The **maximum speed** for a **special vehicle** on **roads** is **40 kilometers per hour**. This applies to special vehicles that do not have a trailer or semi-trailer and are not classified as power tillers or vehicles without brake lights. The latter have a different maximum speed, of 25 km/h, as mentioned in another context. Additionally, special vehicles cannot travel on highways and expressways.


Therefore, for special vehicles without additional restrictions, the maximum permitted speed on roads is **40 km/h**.