What is the maximum speed limit for a heavy truck, without a trailer, on motorways and clearways?

A heavy truck without a trailer is allowed to drive at a maximum speed of 90 km/h on motorways and clearways and at a maximum speed of 80 km/h on other roads.

A heavy truck with a trailer is never allowed to exceed 80 km/h, regardless whether the road is a country road, motorway or clearway.