Running from Police

I learn the craziest things from cab drivers.
Yesturday I was out for a meeting with a non-governmental group near the University of Legon.
In the cab ride back, my cab driver starts bussing a youEE (translation: completing a harried U turn). Why? To avoid an "informal" police checkpoint.
The driver complained that he works all day to earn enough fares, and then some jerk policeman stops drivers for no reason and demands payment of "fines" for chumped-up reasons.
So I guess when the police have some integrity deficiencies (diplomatic speak meaning corruption) then you just have to avoid them.
As we began to pass another policeman, I asked the driver why he did not take similar action to avoid this second officer. The driver replied "he does not have a car."
Since the second police officer was on foot patrol, he could not cause too much problems to the car. "If they [police] have a car, they can chase you."
Oh and by the way, among the countries in this sub-region (west Africa), Ghana has the most professionalized police force.