Vietnamese riders communicate constantly — with horns, indicators, and hands. Hand signals are part of the local riding grammar: not legally required replacements for indicators, but real signals with real meanings.
The working vocabulary
Left arm out and pointing left: turning or changing lanes left. Right arm out, palm forward: turning or drifting right — pointing with the right arm is common in Vietnam even though left-arm signals mirror a car’s vocabulary elsewhere. A flat palm pressed downward, repeated: slowing down, often from the lead rider of a group toward followers. An open palm held high or waving: hazard awareness, “careful ahead”, used around buses, potholes or a queue’s end.
When hands matter most
Group rides, where one rider sees the hazard first — visibility-riding-motorbike-vietnam covers making sure the group sees you. Broken indicators: the law requires working lighting and signalling equipment — motorbike-required-equipment-vietnam covers the legal list — and a hand is the honest backup for a dead bulb. In rain and dusk when indicator lights wash out, an arm out early is visible when a blinking amber is not.
The limits
Signals do not create priority. An arm out is an intention, not a permission slip: still check behind before moving, still assume the bus has not seen you. Filtering past a queue, an arm alone will not stop a car door — filtering-through-traffic-motorbike-vietnam covers that craft.
To passengers and children
A pillion can hold a bag while the rider signals; agreeing on that before moving is part of the pillion briefing in balancing-pillion-riding-motorbike-vietnam.
The one-line version
Point where you are going, palm down for slowing, a wave for hazards — learn the local vocabulary, but keep the indicators working and never treat a hand as a right of way.