If you have five spare minutes, Moto Rush 66 will fill them. Everything happens on one screen with 4 traffic lanes starting at 340 px/s, and the whole thing runs straight in the browser - no downloads, no sign-ups, no fuss.
Lane changes are instant but not teleports: the car slides across with a short animation, and during that slide you are committed. Half of the skill is choosing the next lane before you need it, the other half is not panicking when the lane you chose stops being empty.
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.