What must a person operating a bike, sled, or roller-skates not attach to their vehicle?

A person operating a bike, sled, or roller-skates must not attach certain items to their vehicle because these attachments can create safety hazards or affect the stability and control of the vehicle. In many jurisdictions, specific regulations prohibit attaching items that can interfere with the operator's ability to steer, balance, or maneuver effectively.

Bicycles, sleds, and roller-skates are designed for a specific range of use and handling, and adding certain attachments can compromise the safety of the rider as well as those around them. For instance, a bike trailer may be permissible but only under specific conditions and in designated areas. However, in this context, the assumption is that such attachments are broadly prohibited due to the potential for accidents.

When it comes to safety flags or reflective gear, while these items can be important for visibility and safety, they do not typically fall under the category of items that would compromise the operator's control over their vehicle. Therefore, it's crucial for riders to adhere to regulations that promote safe riding conditions, and that often includes avoiding unauthorized attachments. This emphasis on safety justifies the answer that all listed items should not be attached while operating these types of vehicles.