What are 'airspace restrictions' for RPA?

Airspace restrictions for Remotely Piloted Aircraft (RPA) are primarily about safety and the need to avoid conflicts with other aircraft. These restrictions specify certain areas where RPA operations are either limited or prohibited to ensure the safety of all airspace users. This may include airspace near airports, areas where emergency response operations are taking place, or zones used for military activities.

The reason this choice is the best answer lies in the essence of airspace management which balances the needs of various aviation activities to prevent accidents and ensure that all aircraft can operate safely. These restrictions often include altitude, but they are more comprehensive because they encompass specific geographical locations and conditions that limit RPA operation.

The other options fail to fully represent the broader and essential nature of these restrictions. While altitude limitations may be part of the restrictions, they do not provide a complete picture. Common routes may exist for manned aircraft but do not necessarily apply to RPA in the same way. Designated areas for experimental flights refer to specific permissions or tests rather than broad airspace restrictions.