well it depends on a few things of how the driver, drives the car.
example: when they go to brake, they wait until the are a few feet away from he car in front of them, then slam on their brakes, some time leaving skid marks. this will greatly decrease the life of your tires and tire treads.
but in a nut shell i believe truck tires a made a little bit stronger then car tires just on the fact of, off-roading, towing trailers, and things like that.
a great way to know when your tire treads are low is to use a penny. not entirely sure but i think now they say to use a quarter and if it is lower then the head, you should change the tires.
hope this helps.