Is a “restricted vehicle” permitted to use a road in which the following traffic sign is placed?

1. Yes, driving at a minimum speed of 55 k.p.h.
2. Yes, driving at a maximum speed of 55 k.p.h.
3. Yes, on a freeway only.
4. Correct answer: No.

WhyA blue circle with the number 55 means a road for those who can and may drive at least 55 KPH. Slow vehicles may not use it.