Think about it. Long distance travel has been, for as long as humans have recorded history, a risky affair. In recent times, the stagecoach lines were magnets for criminal attack, and only a fool would go unarmed. Today, it's not much safer, though there are somewhat fewer four-legged predators around.
But somehow, once the common man has an affordable means of protection, the governing "rulers" step in to deny him that ability. They place checkpoints and authorize the broad search of citizens who have done no wrong, whose only infraction is the seeking to execute an absolute good in the face of attack. It's about control ... and not of the predators.
If anything, it's at a place with a greater concentration of people that justifies greater ability to quickly overcome and withstand attack. I have never understood the predilection some politicians have to deem public travel as a protected zone of sorts, that somehow magically demands disarming of innocent people.