A few comments have mentioned different levels or road damage caused by different vehicles, with heavier vehicles causing more damage.<p>How much does tire pressure matter in that? If two vehicles have the same weight and number of tires taking the load, evenly distributed among the tires, but one of them runs with higher tire pressure, it will have a proportionately smaller contact area, and so a proportionately higher ground pressure.<p>In general, a tire supporting weight W at pressure P will have a contact area A such that P x A = W.<p>I'd expect total road damage to depend on both area and pressure. Pressure would determine whether you are going to damage the surface, and area would determine how big an area will damaged.<p>For causing cracks that lead to potholes, I'm not sure area matters as much as the pressure, so am curious about lighter vehicles with high pressure tires.<p>My car has a pressure of 32 psi. Back when I was a regular bike commuter [1] my bike had a pressure of 110 psi.<p>Wikipedia has a nice table of the ground pressure of several things [2]. Some excerpts, in psi:<p><pre><code> 4 Diedrich D-50 T2 drilling rig
8 Human male
15 M1 Abrams tank
25 1993 Toyota 4Runner
25 Adult horse
30 Passenger car
40 Mountain bike
90 Road racing bike
470 Stiletto heel
</code></pre>
A bit of Googling suggests delivery trucks are between 85 and 110 psi for most fleets, and around 110 seems to be normal for big rig trucks, too.<p>So...trucks being more damaging than cars is quite believable. More interesting is different kinds of passenger cars. Honda's recommended tire pressure for a Civic and a CR-V, e.g., are largely the same range. Does this mean a CR-V is not much more damaging than a Civic?<p>And where do bikes with high psi fit in? The have the pressure of a delivery truck, but have a much smaller contact area. Is there some minimal area needed before even high pressure damages the road, so bikes are OK? Or is it just that because the areas is smaller it takes longer to cause enough cumulative damage for people in cars to notice?<p>[1] when I lived in flat Cupertino. That died when I move to Seattle and found that fat people on bikes don't get along well with hills.<p>[2] <a href="https://en.wikipedia.org/wiki/Ground_pressure" rel="nofollow">https://en.wikipedia.org/wiki/Ground_pressure</a>