Here’s What It Means If You See a Blue Stop Sign

In a world of confusing road signs, there’s one that’s never hard to figure out: STOP. Way before driver’s ed, we all knew the key details about its shape and what to do when you saw one. Heck, even a toddler can tell you that stop signs are red. That’s because since the 1950s, red has been the required background color for all government-regulated stop signs in the United States.

But you might be surprised to learn that in the early days of automobile traffic, yellow stop signs were prevalent. Weird to think about in retrospect, right? But even more of an oddity is the elusive blue stop sign. Yes, they exist, and if you’ve never seen one, you might do a double-take. But where are they found, and what does a blue stop sign mean? (You know, aside from stop?)

To get to the bottom of this traffic-control anomaly, we asked Shashi Nambisan, PhD, director of the Transportation Research Center at the University of Nevada, Las Vegas, and Nathan Kautz, a senior transportation safety engineer with Kittelson & Associates, a transportation engineering and planning consulting firm. Here’s what they had to say.

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Why are stop signs typically red?

There are a few reasons. First, red is the easiest color to see from the farthest distance. This gives drivers plenty of time to identify the stop sign and slow down. Second, red is often associated with danger, telling you to proceed with caution. That’s why car brake lights and traffic lights are red, and the same is true of stop signs.

In the U.S., “the shape and colors of signs (including stop signs) are identified in a document known as the Manual on Uniform Control of Traffic Devices (MUCTD),” Nambisan says. It was in 1954 that the MUCTD codified red stop signs with white lettering, moving away from the aforementioned yellow background after advancements in fade-resistant finishes helped with nighttime visibility.

What is a blue stop sign?

A blue stop sign is a blue and white octagonal sign that indicates you should make a full and complete stop before driving again. It functions just like a red one—it just happens to be blue.

The difference between blue stop signs and red stop signs comes down to where they can legally be installed and where in the country you’re most likely to spot them.

Where can you find blue stop signs?

Blue stop signs are installed on private property. Think: ranches, golf courses, large estates and other private lands that have roads that need traffic control. Because official stop signs must be red with white letters, you won’t see blue stop signs at public intersections. “To the best of my knowledge, blue-colored stop signs are not permitted on public roads,” Nambisan says.

Which brings us to Hawaii. If you’ve been to the Aloha State or talked to people who go there regularly, you’ve probably seen or heard about the islands’ ubiquitous blue stop signs. So does Hawaii have different official traffic rules or something? Nope. It comes down to the state’s history of private land ownership.

Currently, 37 people (billionaires, to be exact) own more than 218,000 acres, or about 11% of Hawaii’s total landmass. Historically it was even more skewed, with 18 people owning 40% of the state’s total acreage back in the 1960s, according to a 1984 U.S. Supreme Court opinion that addressed the constitutionality of the state’s attempts to use eminent domain to democratize land ownership in the state.

So while you can find blue stop signs elsewhere on private property across the U.S., the high concentration of large, privately owned ranches, estates and farms in Hawaii explains why blue stop signs are most common there.

Is it mandatory to follow blue stop signs?

It depends on where you live.

In Hawaii, the state can enforce traffic laws on private roads, but there are exceptions for primarily agricultural and ranching roads. In Ohio, owners of private roads may place stop signs as needed, but they must inform visitors (via another sign) that they are entering private property, that they must stop for the signs and that they are subject to enforcement under state law. Tennessee differentiates between private property with public rights of way and completely private areas. Other states likely have laws specific to their own history and enforcement capabilities.

That said, even if you’re not going to get arrested for rolling through a blue stop sign, stopping is definitely a good idea—for your safety and the safety of others. “While not a legal expert, I imagine that most people would treat a blue stop sign the same as they would a red stop sign if they encounter one,” Kautz says.

So when you approach one, treat it like you would before you learned anything about blue stop sign meanings: Stop.

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At Reader’s Digest, we’re committed to producing high-quality content by writers with expertise and experience in their field in consultation with relevant, qualified experts. We rely on reputable primary sources, including government and professional organizations and academic institutions as well as our writers’ personal experiences where appropriate. For this piece on blue stop signs, Kelly Bryant tapped her experience as a longtime journalist who often covers interesting facts and trending topics for Reader’s Digest. We verify all facts and data, back them with credible sourcing and revisit them over time to ensure they remain accurate and up to date. Read more about our team, our contributors and our editorial policies.

Sources:

• Shashi Nambisan, PhD, director of the Transportation Research Center and professor in the Department of Civil and Environmental Engineering at the University of Nevada, Las Vegas; interviewed, November 2024
• Nathan Kautz, senior transportation safety engineer with Kittelson & Associates; interviewed, November 2024
• Federal Highway Administration: “The Evolution of MUTCD”
• Justia: “Hawaii Housing Authority v. Midkiff, 467 U.S. 229 (1984)”
• Hawaii.gov: “Hawai’i property ownership: Its history and potential future implications”
• Justia: “2024 Hawaii Revised Statutes: Traffic regulation and control over private streets”
• Ohio Laws & Administrative Rules: “Section 4511.432 | Stop signs on private road”
• Justia: “2024 Tennessee code: Enforcement of traffic laws on certain privately owned streets”

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