You need to charge not only by the size of area to be cleared but also have a rate ie: 1-3" 3-6" 6-10" etc. Also if you want you can add a small fee to salt the driveway and any other areas to be shoveled. A 4 car driveway is rather large 16' x 40' on average & $20.00 seems cheap.
HHIS I suohld have thought of that!
this story is weird. okay. so yesterday, my mom was coinmg home and she was driving the car to the driveway. the first two wheels got over the ice but the next two wheels wouldn't go over, so me, my sisters,and my dad came out and pushed the car back. it took a half an hour to do it!