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

To prevent a two-axle truck from rolling down a steep slope, it is essential to engage the parking brake and place a wheel chock under a rear wheel.

Engaging the parking brake is a fundamental requirement as it secures the vehicle in place when stationary. The wheel chock acts as an additional safety measure by physically blocking the wheel from moving.

While applying the retarders can help slow down the vehicle during descent, it does not provide the same level of security as the other two measures when the vehicle is stationary. German traffic regulations emphasize the importance of proper vehicle securing measures to prevent accidents, particularly on steep inclines, where the risk of rolling is higher. Therefore, both the parking brake and wheel chock are necessary to ensure safety in this scenario.