On a **motorway**, parking is only allowed in **specifically designated areas** for this purpose. This is because motorways are designed for the fast and safe transit of vehicles, and any stop or parking outside the designated areas can pose a danger to road safety.

- **Emergencies**: If a vehicle has an emergency, such as a breakdown, it must stop on the **hard shoulder** or in the **central reservation** only temporarily and not for parking. This is only for emergency situations and not for regular parking.

- **Safety**: Parking in undesignated areas, such as the central reservation or the hard shoulder, can obstruct the flow of traffic and increase the risk of accidents. Therefore, it is crucial to use only the designated spaces for parking on a motorway.

In summary, to ensure safety and the proper flow of traffic, it is essential to park only in the designated areas on a motorway.