21 cars, 90 passengers, 5 bays. 80 seconds on the clock.
90 waiting
You have 80 seconds, starting at your first tap. A bump costs 3 seconds.
Call the cars to the stop in this order: 15, 17, 13, 4, 9, 18, 11, 1, 5, 7, 3, 10, 16, 8, 14, 19, 2, 20, 21, 12, 6.