Traffic signal supports are NOT used to display which of the following items?

Traffic signal supports are primarily designed to hold and display traffic control devices, such as signals, street signs, and regulatory signs, which are essential for managing traffic flow and ensuring safety. Among the choices provided, guide signs are typically used to direct drivers towards destinations or provide information about the road situation, and they are often placed on separate supports specifically designed for that purpose.

While it is possible to see guide signs in some contexts using traffic signal supports, they are not ideal for this application and are more commonly mounted on their own posts or structures to maintain clarity and visibility. The inclusion of advertisements involves a different regulatory framework and is generally not the function of traffic signal supports, as their priority is on traffic safety rather than promotional content.

Thus, the choice indicating guide signs aligns with the understanding that traffic signal supports are not conventionally used for displaying them as part of a traffic control context. The design and purpose of traffic signal supports prioritize official traffic guidance, making this the correct option among those presented.