Even if you don't drive a car yourself you depend a lot on things delivered by road. Most of the road wear is done by trucks bringing you food, construction materials and whatever else. You can't exactly replenish your local grocery store by rail or cargo bike.
Most of the need for roads though is cars. It is rare to see a multi-lane road where trucks are restricted to only 1 lane and cars allowed the rest - if though trucks wouldn't fill that single lane and in turn the other lanes could be built much cheaper. (in part because the road needed for a car isn't that much cheaper than the road needed for a truck - labor is about the same, and weather is often a large factor)
