorly respected. In order to do so, they decided to drive four cars on the motorway and to line them up side by side while respecting the exact speed limit of 55 mph. The result came quickly: they slowed traffic down and got all the drivers stuck behind them mad.

This is a great illustration of the gap that may exist between de jure rules and de facto ones. That is, the difference that may exist between what the law says and what people do. The students showed that hardly anyone respects the 55 mph speed limit on US motorways. Rather, the speed most drivers spontaneously choose to drive at seems to be more around 70 to 75 mph. My point here is not to debate what the optimal speed limit should be (this is another issue), but to show that in the absence of strict enforcement (and this is the problem), the de facto speed limit rule is very often different from the de jure one: there is a gap. Legislating rules that cannot be enforced seems to be part of what governments often do—even in the developed world.

Comments

[Malachi]

It probably goes without saying that maintaining an artificially low speed limit gives the police an opportunity to pull anybody over anytime they want.

Heck, they could probably even pull you over for obeying the speed limit by claiming it was suspicious. Only criminals with something the hide would obey the speed limit in fear of being pulled over!

Probably a good source of revenue too.

[Daniel J. D'Amico]

I think Malachi makes a good point, that artificially low speed limits give the state the opportunity to pull over anyone anytime. In fact randomized traffic checks have served a more effective means of tracking down fugitives than has the dismal effort of state sponsored investigations.

[El-Visitador]

"that maintaining an artificially low speed limit gives the police an opportunity to pull anybody over anytime they want"

Correct. But isn't it speculative to suppose that legislatures are devious enough to have designed it that way?

I am under the impression it is the environmentalist lobby that has us chained.

Considering the advances in auto engineering since the interstate roads were designed in the 1950's, we should be driving at about 90 MPH with less risk than our parents did at 55 MPH.

To many people, 80 MPH may seem fast, but that is because they are not used to it, even though it is well under their car's performance envelope.