When faced with brake failure on a downgrade, the most critical first step is to look outside your vehicle for any means of slowing it down. This could include seeking out a soft shoulder to steer towards, looking for other vehicles to signal for assistance, or identifying an escape ramp specifically designed for situations like this one.
Taking this action allows you to assess your surroundings and possibly utilize safety features or structures that can help slow the vehicle down before a complete loss of control occurs. Identifying alternatives outside of your vehicle, such as roadside barriers or other natural terrains, can provide immediate options to help manage the situation.
The other options involve more dangerous approaches. Hitting an object to bring your vehicle to a stop can cause significant damage both to your vehicle and whatever you may hit, potentially resulting in injury to yourself or others. Waiting for an escape ramp can also lead to a perilous situation if your speed continues to increase on the downgrade, thus making it crucial to look for other quick, viable options immediately.