text: Support Area Responsibilities
  Lines of Communications Security
  4-62. The security and protection of LOCs and supply routes are critical to military operations because most
  support traffic moves along these routes. The security of LOCs and supply routes (rail, pipeline, highway,
  and waterway) presents one of the greatest security challenges in the support area. Route security operations
  are defensive in nature and are terrain-oriented. A route security force may prevent an enemy or adversary
  force from impeding, harassing, or destroying traffic along a route or portions of a route by establishing a
  movement corridor. Organizations task-organized to the designated support area land owner (engineer,
  CBRN, military police, EOD) are capable of providing security and protection of LOC and supply routes that
  are identified as critical to military operations. Units conduct synchronized operations (mobility and
  information collection) within the movement corridor. A movement corridor may be established in a high-
  risk area to facilitate the movement of a single element or to accommodate an enduring operation. See
  appendix B for additional information on LOC.
  Checkpoints and Combat Outposts
  4-63. It is often necessary to control the freedom of movement in an AO for a specific period of time or as a
  long-term operation. This may be accomplished by placing checkpoints and combat outposts along
  designated avenues and roadways or on key terrain identified through METT-TC. Checkpoints are used for
  controlling, regulating, and verifying movement; combat outposts are used for sanctuary, support,
  information collection, or area denial. See ATP 3-90.4 for more information on combat outposts.
  Checkpoints
  4-64. Checkpoints monitor and control the movement of personnel and vehicles, inspect cargo, enforce laws
  and regulations, and provide information. They may be used simply to coordinate movement and surveillance
  activities. Establishing checkpoints is a critical measure in a commander’s overall security efforts. A
  commander designates checkpoints along a movement route to assist marching units in complying with the
  timetable. The movement overlay identifies critical points along the route where interference with movement
  might occur. Commanders position traffic control posts along the route to prevent congestion and confusion.
  They may be manned by military police or other unit personnel. These Soldiers report to the appropriate area
  movement control organization when each convoy, march column, and march serial arrives and completes
  passage of their location. Checkpoints may indicate critical terrain features, help to coordinate air-ground
  integration, and enable effective civil control.
  Combat Outpost
  4-65. A combat outpost is a reinforced observation post that is capable of conducting limited combat
  operations. While the factors of METT-TC determine the size, location, and number of combat outposts
  established by a unit, a reinforced platoon typically occupies a combat outpost. Mounted and dismounted
  forces can employ combat outposts. Combat outposts are usually located far enough in front of the protected
  force to preclude enemy ground reconnaissance elements from observing the actions of the protected force.
  Considerations for employing combat outposts—
  * Allow security forces to be employed in restrictive terrain that precludes mounted security forces
  from covering the area.
  * Can be used when smaller observation posts are in danger of being overrun by enemy forces
  infiltrating into and through the security area.
  * Enable a commander to extend the depth of their security area.
  * Should not seriously deplete the strength of the main body.
  4-66. Forces manning combat outposts can conduct aggressive patrolling, engage and destroy enemy
  reconnaissance elements, and engage the enemy main body before their extraction. The commander should
  plan to extract their forces from the combat outpost before the enemy has the opportunity to overrun them.