Road for motor vehicles that are permitted and capable of driving at least the speed indicated in the sign (in k.p.h)

What is the meaning of the following traffic sign?

1. It is forbidden to exceed the speed indicated in the sign (in k.p.h).
2. Correct answer: Road for motor vehicles that are permitted and capable of driving at least the speed indicated in the sign (in k.p.h).
3. Speed limit of 55 k.p.h.
4. It is forbidden to drive slower than the speed indicated in the sign (in k.p.h).