fixes on VOR airways, off-airway routes, or route segments  that meets obstacle clearance requirements for the entire  route segment. [Figure 2-58] This altitude also assures  acceptable navigational signal coverage only within 22 NM  of a VOR. The MOCA seen on the en route chart may have  been computed by adding the required obstacle clearance  (ROC) to the controlling obstacle in the primary area or  computed by using a TERPS chart if the controlling obstacle  is located in the secondary area. This figure is then rounded  to the nearest 100 foot increment (i.e., 2,049 feet becomes  2,000, and 2,050 feet becomes 2,100 feet). An extra 1,000  or route segment. [Figure 2-57] It is the highest altitude  on a Federal airway, jet route, RNAV low or high route,  or other direct route for which an MEA is designated at  which adequate reception of navigation signals is assured.  MAAs represent procedural limits determined by technical  limitations or other factors, such as limited airspace or  frequency interference of ground-based facilities.  The MOCA is the lowest published altitude in effect between  2-36  Minimum Obstruction Clearance Altitude  (MOCA)  Figure 2-58. Minimum obstacle clearance altitude (MOCA).  Minimum obstacle clearance altitude  Figure 2-57. Maximum authorized altitude (MAA). 