> The wear and tear on tarmac is directly related to the weight of the vehicles that use it.
From empirical studies, damage to the road is proportional to the fourth power of axle weight. A bike with rider may weigh 200 pounds, where a passenger car weighs around 4000 pounds. That 20x difference in weight results in a 80,000x difference in damage to the road.
(That’s not even getting into semi trucks, which are around 40 tons fully loaded. Split along 5 axles rather than 2, that’s 9x the axle load of a passenger car, leading to 6,500x the damage to the road relative to a passenger car, or 520 million times that of a bike.)
[0] https://en.wikipedia.org/wiki/Fourth_power_law