Final answer:
On a hill, maintaining a safe following distance of 1.5 to 2 car lengths behind the vehicle in front of you is recommended. Road conditions and your vehicle's braking capabilities should be considered to adjust this distance accordingly.
Step-by-step explanation:
When stopped behind another vehicle on a hill, it's essential to maintain a safe following distance to ensure you have enough space to react or stop if the vehicle ahead moves unexpectedly. General driving safety guidelines recommend staying at least one car length behind the vehicle in front of you for every 10 mph you are traveling. However, because of gravitational forces on a hill that can cause a vehicle to roll back, it is advisable to stay back slightly more than this, such as 1.5 to 2 car lengths, to give yourself additional safety margin.
It's also important to consider other factors such as road conditions and your vehicle's braking capabilities. If the road is wet or icy, or if your brakes are not in top condition, then increasing your following distance even more may be wise.