A much more stringent and in consequence structured driving environment. As others have noted, obtaining a license is more difficult. Uncooperative driving behaviour is heavily frowned upon and prohibitions actually enforced: driving in left lane, but also attempts to bully others out of the left lane and overtaking on the right.

As for compression, compare driving in NYC to driving in Berlin.

This isn't to mean that North Americans wouldn't be able to reach this standard if they decided to, but it would take decades.