They are comparing a fairly high bicycle+rider weight of 100kg vs a 2000kg car.
A better way to represent the relationship is per mile of trips.
The actual relationship, I think, should be the difference between psi per road contact patch times tires, or at least per tire. On per tire basis times double the tires, a car would wear road 20k times more. Enough for bike to go around the world for each car mile driven.
They are comparing a fairly high bicycle+rider weight of 100kg vs a 2000kg car.
A better way to represent the relationship is per mile of trips.
The actual relationship, I think, should be the difference between psi per road contact patch times tires, or at least per tire. On per tire basis times double the tires, a car would wear road 20k times more. Enough for bike to go around the world for each car mile driven.