Slow-Moving Vehicle Sign
Marks a vehicle that travels 25 mph or less; slow down and use caution.
What it looks like
A fluorescent orange triangle with a dark-red reflective border, an ANSI/ASAE emblem mounted on the rear of a slow vehicle rather than a roadside sign.
When you'll see it
On the back of farm tractors, horse-drawn buggies, and other vehicles that travel 25 mph or less, most often on rural roads.
What to do
Slow down and use caution as you approach; be ready to reduce speed well in advance and pass only when it is safe and legal.
Related signs
Source: Manual on Uniform Traffic Control Devices (MUTCD), 11th Edition — FHWA.