8 or 9 years ago, when I was doing my Civil Engineer In Training "paying my dues" tasks, traffic counting was one of my least favorite activities. Nothing more fun than standing on a busy intersection on a 115 degree day in downtown Pheonix with a little clicker box trying to keep up with rush hour traffic.

Believe me, those leave in place air tube counters are a God send for EITs and young PEs in smaller offices with traffic count contracts!

Your observation of seeing an LEO parked near the counter is almost certainly a result of shared circumstances. Counters are generally placed either directly upstream or directly downstream of a predicted significant change in traffic. This includes a major intersection, ramp, lane change, or even a major egress/ingress to a high volume use site (shopping center, sports facillity, school, etc) These are also places where LEOs often stop to monitor traffic and insure drivers are following the law. Both are often seen there for the same reason... higher volumes of traffic. You want to base your traffic counts off of the highest observed peak volume because that will ultimately dictate what type of roadway structural section you design, how many lanes, what turning movements need to be accounted for in signalization design, etc. We use traffic counts a lot in our roadway design process.

As Freud said "Sometimes a cigar is just a cigar."