Straight to the point: Speed Demon is 4 traffic lanes starting at 360 px/s, playable in your browser right now. It is tuned for quick runs, honest difficulty, and controls that make sense the first time you touch them.
Traffic scrolls down 4 lanes and never stops; you weave between cars, and the closer the pass, the bigger the near-miss bonus. Coins appear in risky places - exactly where you would rather not be - and the speed climbs the whole time.
It suits anyone with a queue to wait in or a kettle to watch: students between classes, commuters, parents stealing ten quiet minutes. There is no meta-progression to lose and nothing to catch up on - a week away costs you nothing but a little sharpness.