What must you do to prevent a two-axle bus from rolling down a slope?

To prevent a two-axle bus from rolling down a slope, you need to take multiple safety measures. Engaging the parking brake is crucial as it secures the vehicle in place when parked. Placing a wheel chock under a rear wheel further enhances safety by physically blocking the wheel from moving. According to German traffic regulations, ensuring that such preventative measures are taken is essential for road safety, particularly when parking on inclines. These combined actions help to mitigate the risk of accidents caused by unintentional vehicle movement.