What distinguishes an air route from an airway?

The distinction between an air route and an airway primarily revolves around control and management of the airspace. An air route is generally understood to be less regulated and can allow for more flexibility in navigation, often utilized by pilots who may not be within controlled air traffic systems. In contrast, an airway is a designated route in the airspace that is subject to more stringent control measures, often managed by air traffic control to ensure safe and organized air traffic flow.

In controlled airspace, airways provide structured navigation and are often used by commercial and other flight operations that require separation from other traffic. These routes are essential for maintaining safety and efficiency in busy air traffic environments. Uncontrolled air routes offer pilots the ability to navigate more freely, independent of air traffic control, typically used in less congested or remote areas.

Given this understanding, the answer aligns with the definitions of air route and airway regarding their control and operational practices in aviation.