What is one reason for covering cargo on an open bed?

Covering cargo on an open bed primarily serves the purpose of protecting the cargo from weather elements. When cargo is exposed to rain, snow, or harsh sunlight, it can be damaged, which may lead to loss of items, degradation of quality, or even safety hazards if materials spill onto the roadway. By covering the load, you help ensure that it arrives at its destination in good condition, which is crucial for maintaining inventory and preventing disruptions in transportation.

The other options may sound plausible in different contexts, but they don't align with the primary purpose of covering cargo. For example, while improving aerodynamics can have benefits for fuel efficiency, it is not the main reason for covering the cargo. Enhancing visibility for other drivers might be a consideration for certain types of loads or securing setups, but it's not the motive behind using a cover. Increasing speed limits is unrelated to the cargo covering and does not play a role in cargo safety or protection.