In general, we don't tax and license people who use the roads. There is no licensing pedestrians, for example. And there was no licensing ox-carts in the 19th c

In general, we don't tax and license people who use the roads. There is no licensing pedestrians, for example. And there was no licensing ox-carts in the 19th century. Similarly, when the safety bicycle was invented and popularized in the 1890s, there was no licensing for it. The change came with the automobile, which has huge mass and travels at high speed. The danger of the automobile to all other road users was so profound and unique that the need to license motor vehicles soon became quite clear. And even with driver licensing, cars kill thousands of people every year. Bicycles simply do not pose much of a threat to other road users, that would require cyclist licensing. Similarly, a 250-lb cyclist does not cause much wear and tear on the roads compared to a 2,500-lb motorist. Roads are more expensive because they have to be built for cars.