On a steep downgrade, if you have reached a safe speed of 40 mph, you should apply the service brakes until your speed reaches what?

On a steep downgrade, if you have reached a safe speed of 40 mph, you should apply the service brakes until your speed reaches what?

• A. 40 mph
• B. 35 mph
• C. 30 mph
• D. 45 mph

Answer: (B)

Downhill driving calls for careful, controlled speed management. Once you’ve reached a safe speed, you don’t stay right at that limit; you give yourself a margin to handle changing conditions and prevent brake overheating. From a safe speed of 40 mph, you should bring your speed down to about five mph below that—so 35 mph—using the service brakes. Then you hold that reduced speed with a combination of engine braking and light brake adjustments as needed. This maintains control, reduces the risk of brake fade, and keeps you prepared for any further changes in grade or traffic. Slowing further to 30 mph isn’t necessary here, while staying at 40 mph or going up to 45 mph would compromise control on a steep downgrade.

Downhill driving calls for careful, controlled speed management. Once you’ve reached a safe speed, you don’t stay right at that limit; you give yourself a margin to handle changing conditions and prevent brake overheating. From a safe speed of 40 mph, you should bring your speed down to about five mph below that—so 35 mph—using the service brakes. Then you hold that reduced speed with a combination of engine braking and light brake adjustments as needed. This maintains control, reduces the risk of brake fade, and keeps you prepared for any further changes in grade or traffic. Slowing further to 30 mph isn’t necessary here, while staying at 40 mph or going up to 45 mph would compromise control on a steep downgrade.