You are allowed to stop on a priority road to load or unload goods, to allow a passenger to get in or out of the car, to avoid danger (for example, if an animals runs across the road) or if traffic conditions so require (for example, if there is a traffic jam).

There is, however, a general parking prohibition on priority roads, which means that you are only allowed to park in marked parking spaces.

Read more about stopping and parking on country roads