Slow moving vehicle

The slow-moving vehicle sign was created by William J. Fletcher, amongst others, from the National Safety Council.

The United States Department of Transportation as well as various Canadian provinces have established regulations that dictate the minimum required size of the sign, and grant exemptions for displaying the sign for certain religious groups having an objection to displaying a sign, which are operating horse-drawn carriages or wagons on public highways, provided they use an alternative reflective marking on the rear of the wagon or carriage.

In the United States, slow-moving Vehicle Emblem Requirements are defined in the 29 CFR 1910 Occupational Safety and Health Administration .145(d)(10) regulation.

Indeed, Vienna convention just defines such as the two red reflex-reflectors for trailers, and prohibits some class of roads or some kind to some moving vehicles not able by design to reach a specific speed defined by domestic legislation, for instance on motorways.

Regulation Unece number 69 address rear marking plates for slow-moving vehicles (by construction) and their trailers.

[7] The mark in the rear vehicle is a "SMV rear marking plate", a triangular plate with truncated corners with a characteristic pattern faced with retro-reflective and fluorescent material or devices (class 1); or with retro-reflective materials or devices only (class 2).