The costs of a cycling path that support the same flow of people is negligible compared to that of a corresponding highway.
The reason sidewalks last so long is they're made of cement rather than asphalt. If you made roads out of cement they would last just as long if not longer.
And the reason they make sidewalls out of cement is they have to. If they made then out of asphalt they would decay very quickly.
Or, just calculate it?
Car contact patch is 4 x 160cm2. https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=... Car avg. weight is 1800kg. https://www.bankrate.com/insurance/car/average-car-weight/
Pressure = 28kPa
Human is 100cm2. https://en.wikipedia.org/wiki/Pedobarography Average human weight is 75 kg.
Pressure = 8.5kPa.
So it's simply not true what you say.
Compare that to a road where the truck literally forms grooves into the asphalt. It ripples like the viscous material it is in those conditions under multiple tons of weight. An intersection by me looks like its plaid with the grooves from perpendicular trucking traffic. And cement roads do last a long time but they aren't indestructible. I live on one. Trucks damage them and crack them up over time and the city has to fill in potholes. The more construction going on the more damage. Any big apartment build just destroys the concrete apron and sidewalk on the lot with the equipment because its that heavy. Orders of magnitude heavier than any human on a bike can be.
That's not true The ground pressure of a bicycle is higher than the ground pressure of a car.
Some bike tire pressures exceed 100 psi. Only the largest trucks have ground pressures that high. A typical passenger vehicle has a pressure of around 36 psi.
The ground pressure of someone in heels is even higher than that. There's a reason sidewalks are made of cement while roads can be made of cheaper asphalt.
