Fine, if they stop traffic for mere mortals like myself on special occasions, I'm fine with it too. Just don't go passing special laws just for these folks.
I had a friend of mine who was a local campaign manager for a presidential candidate (not even the President himself, just a major candidate for one of the two big parties). They met with the Secret Service and got to ignore every single traffic sign and signal even though the candidate wasn't even in the car. There wasn't any real emergency, no need to get to a hospital or anything. They just simply ignored local laws of any kind and showed no consideration for stuff like speed limits and such.
I simply disagree that this is something that should happen at all. It shows complete disregard to others who do have important things to do in their lives too, and the imperial king formerly known as The President does not have any special distinction either.
The governor of my state stops at all traffic lights and obeys the speed limit when driving in his limo. I certainly don't see why The President deserves any more special consideration. The local football teams get better treatment, and that is only because the police want to both protect the players from the public and the public from the football players. Besides, the motorcade for the football teams is made up of not just players but also the parents and a couple miles worth of traffic from fans following the procession.