A left turn across traffic is the most dangerous routine move on any road, and in Vietnam oncoming flows often do not organize themselves into neat lanes. Done with a clear process, it becomes manageable; done by hope, it is where a lot of accidents happen.
Position early, claim your space
As you approach the junction, drift left in plenty of time so your intention is obvious. Signal does not replace position: hands and position communicate more than indicators here. Check your mirror for anything overtaking on your left — it happens constantly.
Read the oncoming stream as a shape, not as cars
You are not waiting for traffic to disappear; you are looking for the natural pulse of gaps that every stream has, especially near lights turning red upstream. Estimate whether you can complete the whole turn — exit lane included — not just reach the middle.
The one-step rule for heavy traffic
If the stream is continuous, cross to the median or centre of the road first, stop parallel to oncoming traffic with your wheel turned toward your exit, and complete the turn in the next gap. Two small crossings are safer than one long exposure. Only do this where there is actual space to wait.
Straighten before you accelerate
Once you are turning, keep the arc wide and steady, then straighten and add throttle. Accelerating while still leaning unsettles the bike — cornering-motorbike-vietnam explains the principle.
Know the rules underneath
Right-turn and lane rules differ from what many foreign licences teach; right-turn-on-red-vietnam and motorbike-lane-rules-vietnam cover the legal baseline. Junction technique overall, including roundabouts, is in roundabouts-motorbike-vietnam.