Theory Mastery

Sign C21: Closed to vehicles heavier than the mass shown on sign.

C21 – Closed to vehicles heavier than the mass shown on sign.

Series: C -- Closed to traffic

Legal meaning

Closed to vehicles and combinations of vehicles whose total mass exceeds the value indicated on the sign.

Source: RVV 1990 annex 1 · checked 2026-10-23

Shape and colour

Round white sign with a red rim, a black lorry and a number in tonnes: closed to vehicles heavier than that mass.

Where the sign stands

Just before the bridge or stretch the restriction covers, on the right; usually announced at the last turn-off.

What the exam asks about this sign

The question gives the permitted maximum mass or the actual mass of the vehicle and a sign with a number in tonnes. The sign is about the actual mass of the vehicle, load and trailer included, unless a plate says otherwise. Trap: candidates confuse mass with axle load (C20) or think only lorries are meant.

Exam question on this sign

Near Alkmaar you approach, in your truck, a road with sign C21 showing 15 t. Your registration certificate states a permitted maximum mass of 18 t. On the weighbridge today your loaded truck weighed 13 t, of which 9 t on the rear axle. Which weight do you compare with the 15 t on the sign?

  1. The 18 t stated as permitted maximum mass on your registration certificate
  2. The 13 t the weighbridge showed today for the whole truck
  3. The 9 t the weighbridge showed today on the most heavily loaded axle
Show the answer

Correct answer: The 13 t the weighbridge showed today for the whole truck

False — you read C21 as a sign for the mass per axle. A per-axle limit belongs to sign C20; sign C21 is about the total actual mass, the sum of all axle loads.

Why learners get this wrong: Sign C21 looks at the permitted maximum mass on the registration certificate, not at what is actually in the car that day.

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Often confused with

Signs in the same series

Where this is explained

Topics that use this sign

Questions using this

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