C.R.S. § 42-4-1009
42-4-1009. Coasting prohibited
42-4-1009. Coasting prohibited. (1) The driver of any motor vehicle when traveling upon a downgrade shall not coast with the gears or transmission of such vehicle in neutral.
(2) The driver of a truck or bus when traveling upon a downgrade shall not coast with the clutch disengaged.
(3) Any person who violates any provision of this section commits a class A traffic infraction.