What are T routes used for?

T routes, or "Typed routes," are specifically designed for use in the U.S. airspace system to facilitate navigation for aircraft operating under Instrument Flight Rules (IFR) at lower altitudes. They apply to RNAV (Area Navigation) operations and are utilized primarily from 1,200 feet above ground level (AGL) up to, but not including, 18,000 feet mean sea level (MSL). These routes help streamline air traffic control by providing clear and efficient paths for aircraft flying at lower altitudes, optimizing safety and efficiency in crowded airspace where conventional airways might not be as effective.

Additionally, T routes support the RNAV system, which allows aircraft to navigate without relying solely on traditional ground-based navigational aids, thus enhancing operational flexibility and precision in flight planning and execution.