What makes you believe highways are nearly free? Do all those people doing highway maintenance not get paid? Also, road wear scales with the fourth power of ax

What makes you believe highways are nearly free? Do all those people doing highway maintenance not get paid? Also, road wear scales with the fourth power of axle load. This means a 3-axle 30-tonne truck causes 15.000 times the wear of a 2-axle 2-tonne car. Even if highways are currently "nearly free" to maintain with a car-dominated traffic mix, moving all that rail transport into heavy trucks is going to rapidly make highway maintenance costs explode.