The sign you referred to is known as the Notice of altered right of way, traffic management, or special traffic regulations (sign number 1008-34).

This sign indicates that there are specific traffic regulations or a change in the normal right of way rules at the location where the sign is posted. It's often used to inform drivers of temporary changes due to construction, events, or other situations that may affect traffic flow.

When you see this sign, it is important to pay close attention to additional instructions or signals that may be present, as they will guide you on how to proceed safely and responsibly. Always be prepared to adjust your driving according to the modified rules indicated by the sign.

If you have any further questions about this sign or other traffic rules, feel free to ask!