You’re probably used to seeing red stop signs with white lettering at every intersection—but what if you came across a blue one? While it may seem like a mistake or a prank, blue stop signs do exist, though they aren’t part of official traffic control. These signs are typically used on private property such as gated communities, school campuses, or large parking lots.

In the United States, all official road signs must follow federal regulations, which require stop signs to be red. The color red is chosen because it signals urgency and commands immediate attention. A blue stop sign doesn’t meet these federal standards, which means it’s not legally enforceable on public roads.

Despite their unofficial status, blue stop signs still carry the same meaning—drivers are expected to stop. Private property owners install them to manage traffic within their areas, and ignoring them could still result in collisions or penalties enforced by local property rules. So while they’re not backed by law, they serve a practical purpose.

Other unusual stop signs also exist, such as bilingual signs in Canada or LED-lit versions in high-traffic areas. If you see a blue stop sign, it’s smart to treat it just like a regular one. It might not be government-issued, but stopping could keep you—and others—safe.