According to MUTCD, the types of signs used on American roadways are categorized as what?

The categories of signs used on American roadways, as defined in the Manual on Uniform Traffic Control Devices (MUTCD), are indeed classified into three main types: Regulatory, Warning, and Guide.

Regulatory signs are critical because they inform drivers of laws and regulations that must be followed, such as speed limits and no entry signs. Warning signs serve to alert drivers to potential hazards or changes in road conditions ahead, ensuring they can take appropriate actions to maintain safety. Guide signs provide information that aids navigation, including directions to places, distances, and other pertinent information travelers need to make informed decisions while driving.

This classification reflects the fundamental role each sign type plays in aiding traffic flow and ensuring the safety of all road users. The other options misrepresent the MUTCD framework, as they include incorrect groupings or terminology that does not align with the standardized definitions of traffic signs.