> People scoff at road construction (or rather, road widening) as a solution to congestion. I don't think anyone is under the impression that kilometers driven would go down as road bandwidth goes up.

It is a solution to congestion because a part of the past congestion was that people were stuck at home and gave up on the trip overall, because it would take so long.

> Maybe some people who would have otherwise used public transport opt to drive instead.

Then presumably comfort increased. Also, add bus lanes.