Somewhat harder to do down here. We do have roads that normally flood during storms. So far water floods stays a few days than goes away. Will it always be like that I don’t know.
As you say it is expensive but it’s better than being dead.
You dig two big ditches, put the excavated dirt between them and build a road on top of it.
We do have roads that normally flood during storms.
That's because they're at ground level. People try to drive through the flood water and get killed.
So far water floods stays a few days than goes away.
Meanwhile....you're stranded.
We have our share of lousy roads up here but flooding is seldom a problem. Our issue is ice. Cracks form in the pavement, and they stupidly salt the roads. The water then runs through the cracks and freezes again, which expands. This heaves up and destroys the pavement.
In this case it's a lack of proper drainage in the roadbed composition. It should be lots of fractured rock.