text: Chapter 2
  The three engineer disciplines encompass tasks along the lines of engineer support. The combat
  engineering discipline, due to its support to maneuver forces in close combat, is primarily focused on tasks
  that assure mobility and enhance protection. The general engineering and geospatial engineering disciplines
  perform tasks along all four lines of engineer support. Geospatial engineers provide standard and nonstandard
  geospatial products, mission-tailored analysis, tactical decision aids, and visualization products that enable
  the commander and staff to visualize the OE. Geospatial engineers also conduct data management of standard
  and nonstandard geospatial products and information necessary to plan and support operations.
  ASSURE MOBILITY
  The assure mobility line of engineer support orchestrates the combat, general, and geospatial
  engineering capabilities in combination to allow a commander to gain and maintain a position of advantage
  against an enemy (mobility) and deny the enemy the freedom of action to attain a position of advantage
  (countermobility). These tasks primarily focus on support to the movement and maneuver warfighting
  function, to include support to special operations forces. Although normally associated with organic combat
  engineers, general engineers may be task-organized to support this line of engineer support. This line of
  engineer support does not include engineer tasks intended to support the administrative movements of
  personnel and materiel. Such tasks are normally intended to enable logistics.
  The assure mobility line of engineer support is achieved through the assured mobility framework
  described in ATP 3-90.4. The assure mobility line also supports countermobility, which enables combined
  arms forces to operate anywhere along the range of operations. Countermobility shapes enemy movement
  and maneuver and prevents the enemy from gaining a position of advantage. In the offense, countermobility
  operations are conducted to isolate objectives and prevent the enemy from repositioning, reinforcing, and
  counterattacking. See ATP 3-90.8 for more information.
  Support to Mobility
  Engineer support to mobility includes the following primary tasks:
  * Conduct combined arms breaching.
  * Conduct clearing (areas and routes).
  * Conduct a gap crossing.
  * Construct and maintain combat roads and trails.
  * Construct and maintain forward airfields and landing zones.
  Mobility is a quality or capability of military forces which permits them to move from place to place
  while retaining the ability to fulfill their primary mission (JP 3-17). As described in FM 3-90-1, mobility is
  the key to successful operations. The primary purpose for mobility is to mitigate the effects of natural and
  man-made obstacles and to enable friendly forces to move and maneuver freely. Mobility tasks include
  bypassing, reducing, or clearing obstacles (including gaps) and marking lanes and trails to enable friendly
  forces to move and maneuver freely. These tasks frequently occur under conditions that require combat
  engineer units and most frequently occur when conducted at the tactical level in support of maneuver. Support
  to early-entry operations includes reconnaissance that would mitigate anti-access and area-denial
  mechanisms to clear and open APOD and SPOD. These tasks are often considered combat engineering tasks,
  even though general engineer units can perform them when the conditions allow.