On a road marked this way, can you drive a light four wheeled vehicle (microcar, quad)?

The legal basis points to the D-9 'motorway' sign, which indicates entry onto a road intended exclusively for motor vehicles capable of developing a speed of at least 40 km/h (according to Art. 2 pt. 3). A light quadricycle, whose design speed is limited to 45 km/h, is not allowed on such roads for reasons of safety and traffic flow.