It would be like making it illegal, for people to flash their lights at oncoming traffic, to warn of an upcoming speed trap.My answer might surprise some folks on here...... ban neither.
I have one of these applications on my cell phone as well. Its called "Trapster" I believe. (I put it on there so I can see when people are reporting me running stationary radar as a "Speed Trap" )
The information is obtained from OTHER USERS reporting the activity. I find absolutely no reason why the government should ban communication between individuals on the internet.
If anything, these programs, more specifically the ones that report "speed traps", are doing our job for us. The job of law enforcement enforcing traffic speed laws is to keep people driving at a reasonable speed so the harm done during a crash isn't unnecessarily higher than it should be. If people see the "speed trap" warning on their application, they will be wary about going fast. That is going to make them drive at a reasonable speed, thus doing our job for us. This same can apply to the red light camera systems. If people see it, they are going to make sure they do not run that red light. Which is going to increase traffic safety at that intersection, and other intersections where the same thing is occurring.
As far as the DWI checkpoint aspect is concerned. The person may decide to call a cab instead. The person may decide to try to take an alternate route, however, I highly doubt the person who would do so carefully planned this out a head of time based upon the information they received, they may have received a warning as they were approaching the area, which means they are screwing around with their phone and are probably a prime candidate to get pulled over for swerving on the roadway anyways not to mention when they get within eyesight of the checkpoint and then decide to turn around, many jurisdictions are authorized to stop a vehicle that turns around at a checkpoint. And, lastly on the DWI checkpoint issue....... DWI checkpoints do not occur so often that this would be an often enough used feature of the application, and DEFINATELY not worth banning the application.
Because in the end... the people are allowed to have free exchange of ideas...