the vast majority of road degredation isn't due to weather, its due to weight wear. As heavy vehicles travel down the road, they create a "ripple" on the road surface in front of the axle. You can create a similar effect if you run your hand across a loose sheet on top of your bed (you will see the wrinkle in the sheet in front if your hand). This bending is the method of road wear that causes like 99% of the maintenance need.

If that were the case, then roads would be almost equally bad everywhere regardless of the weather.

As a Michigander, the dictionary does not contain words to express how strongly I disagree with that implication.

Weather alone does very little. Weather + road ware makes things dramatically worse much faster. You can see this effect with private driveways in the north vs public roads in the south assuming similar construction.

As someone who migrated to upstate new york from Florida, I disagree. People here are constantly repaving, repairing, and resurfacing their driveways and sidewalks. While you need an initialization crack, that can come from a host of issues other than heavy vehicles including thermal cycling and initial defects. I will note that the asphalt and concrete construction may be different in the south vs. the north, but there is much much more driveway repair up here than there was in Florida.

As a pedantic side note, this is why your batteries die, the copper leads begins to fatigue and fracture due to stresses from thermal cycling.

No, the batteries "die" because cold weather requires more energy to start the car and batteries are far less effective when cold. (Physically they die either from grid corrosion increasing resistance so they can't provide enough current to start or the plates shedding active material to the point where they can't hold enough charge). There is normally not any copper in a standard car starter battery.

Copper? I thought batteries were primarily lead.

Northern roads are often (but not always) designed with more substantial shoulders to mitigate frost heaving on the edges of the road bed and plow damage.

While I may disagree with GP about the exact method of wear, regional differences are mostly due to construction not weather or wear. Roads ~50km west of us look almost new, while ours usually develop potholes or at minimum cracks, within a year. It's a different country, so different standards.

Frost heaving is also a significant contributor to road wear in winter areas.