Enforce and Obey Laws

As a citizen of the United States of America, one of the thing I am allowed to do s to voice out my opinions. I don't normally do this but I cannot help but have my say. Every time I pick my son up at school, I see people driving fast than the speed limit especially on the school zone, driving and talking on the phone at the same time and not buckling their kids up. Some of them are parents and some are policemen. Yes, policemen drive more than the speed limit. The thing is that, how would they expect people to obey traffic rules, if they themselves are not obeying/following them. I think that being a policeman doesn't excuse them from obeying such laws. They should not abuse their authority or exercise unrighteous dominion. Sad to say, but it is true. They should not enforce a law that they cannot obey. What do you think?