Sure, you can walk on asphalt, but they don't offer the same traction on asphalt, and the shoes wear out faster. Studded soles can be compared well to car studded tires: the grip is good on ice and snow, but not on asphalt. And if you drive a lot on asphalt, the studs wear out quickly and also come off. They are not intended for asphalt surfaces. How much or how quickly the studs wear, therefore, depends entirely on the use.