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Slow moving heavy vehicles ahead — South African Road Sign W324

Warns that heavy vehicles ahead may be moving slowly, often because of a steep gradient, and could be travelling much slower than the rest of the traffic. Reduce speed, increase your following distance, and only overtake a slow heavy vehicle when you can see it is clearly safe and legal to do so.

Slow moving heavy vehicles ahead road sign

W324

At a glance

Sign code
W324
Type
Warning
Official meaning
Warning of a section of road where slow-moving heavy vehicles are likely to be encountered.

What the Slow moving heavy vehicles ahead sign means

Warns that heavy vehicles ahead may be moving slowly, often because of a steep gradient, and could be travelling much slower than the rest of the traffic.

What you must do

Reduce speed, increase your following distance, and only overtake a slow heavy vehicle when you can see it is clearly safe and legal to do so.

Know the mistake this sign turns on

Full access adds the confusion Slow moving heavy vehicles ahead is most often mistaken for and the hint for the test, on this sign and every other one — plus practice questions and timed mock papers. The practice sample and the readiness test are free.

See the free practice test

Sources

  • Road Traffic Signs chart, National Department of TransportThe official chart. Sign W324 was checked against it, artwork and meaning, before being published here.
  • National Road Traffic Regulations, 2000 — Schedule 1Where the prescribed meaning of each road traffic sign is set out.

Last updated 2026-08-23.

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