When halting a convoy, simply stacking the vehicles up on the road one-after-the-other is not the ideal way to do things. While this can be used for very brief halts, the better choice for reaction-to-contact or longer-duration halts is either the Herringbone formation (preferred, as it's the easiest to do) or the Coil formation.
Note, of course, that infantry should conduct dismount drills and provide local security whenever convoy halts are made, as described previously.
Herringbone Formation
The standard formation to use when halting a convoy is known as the "Herringbone". In this, the vehicles pull off to both sides of the road in an alternating manner - the first vehicle pulls off to the right, second to the left, third to the right, and so on. The vehicles stay angled at about a 45° angle relative to the road. This formation is easy to execute and allows for the convoy to get good security when halted while also spreading the vehicles out a bit more than otherwise. This formation can be used in open terrain as well, in which case the direction of movement becomes the "road" and vehicles move relative to it.
The other formation that can be used is more geared towards armored vehicles. When executing a "Coil" formation, the lead vehicle stops and faces forward, the second vehicle pulls to the left and faces left (angling their strong frontal armor to the left), the third vehicle pulls to the right and faces right, while the trail vehicle turns around or spins in place so that it is oriented towards the rear. This allows for the vehicles to place their strongest armor in the direction that they're covering and provides excellent 360° security.
