If you must shift the car into reverse as a result of brake failure, what is the fastest speed that your vehicle can be traveling to execute this maneuver?

driver should be immediate shifting to lower gear for reduce the speed of the car

Explanation:

solution

if in any case of a brake failure,

then the driver should shift the car into reverse to help reduce the speed of car

so as that by  maneuver that can only be execute when car is travel not getting speed faster than 25 (mph) miles per hour.

so at speed over 25 miles per hour

then driver should be immediate shifting to lower gear for reduce the speed of the car

answer; the government can clearly justify the restriction;

answer; expert witness;