What is prohibited for persons riding the bus?

Riding without a shirt or shoes is prohibited because it is considered a matter of basic public decency and hygiene. Public transportation systems maintain specific guidelines to ensure a comfortable and acceptable environment for all passengers. By requiring riders to wear appropriate clothing, transit authorities aim to create a respectful atmosphere and uphold community standards. This policy also aligns with health regulations that dictate a minimum standard of attire for public spaces, ensuring that everyone can travel without discomfort or offense.

The other options involve behaviors that may be discouraged or regulated but do not carry the same level of public health and decency implications as not wearing a shirt or shoes. For instance, using cell phones might be allowed with respectful discretion, and carrying large bags could be regulated for safety and space reasons, but they do not directly compromise the basic standards of public conduct in the same manner.