QCVN 41 — National technical regulation on road signs and signals

QCVN 41 — National technical regulation on road signalling is the source for the whole "Road signs" chapter of the theory test. Every sign question traces back to it.

Order of precedence

When several kinds of signalling conflict, obey them in this order:

1. Instructions of the traffic controller;
2. Traffic lights;
3. Road signs;
4. Road markings and other marks on the carriageway.

This is one of the most frequently asked questions in the test, and an everyday rule whenever an officer directs traffic at a signalled junction.

Five sign groups

• Prohibitory signs — round, red rim, white face: forbid or restrict.
• Warning signs — yellow triangle with red rim: warn of a hazard ahead.
• Mandatory signs — round, blue face: must be obeyed.
• Information signs — rectangular/square, blue face: provide information.
• Supplementary plates — mounted with a main sign to qualify its meaning.

This is a quick-reference summary. Always check the original legal document before relying on it — editors keep this article up to date in the CMS.