What is the maximum speed at which the driver of the intercity bus can move in this situation?

Explication

The road is outside a built-up area and no speed-limit sign restricts it, so the intercity bus keeps its class ceiling of 90 km/h. The green route board names a route and destination rather than setting a speed; 60 km/h is the built-up-area figure, and the other lower figures do not govern here.