Rational Deterrence

Two days ago, I was traveling on the highway. The vehicle I was on was traveling slightly above the speed limit. During one part of the course, the traffic at my direction slowed down. To my left, I saw a police car parked at the side with its flashing lights on.

I wasn't surprised, because drivers were known to slow down in areas where there are hidden speed cameras. They would slow down near the location, and after they passed, they will continue their "beyond speed limit" speed. (Generalization here).

But what is surprising here was that the drivers, after passing the police car, did not speed up. In fact, the traffic remains within legal speed limits for quite some time before it resumed back to the "norms".

Some thoughts came to my mind.

1) Drivers were very rational and very "preemptive". A police car does not necessary mean that only that specific portion of the highway was being marked. It may just be a start of a series of law enforcements waiting for you right till the end of the highway.

(2)Traffic law enforcements may know the above point(pt 1), and hence may just employ one vehicle to achieve the effect, thereby saving on manpower.

(3) Some experienced drivers may know the above point (pt2), hence may be unfazed and may step up the gas after passing that single traffic police car.

(4) However, some drivers may not know point 2, hence they will take extra precaution and slowed down. And because of these drivers and the collective effects, it will overall, still slow down the highway speed.

(5) The law enforcement teams know all of the above, hence, their equilibrium strategy will still be - the deployment of one police car.