If you’re driving a car, it’s always the cyclist’s fault. If you’re the cyclist, it’s always the driver’s fault. But what if it’s neither of your faults, and you’re simply misunderstanding each other?
In a study published late last year in the journal Accident Analysis & Prevention, researchers investigated how well drivers understood bicyclists’ hand signals, and let’s just say that sometimes it was like they spoke two different languages. The research is timely. More cyclists are sharing roads with drivers, raising the risk of crashes from simple miscommunication. In the U.S., cyclist deaths in traffic accidents have increased by 38% over the past decade.
“Confusion around cyclist hand signals could lead drivers to react too late or make a maneuver directly into a cyclist’s path,” Christine Petersen, lead author of the study and a researcher at Rice University, said in a university statement. “Cyclists are required by law to use hand signals, but we don’t really know whether those signals consistently help drivers understand what a cyclist is about to do.” On the other hand, we know a lot more about the dynamics between pedestrians and drivers.
Within that context, Peterson and fellow Rice University researcher Patricia DeLucia tested study participants’ ability to determine a bicyclist’s next move. No, not within a real driving context, you psycho. The “drivers” watched videos of a cyclist delivering sets of indications (arm signals, head movement, and position on the road) and reported what they thought the cyclist would do next (go left, go right, stop, or keep straight).
Arm signals for the win
Unsurprisingly, the drivers mostly used arm signals to understand the cyclist’s forthcoming action (this video from the League of American Bicyclists goes over the standard arm signals). Other indications you might think are effective, like if cyclists look over their shoulder or where they are on the road, didn’t do much for the drivers’ understanding.
Most drivers comprehended left or right turns communicated by a straight arm indicating left or right. The bent-arm sign, however, proved trickier. Would you have understood it? It legally indicates a right turn in a significant number of places, and not even 25% of the drivers understood it. Thankfully, a majority of the drivers understood the stopping or slowing sign. However, when presumably asked what signal they themselves would employ as cyclists to communicate stopping or slowing, a significant number of drivers reported a different sign.
“Signals that match the direction of movement, pointing where you’re going, are especially important for keeping interactions predictable and safe,” explained Petersen. “Hand signals matter, but clarity matters even more.”
It also doesn’t help that, according to the study, the rules and expectations associated with gestures are not the same in every country, even though the gestures themselves are comparable.
Don’t get distracted
The researchers employed eye-tracking as well, which showed that drivers first concentrated on the cyclist’s back, maintaining them completely within view. When the cyclist moved their head or arm, the driver’s focus went to the movement, actively seeking revealing indications. Still, they dedicated a lot of time regarding the cyclist’s face, probably trying to verify their plan with eye contact.
“Drivers aren’t ignoring cyclists,” Petersen said. That’s for you cyclists who think drivers are purposefully pretending like you’re not there. “They’re trying to read them.”
Unsurprisingly, when the drivers took part in a pretend cellphone call, the accuracy of their predictions decreased despite the fact that they were still looking at the road. They were still most likely to correctly interpret arm signals but did worse in general.
“Distraction isn’t just about looking away,” Petersen said. “Talking on a cellphone can slow reaction time and make it harder to process what a cyclist is trying to communicate,” she added. “Cyclists are already at a disadvantage” because they don’t have many of the visual signals that drivers use to understand car movement, like bright turn signals and brake lights. This worsens the risks associated with distraction. “When a driver isn’t fully attentive, misunderstanding becomes more likely.”
Keep using them
While the results cast doubt on whether established traffic laws completely align with the way people think in such moments, Peterson says the legal hand signs—though clearly not perfect—remain the safest method for cyclists. For the moment, that is. Laws can improve. For example, the study emphasizes that more comprehensible and natural stopping or slowing indications, a.k.a. when drivers who really, really need to understand you, are necessary.
“Research gives us an opportunity to rethink communication and invest in better education, so drivers and cyclists understand each other,” said Peterson. “When communication breaks down,” she concluded, “the risks increase for everyone.”
