What position must license plates be in to comply with regulations?

License plates must be mounted in a horizontal and upright position to comply with regulations. This positioning ensures that the plates are easily visible and legible to law enforcement and other drivers, which is essential for identification purposes. A horizontal alignment is standard for most vehicles, as it fits the design of the majority of license plate holders and aligns with the intended visibility for registration and regulatory compliance.

Additionally, having the plate in an upright position also helps to prevent obstructions from dirt, debris, or other materials that may accumulate and obstruct the view of the plate. Both aspects—horizontal alignment and upright positioning—contribute to proper display and recognition of the license plate, thus ensuring that it meets state requirements.