text: Security Operations
  tactical road march, an approach march, or tactical movements parallel to the main body and drops off
  observation posts or occupies battle positions along the flank of the main body. This technique keeps the two
  forces from interfering with each other during deployment. When another force penetrates the line of contact,
  and the main body is not in contact with the enemy and is moving quickly, it is appropriate that the LD is
  uncontested. The IPB process indicates that enemy contact is not likely in the area through which the security
  force is moving. It is the fastest but least secure technique.
  Figure 5-9. Security force crossing the LD separately to establish a flank screen