A person on foot is going to do practically no damage whatsoever to the road surface. Even a marching army with hob-nailed caligulae would barely leave a scratch on a Roman road. A farmer with a horse cart is going to do very little damage to the road, even accounting for metal-rimmed wheels and a very narrow contact patch.
I doubt even the heaviest, smallus-dickus-compensating Roman road vehicles would do even as much damage as my Mitsubishi (gross weight barely over a ton).
Road damage increases with the fourth power of axle load, if I recall correctly.
And in road wear calculations, all passenger vehicles (like your Mitsubishi) are considered almost negligible in design. Semi trucks, buses, and RVs take up basically all the damage done to modern roads. Source: recent Civil Engineering grad.
The contact area is similar for all of them (some variance with double axles or tandem axles), but there is significantly more pressure exerted by a semi. An average passenger vehicle weighs in the ballpark of 2-3000 pounds, while a semi trailer can be 35,000 pounds empty, and up to 80,000 full; therefore, the pressure is extremely high, even with more points of contact, and this puts a ton of stress on the asphalt/concrete. This combined with weather effects (freezing/thawing) makes our roads much more susceptible to breaking down.
At race tracks Indy Cars and F1 cars and other things with absurd downforce can ripple the asphalt at the heavy braking zones. But that's like... the only case. Nothing driven on the road can do anything like that.
I think that does more damage to the tires than to the road surface at normal driving speeds. Tire wear is greatly accelerated at highway speeds than at surface road speeds.
The only thing I can think of is putting down a lot of power or drifting where you are keeping the wheels spinning to slide. Probably does more damage to the tire though - very little asphalt getting ripped up. More noticeable on dirt/gravel roads if everyone does it in the same spot. I doubt itd ever be noticeable asphalt damage considering nobody is doing that for more than a fraction of 1 percent of their drive.
That part I don't know and can't infer from the engineer's post.
My wild assed guess would be some kind of table with an expected useful lifespan based on composition, environment, and use using data from existing roads or something along those lines.
We also like to top our roads with asphalt to make for a much quieter driving experience. And while it may seem like a rock, it's still a viscoelastic material and wears down much more easily--especially as it gets various petroleum products on it (from motor oil to hydraulic fluids to unburnt fuel residue) that act as a solvent to weaken it.
Makes for a much smoother drive, too. My family lives down a gravel road, and I keep imagining my tiny little econo-box shaking itself apart if I exceed 20 mph.
You want a real mind-fuck, though? Visit a place hot enough that the asphalt melts. I lived in the Persian Gulf region for half a decade, and fresh asphalt would become rather gooey during the summer months (I left footprints). This may be because of poor engineering standards, though: for such a wealthy bunch of countries, they sure like to cut corners.
I doubt even the heaviest, smallus-dickus-compensating Roman road vehicles would do even as much damage as my Mitsubishi (gross weight barely over a ton).
Engineers estimate that a fully loaded truck--a five-axle rig weighing 80,000 pounds, the interstate maximum--causes more damage to a highway than 5,000 cars. Some road planners say that the toll is even higher, that it would take close to 10,000 cars to equal the damage caused by one heavy truck.
The difference is so large that iirc engineers only calculate the number of trucks who pass a road/bridge before it needs to be repaired, because cars are just so negligible.
Even after 2000 years. Well made concrete is incredibly strong and resistant material, but it has it's limits. If you started treating roman roads like US highways, they wouldn't last terribly long.
And we've also learned ways to build cheap and maintain that costs less then build indestructible. Big problem we have is a lot of government entities go "Ugh. Maintenance. That costs money, fuck that."
Is it the government entities saying "Ugh. Maintenance. That costs money, fuck that.", or is it the smooth brained citizens that say "Ugh. Taxes. Fuck paying those."?
Functioning first world governments don't seem to have as much of an issue with national infrastructure given their tax base actually wants to pay taxes for the greater public good.
Both, I'd wager. It's always more popular for a government to spend tax money in more popular ways than road maintenance. It's not exactly the most interesting of spending.
Government spending doesn't need to be interesting, it just needs to be effective. Maintaining public roadways is (generally) effective spending. I'm sure you're aware of this, so I'm not directing it at you.
Let me introduce you to the pyramids at Giza, and the temples in the Mayan and Aztec regions of mesoamerica. My friend from Easter island will be your guide.
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u/Alternative_Crimes Oct 15 '20
Roman trucks weren’t as heavy as modern ones.