Final answer:
Escape ramps are designed to stop runaway vehicles safely by using an uphill incline filled with gravel or sand to arrest momentum, especially for large trucks with brake issues on steep roads.
Step-by-step explanation:
Escape ramps are safety features commonly found on steep downhill roadways, designed specifically to stop runaway vehicles that can no longer brake sufficiently. When brakes fail or overheat, especially on large trucks, the driver can steer onto an escape ramp. These ramps use an uphill incline filled with gravel or sand to arrest momentum, safely slowing and eventually stopping the vehicle without causing more damage or potentially leading to a more severe accident. These ramps are critical for preventing accidents that can result from the uncontrolled descent of heavy vehicles on steep grades.