What type of sign would typically indicate that parking is not allowed?

Regulatory signs are crucial in enforcing laws and regulations that drivers must follow on the road. They are designed to control the behavior of drivers and pedestrians to ensure safety and compliance with traffic rules. A sign that indicates parking is not allowed falls into this category since it mandates a specific action (or inaction) from drivers, effectively regulating how vehicles are parked in a given area.

Parking restriction signs often display clear, concise messages and symbols that convey to motorists that they are prohibited from parking in that location, enhancing both traffic flow and safety in busy areas. The use of such signs helps prevent congestion, ensures access for emergency vehicles, and maintains order on the streets.

While informative signs provide useful information and warning signs alert drivers to potential hazards, they do not enforce legal obligations. Similarly, traffic control device signs are broader in scope and can include different types of regulations but do not specifically focus on prohibiting parking. Thus, regulatory signs are the correct answer in this context since they specifically indicate parking restrictions that drivers must abide by.