What safety measure is crucial when working with heavy equipment on a slope?

Engaging the parking brake is a critical safety measure when operating heavy equipment on a slope. This action prevents the equipment from rolling backward or forward unexpectedly, which can lead to dangerous situations, including equipment damage or accidents that could harm the operator or bystanders. On slopes, the risk of gravitational pull can increase the chances of the machine moving if it is not properly secured.

While using lighter materials, working during daylight hours, and performing frequent equipment checks are all important practices in their own right, none specifically address the immediate risk of an unsteady machine on a slope. Engaging the parking brake directly mitigates the danger posed by the slope itself, making it particularly vital for safe operation in such environments.