Final answer:
An escape ramp is a safety feature that helps vehicles slow down and stop when their brakes fail. It is made of soft gravel and is located on downgrades. Contrary to one of the options, an escape ramp is specifically designed to assist vehicles traveling too quickly.
Step-by-step explanation:
An escape ramp is a safety feature on roads that is designed to help vehicles, particularly large trucks or semis, slow down and stop when their brakes have failed.
It is typically made of soft gravel or other materials with high friction, which helps reduce the vehicle's speed and bring it to a halt. The ramp may be located a few miles from the top of a downgrade to give the vehicle ample distance to slow down before reaching the ramp.
One of the options given, D. 'Is of no use if you are traveling too quickly,' is NOT true about an escape ramp. In fact, an escape ramp is specifically designed to assist vehicles that are traveling too fast and unable to stop due to brake failure.
The soft gravel, location on a downgrade, and uphill turn of the escape ramp are all intentionally designed to help slow down the out-of-control vehicle.