At what maximum speed are you allowed to drive on the road beyond this sign if you are driving a lorry of gross vehicle weight rating over 3.5 tons?

The visible D-7 'expressway' sign indicates entry onto this type of road. In accordance with the provisions of the Road Traffic Act, the maximum permissible speed for a heavy goods vehicle with a maximum authorised mass exceeding 3.5 tonnes on an expressway and a motorway is 80 km/h.