The study, led by Christine Petersen, a doctoral student in psychological sciences at Rice University, explored how drivers interpret cyclist hand signals. Petersen also reviewed traffic laws in different countries and found similarities but no uniform rules or expectations.
Researchers placed participants in realistic driving scenarios and asked them to predict whether a cyclist would turn left, turn right, stop or continue straight. Each scenario combined three cues: arm signals, head movement and the cyclist's road position.
Results showed drivers relied overwhelmingly on arm signals. Lane position and a glance over the shoulder did not significantly improve prediction accuracy. Eye-tracking data indicated drivers first looked at the cyclist's back, then shifted attention to arm or head movement, and often checked the cyclist's face to confirm intent. Straight-arm turn signals were almost universally understood, but fewer than a quarter of drivers correctly interpreted the bent-arm right-turn signal. Simulated cellphone conversations reduced prediction ability, though arm signals remained the best cue.
Difficult words
- interpret — understand the meaning of an action
- predict — say what will happen before it happens
- cue — a sign that gives information to a personcues
- eye-tracking — method to record where people look
- lane — part of the road for vehicle travelLane position
- intent — a person's plan or reason to act
- simulate — make something seem like the real thingSimulated cellphone conversations
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Have you seen cyclists use hand signals where you live? Do drivers usually understand them?
- What could drivers and cyclists do to improve communication and reduce mistakes on the road?
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