The driver of any motor vehicle when traveling upon a down grade shall not coast with the gears of such vehicle in neutral.
The driver of a commercial motor vehicle when traveling upon a down grade shall not coast with the clutch disengaged.
Coasting upon down grade
Miss. Code Ann. § 63-3-1207, under Reckless or Careless Driving and Miscellaneous Rules.
Miss. Code Ann. § 63-3-1207