§47-12-302.

§47-12-302.
   
   Every motor vehicle or combination of vehicles, at all times and under
   all conditions of loading, upon application of the service (foot)
   brake, shall be capable of (a) developing a braking force that is not
   less than the percentage of its gross weight tabulated herein for its
   classification, (b) decelerating in a stop from not more than twenty
   (20) miles per hour at not less than the feet per second per second
   tabulated herein for its classification, and (c) stopping from a speed
   of twenty (20) miles per hour in not more than the distance tabulated
   herein for its classification, such distance to be measured from the
   point at which movement of the service brake pedal or control begins.
   
   Braking
   
   force as a
   
   percent- Brake age of system gross applica- vehicle Decelera- tion and
   
   Classification of or com- tion in braking
   
   vehicles and bination feet per distance
   
   combinations weight second in feet
   
   __________________ _______________ _____________ _____________
   
   Passenger vehicle,
   
   not including
   
   buses................ 52.8% 17 25
   
   Single-unit vehicles
   
   with a manufacturer's
   
   gross vehicle weight
   
   rating of less than
   
   10,000 pounds........ 43.5% 14 30
   
   Single-unit, 2-axle
   
   vehicles with a
   
   manufacturer's gross
   
   vehicle weight rating
   
   of 10,000 or more
   
   pounds, and buses not
   
   having a manufacturer's
   
   gross vehicle weight
   
   rating............... 43.5% 14 40
   
   All other vehicles and
   
   combinations with a
   
   manufacturer's gross
   
   vehicle weight rating
   
   of 10,000 or more
   
   pounds............... 43.5% 14 50
   
   Tests for deceleration and stopping distance shall be made on a
   substantially level (not to exceed plus or minus one percent (1%)
   grade), dry, smooth, hard surface that is free from loose material.