What is one purpose of requiring registration papers on trucks at all times?

Requiring registration papers on trucks at all times serves several important functions, one of which is to provide information regarding the empty weight of the truck. This data is crucial for various reasons, including compliance with weight regulations and safety standards on the road. The empty weight directly affects how much cargo the truck can carry legally, ensuring that it does not exceed weight limits enforced by law. Keeping registration papers on hand allows law enforcement and regulatory agencies to verify this information quickly if necessary.

Other options do not align with the primary purpose of registration papers. For example, showing purchase price would not typically be found on standard registration documents, and the vehicle color, while it may be listed, is less pertinent in terms of regulatory compliance. Similarly, while the driver's information can be important for identification and liability, it is not the main reason for maintaining registration papers in the vehicle.