What is the operational benefit of Continuous Damping Control (CDC / adaptive electronic shock absorbers) in modern passenger coaches?

1. It completely eliminates the requirement for pneumatic air springs on the front axle
2. It continuously adjusts shock absorber valving in milliseconds based on road surface and sensor inputs, minimizing body pitch, roll, and high-frequency vibration
3. It locks the steering axle rigidly during windy motorway driving
4. It automatically converts braking heat into electrical energy stored in the retarder