Road Rules: Turn signals in emergency


Question: What does the law say about using turn signals while needing to perform an emergency maneuver?  For example, if I must avoid a head-on collision requiring a spontaneous and immediate response, am I breaking the law if I do not use a turn signal at this moment?  

Answer: Right now a bunch of BMW drivers are confused by this question. They’re asking themselves, “How can turn signals possibly be required in an emergency? I didn’t think they were even required for ordinary driving.”

The great driving instructor Archilochus once said that under pressure, “We don’t rise to the level of our expectations, we fall to the level of our training.” Okay, he wasn’t a driving instructor, he was a Greek poet from 650 BC. He’s not wrong though. 

When we get into a high-pressure situation, like coming face-to-face with a lion (not uncommon in Archilochus’ time and place), our bodies prioritize our blood flow to the parts of us that can help us either run away from or, the much worse option, fight the lion. We have a fixed amount of blood, so when more goes to our muscles, less goes to our brains. The prefrontal cortex (the part that does our higher-order thinking) takes the biggest hit. When facing a lion, we can afford to give up a bit of abstract thinking if it means we can run faster. But if you’re engaged in a task that requires complex analysis of a rapidly changing environment, that’s not so good.

What does a long-dead poet and our prefrontal cortex have to do with turn signals in an emergency? 

Even though Archilochus didn’t know the science behind it, he correctly recognized that when confronted with a threat, we don’t think as clearly and we’re going to depend more on our past practices. If you’re the kind of person who always uses your turn signals, there’s a good chance that in an emergency you’re going to instinctively use your signals without even realizing it.

But if you don’t, have you broken the law? Eh, probably. The law states, in part, that “No person shall turn a vehicle or move right or left upon a roadway without giving an appropriate signal.” There’s no clause indicating it doesn’t apply in emergency situations. 

However, the law also requires drivers to signal at least 100 feet before turning, and that’s likely not an option in an emergency. If it’s impossible to both comply with the law and avoid a crash, maybe the law doesn’t apply here, or at least, that’s what I’d tell the judge.

I have no enforcement authority, but I’m confident that the police are not going to get worked up about turn signal rules if you didn’t use your blinker while swerving to avoid a head-on collision. I’m so confident that I’ll buy a coffee for the first person who can send me evidence that they got an infraction for failing to signal while they were making an emergency maneuver to avoid a crash. 

Traffic laws aren’t suspended in the moments leading up to a potential crash, but when considering enforcement, police look at the totality of the circumstances. If you swerve to avoid a crash, but don’t use your turn signal, an officer is under no obligation to take enforcement action.

Let’s take Archilochus’ concept beyond turn signals to other safe driving behaviors, like scanning your surroundings, maintaining a safe following distance, checking your speed, identifying an escape route, and minimizing distractions. If you practice them in low-pressure situations, they’ll be there for you in the critical moments. 

Doug Dahl is a manager with the Washington Traffic Safety Commission, Region 11 and publishes


No comments on this item Please log in to comment by clicking here