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?
The 18 t stated as permitted maximum mass on your registration certificate
The 13 t the weighbridge showed today for the whole truck
The 9 t the weighbridge showed today on the most heavily loaded axle
Explanation
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. Book p.239-240.