Normally brakes should not make any noise when driving down the road and if the brakes are making noise while driving then likely the wear indicator on the brake pads are touching the rotors and means that the brake pads need replaced.
Your brake pads could also be grooved or your brake rotors are warped and are rubbing against the brake pads when the rotor spins around while going down the road.
If your brakes are making a grinding noise when you press on the brake pedal that is most commonly caused by contact with the rotor disc with part of the caliper.
If your brakes are making any kind of noise while driving down the road you should have them checked out because the brakes should be noise free when you're going down the road and they may squeal when stopping which isn't always bad but sometimes can indicate a problem.