This is a great analysis but it does focus exclusively on ‘roughness’, which is obviously important but isn’t the be-all-end-all of road quality.

One area I notice in particular that roads in the northeast US subjectively feel worse than Europe is in quality of road markings. Constant plow scraping and harsh salting seems to destroy markings.

I think it also shows up in the overall fit and finish of road infrastructure - edging and barriers, signage, lighting, maintenance of medians, how curbs and furniture contribute to junction legibility… and of course bridges.

One major reason is that European countries typically have national road agencies and consistent standards across the country (because, generally, smaller and less federal). US’s patchwork of federal, state and local road maintenance leads to vastly different budgets and department priorities across the network.

You have a good point. I live in Michigan and recently traveled down to Austin, Texas. The roads didn't seem all that much better but all of the road markings really stuck out to me. Reflectors in all the lines separating lanes, soft bollards surrounding cross walks and parking areas, extra curbs built in for bike lanes. It makes things look a lot nicer but my first thought was, "could you imagine trying to plow around those bollards, or those reflectors would get ripped up on the first pass."

Just FYI, at least germanies rods are also a patchwork. E.g. there are the Autobahns, which are financed by the federal state. Than there are Bundesstraßen (Yellow markings, typically something like B56) which are also financed by the federal state.

Then there are Landstraßen, which are financed by the Bundesland (state, LXXX). Followed by Kreisstraßen, financed by the Gemeinde (county?`).

Finally there are Gemeindestraßen, financed by the city or town.

There are lots of norms and regulations on how to build these roads, so there is not that much variance except layout. E.g. a bike friendly city like Münster has a dfiferent layout than say Cologne.

The reflectivity of the road markings in North Carolina—where plows are rarely used—is terrible, to the point that they are almost invisible on a rainy night, even on freshly painted roads. It's the worst of anywhere I've lived or driven in the U.S.

Relatedly, recently my wife mentioned seeing a vehicle with large boxes on each side and wondering what they were. From her description, I tracked down that they are a fleet maintained by a small company that measures road marking reflectivity:

https://www.beckenterprises.com/services/

So who knows, maybe NC is finally doing something about the road markings here.

I generally agree but need to point out Germany is organised like the US regarding road construction. Only Autobahnen and Bundesstraßen are under federal authority, with states and municipalities divvying up the rest.

Well then there's the overall experience using the roads, regardless of roughness. For example, Texas' under interstate turnarounds are super weird and make running a local errand feel like a cross country trip as an example. Areas without zoning laws between commercial / residential feel more stressful to me as a driver personally too.

While I agree on your additional criteria, I feel the roughness metric itself (at least as explained here) is not as informative as it could be: a generally smooth road surface with sudden discontinuities in level (e.g.potholes) seems qualitatively worse (and damaging) than would be a smoothly-varying one with the same roughness. Perhaps an alternative metric might be based on the maximum speed at which a typical car or truck could travel without experiencing vertical accelerations above a certain threshold? ('typical', here would be with regard to things like its mass, suspension travel and stiffness, and wheelbase.)

> focus exclusively on ‘roughness’

also, as a road cyclist I've found that there are different types of paved roads, some are very smooth (asphalt I presume), and others are less so (concrete?). Both are paved, but one is much more pleasant to ride on than the other. I don't know if there is a relationship between roughness and durability or quality, or those are just different techniques.

>Constant plow scraping and harsh salting

We have no problems with that here in Scandinavia. Also, salt is not used in very cold areas as it doesn't work.

>European countries typically have national road agencies and consistent standards across the country

(I'm guessing you meant EU, since the largest country in Europe is Russia.) We have EU wide standards in the EU.

For what it’s worth I hate the roads and parking in Europe. Roads are narrow, intersections are chaotic and parking is a joke. I drove around Europe for around 3 months (France, Spain, Italy, Germany, Belgium etc.) and longed to drive back in the US again.