These 3 signs belong to the prohibition sign with auxiliary sign, the auxiliary sign shows what vehicle is prohibited.
Signal 1 is prohibiting cars (all motor vehicles are prohibited including 3-wheeled motorcycles with a passing box, except for two-wheeled motorcycles, mopeds and priority vehicles).
Signal 2 is prohibited for motorcycles
Section 3 is prohibited for trucks ( type from 1,5 tons or more, including tractors and special-use motorcycles)