It has been found that bike riders make better drivers. Why? Because they recognize their vulnerability on a bike and are more cautious. It is a learning experience. Yes, there are idiots on bikes, but they don't kill like idiots in cars. It is a matter of speed and mass, which is why some cities are reducing speed limits in residential areas to 20 or even 15 mph.

Governments have generally dropped registration of bikes because the cost of doing so is more than the income. Then there is the fact that most bikers own cars and pay the same gas and registration taxes that other drivers do. To which you can add the fact that user fees pay for less than half of the cost of streets, roads and highways. Where do the funds come from? Property taxes, local bonds and the general fund. Everybody pays those, directly or indirectly. Yes, renters pay property taxes, albeit indirectly.