Which of the following may be lower than the published MEA?

The Minimum Vectoring Altitude (MVA) may be lower than the published Minimum En Route Altitude (MEA) because it is specifically determined for radar vectoring within controlled airspace to ensure safe aircraft operation while allowing for more efficient routing of traffic. The MVA is set to accommodate the minimum safe altitude over terrain and obstacles within a specific area while using radar to provide vector services to aircraft.

The MEA, on the other hand, is established for specific routes and is designed to provide adequate terrain clearance and signal coverage on airways. While MVAs are adjusted for the nuances of radar traffic management, they can be lower than MEAs since they reflect local requirements rather than broader routing specifications.

In contrast, the Minimum IFR Altitude and Minimum Safe Altitude are typically defined to ensure safety and obstacle clearance and are influenced by factors that maintain established vertical separations from terrain and man-made structures. The Minimum En Route Altitude is also established as the lowest altitude to be flown to ensure adequate clearance along the route but does not directly account for specific vectoring needs managed by air traffic control.