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A Red Arrow Should Mean Something

What a traffic light reveals about communication design, legal rules, and the cost of ambiguity.

Jackie LiuSeptember 30, 20264 min read

I first noticed this years ago in Kansas, on a drive I made all the time.

When I wanted Asian groceries, I often went to 888 International Market in Overland Park, just off US-69 on W 119th Street. Somewhere along that route, I kept running into the same puzzle: a dedicated right-turn lane with a red arrow.

I would stop and wait.

Other drivers often did not. They would stop, check traffic, and turn. Sometimes the driver behind me would honk.

My logic seemed obvious. A normal red light means stop, and in much of the United States you may turn right after stopping if the way is clear. But a red arrow looked more specific. To me, it meant: this direction is closed.

For years I assumed other drivers were simply ignoring the rule.

Then the same thing followed me to Indianapolis. Recently, driving back from Walmart past Lucas Oil Stadium, I stopped again at a red right-turn arrow. Other drivers treated it like an ordinary red light: stop, look, turn. Sometimes waiting earned another honk.

So I finally looked it up.

In Indiana, the other drivers were often right. State law and the Driver's Manual allow a right turn after a full stop at a red light or red arrow when the turn is otherwise permitted and no NO TURN ON RED sign is present.

Kansas is even messier. The Kansas Driver's Handbook says a red arrow means stop and do not proceed until a green arrow or light appears. But K.S.A. 8-1508 groups a steady circular red and a red arrow together, then says traffic facing a “steady red signal” may turn right after stopping unless a sign prohibits the turn. The statute does not expressly limit that exception to circular red signals.

So even within Kansas, the handbook and the statute do not communicate the rule the same way.

That also answers the obvious reaction: “How did you pass your driving test?”

By learning the rule from the official handbook. If the handbook and the statute point drivers in different directions, this is not simply a failure to learn the rules.

Same color. Same shape. Different action—and sometimes different answers from the same state.

That is a communication-design problem.

Traffic signals are law translated into an interface. Their job is to tell ordinary people what to do in seconds. Red means stop. An arrow specifies a direction. Put them together, and “stop this direction” is an entirely natural reading.

But in Indiana, the visible message is incomplete. To know what the arrow actually allows, I also need a jurisdiction-specific exception: stop first, then you may still turn right unless a sign says otherwise.

That creates a cost. The public has to remember a hidden exception, look up the rule, or learn from watching other drivers. Once people start honking, the ambiguity becomes social pressure: the person trying to obey the signal feels like the one doing something wrong.

Law cannot always be intuitive. But traffic control is public-facing legal communication designed for immediate compliance. If the operative rule is counterintuitive, the exception should be visible at the point of decision.

Otherwise the system teaches a bad meta-rule:

Do not trust the sign; there may be another rule behind the rule.

That is bad for legal literacy. Public legal communication should reduce uncertainty, not train people to second-guess apparently clear instructions.

The irony is that the system already has a very clear message: NO TURN ON RED. In Indiana, those words remove the right-on-red exception. But that raises the obvious design question:

If a red arrow does not already mean “do not turn in this direction,” what exactly did the arrow add?

The Federal Highway Administration (FHWA), which publishes national highway-design and traffic-control guidance, has noted in its human-factors work that red right-turn arrows are often misunderstood. Some drivers read them as an absolute prohibition; others read them as an ordinary red light that still permits a turn after stopping.

That is exactly the problem.

A symbol can be legally defined and still communicate badly.

If I have to remember which state I am in—or, in Kansas, which official document I am reading—before I know what the same red arrow means, the law may still be precise.

The communication is not.

A traffic signal should not be a footnote to a statute.

It should be the message.