When descending a long, steep mountain gradient in Austria (e.g. Brenner Autobahn A13 descent or Tauern Autobahn A10) with a 40-tonne truck, what is the safest braking strategy to prevent brake fade?

1. Select an appropriate low gear that keeps engine RPM in the upper continuous braking band (1,800–2,100 RPM), utilize the retarder/engine brake as primary deceleration, monitor engine coolant temperature, and use the service foundation brakes only intermittently for short, firm snubs if speed rises
2. Shift into neutral and ride the service brake pedal continuously with light pressure throughout the entire descent
3. Rely 100% on the foundation service brakes to keep the retarder cold
4. Pull the trailer handbrake continuously to stretch the combination