Final answer:
The Manual on Uniform Traffic Control Devices (MUTCD) regulates the shape, color, and location of road signs in the United States, providing standards that are enforced by state and local authorities to ensure consistent traffic control and enhance highway safety.
Step-by-step explanation:
The Act that regulates the shape, color, and location of road signs in the United States is the Manual on Uniform Traffic Control Devices (MUTCD). This manual is published by the Federal Highway Administration (FHWA) and sets the standards for all traffic control devices, including road signs, traffic signals, and pavement markings. States and local jurisdictions follow the MUTCD to ensure consistency and familiarity for drivers, which is essential for highway safety.
State police have the authority to enforce these standards on a statewide basis, while local or county police jurisdictions are responsible for enforcing them within their respective areas. The MUTCD's guidelines help maintain uniformity across all states, thereby reducing confusion among drivers and enhancing road safety.