Originally posted in 2004 (with revisions 2009)

A safe method to controlling airspace for the gyroplane would be to use a compass* heading to define altitude position.
Each degree of the compass would specify a precise altitude.
This keeps gyroplanes at a safe distance in the vertical dimension.

For instance: every gyroplane flying west would travel at 2400 feet, gyroplane travelling in a Northwest direction would fly at 2200 feet, and every gyroplane travelling north would fly at 2000 feet etc. So the simple compass could be used to regulate altitude for gyroplane in the air, plus the use of Automatic Dependent Surveillance - Broadcast (ADS-B) computers.

Henry Ford* expected we would be drive-flying before the end of the 20th century. Let's carry this concept for gyroplane travel for the 'masses' to a practical and ordered view point.

"How would a gyroplane move safely between levels?"
Say you were flying Southwest at 1000 ft. You arrived at a point where you needed to change course to flying East. That flying level is 1600 ft. So you would proceed upwards through South East and East in a long left hand curve. This puts you facing the proper direction of travel as you move through levels to reach East and you arrive at that level travelling in the proper direction. Any other air traffic would be able to tell at a glance that you were going to move upwards by a slow arc (curve) to the left. You are a predictable object they can adjust to because you are conforming to Seelevels.
Similarly in changing course direction from West to South West you would move downwards by making a slow curve to the right as you move down through North West level and North level to get to South level and be flying in the proper direction when you arrive at 1000 ft.
Therefore, course changes that require moving to a higher altitude would always be on a slow left hand curve through flight levels. Course changes that require moving to a lower altitude would always be on a slow right hand curve through flight levels.
(Safety comes from making slow corrections and slow predictable changes in altitude and direction for other pilots to recognise.)
You can see by the levels chart that alternately to fly South West from West you could move up one level to South West, if terrain does not permit 1000 ft level, such as in mountainous areas.

"Okay, sure, but what if I needed to fly NNE not North or North East. What then?"
No problem you would then fly at an altitude of 1900 ft. The safety is flying at an altitude where others can see you ahead and approach you to pass at a slower closing speed than if they were coming towards you. It's easier to make adjustments when over taking and passing.
The idea is to eliminate situations where aircraft are flying towards each other in the same altitudes.

It's important to establish the Compass Levels Altitude System (Seelevels)*2 before growing numbers of gyroplane fill the sky's. This provides a simple, reliable "sky-road" of courtesy to make sky travel safe and predictable.