ADP 3-90, page 84

Chapter 5 5-4 ADP 3-90 31 July 2019 sustainment requirements. When necessary, dismounted and mounted marches can be hurried by conducting a forced march. (See FM 4-01 for a discussion of these various transportation modes.) MOVEMENT CONTROL 5-13. Movement control is the dual process of committing allocated transportation assets and regulating movements according to command priorities to synchronize distribution flow over lines of communications to sustain land forces. Commanders’ priorities guide the conduct of movement control. Movement control gives commanders the ability to deconflict troop movements with the distribution of supplies and services. RELIEF IN PLACE 5-14. A relief in place is an operation in which, by direction of higher authority, all or part of a unit is replaced in an area by the incoming unit and the responsibilities of the replaced elements for the mission and the assigned zone of operations are transferred to the incoming unit (JP 3-07.3). (Note. The Army uses an AO instead of a zone of operations.) The incoming unit continues the operation as ordered. Commanders conduct a relief in place as part of a larger operation, primarily to maintain the combat effectiveness of committed units. The higher echelon headquarters directs when and where to conduct a relief, and it establishes the appropriate control measures. The commanders participating in the relief in place communicate when the relieving commander has sufficient combat power and understanding of the AO to assume responsibility of the area. 5-15. There are three types of relief in place operations:  A sequential relief in place occurs when each element within the relieved unit is relieved in succession, from right to left or left to right, depending on how it is deployed.  A simultaneous relief in place occurs when all elements are relieved at the same time.  A staggered relief in place occurs when a commander relieves each element in a sequence determined by the tactical situation, not its geographical orientation. 5-16. Simultaneous relief in place takes the least time to execute but is easily detected by the enemy. Sequential or staggered reliefs can occur over a significant amount of time. These three relief techniques can occur regardless of the mission and operational environment in which the unit is participating. 5-17. A relief in place can be characterized as either deliberate or hasty depending on the amount of planning and preparation associated with the relief. The major differences are the depth and detail of planning and the time available. Deliberate planning allows unit commanders and staffs to identify, develop, and coordinate solutions to potential problems before they occur. (See FM 3-90-2 for additional information on the conduct of a relief in place.) PASSAGE OF LINES 5-18. A passage of lines is an operation in which a force moves forward or rearward through another force’s combat positions with the intention of moving into or out of contact with the enemy (JP 3-18). A passage of lines may be designated as a forward or rearward passage of lines. A passage of lines occurs under two conditions:  A forward passage of lines occurs when a unit passes through another unit’s positions while moving toward the enemy.  A rearward passage of lines occurs when a unit passes through another unit’s positions while moving away from the enemy. Ideally, a passage of lines does not interfere with conducting the stationary unit’s operations. (See FM 3-90-2 for additional information on passage of lines.) 5-19. A commander conducts a passage of lines to continue an attack or conduct a counterattack, retrograde, or security operation when one unit cannot bypass another unit’s position. The conduct of a passage of lines potentially involves close combat. It involves transferring the responsibility for an AO between two commanders. That transfer of authority usually occurs when roughly two-thirds of the passing force has moved through the passage point. If not directed by higher authority, the two unit commanders determine—