The idea is interesting, but not promising. The main reason is energy costs. I will explain. An ordinary household hair dryer consumes approximately 0.375 watts for 15 minutes of operation. High-power hair dryer (construction) - about twice as much. For efficient operation, there must be at least 20 nozzles under the bottom of the machine. We get about 17 watts for 15 minutes of work. In order to clean a street 2 km long, it will take about 1.5 hours and we get about 102 watts. For an hour and a half of work. Now imagine that such a system works for several hours every day. And there are dozens of such cars. Plus, there are technical problems (a high temperature under the bottom will contribute to overheating of the vehicle. Sprinkling salt or other chemicals on the snow is much more profitable, easier and cheaper.