Core: Towing a trailer or caravan: 90 km/u is never 'just always'

The rule for a trailer/caravan follows the same road-type ladder as without a trailer, with one important deviation at the top. Within the built-up area it stays 50 km/u — no difference from the ordinary rule. Outside the built-up area, on an ordinary road, it is 80 km/u — also no difference. On an autoweg or motorway it does NOT become the ordinary sign figure (100 or 130), but a separate, reduced maximum of 90 km/u — and this explicitly applies only if the permitted maximum mass of the trailer or caravan is no more than 3,500 kg. Both conditions must hold at the same time: the right road type AND the right weight. If the trailer's permitted maximum mass exceeds 3,500 kg, the 90 km/u does not apply — you fall back to the ordinary road-type figure (80 outside the built-up area, or lower if a specific sign indicates that). Separately, another special vehicle on the same page: a brommobiel (and a motorised disability vehicle) drives at a fixed maximum speed of 45 km/u, both within and outside the built-up area — no built-up/outside-built-up distinction as with ordinary cars. Figures about trucks and agricultural tractors that sometimes come up with this topic are NOT on these book pages — they are deliberately not taught here until found on a verified page.