Anti-vehicle barrier

An Anti-Vehicle Barrier is a wall of plasma energy used to stop vehicles and weapons. The Covenant barrier can be easily penetrated by other objects, including enemy infantry.

Background
The barrier functions similarly to a large shield door, and bears a resemblance to the Deployable Cover equipment. It was first seen in use on Harvest, and it was later used during the Battle of Mombasa and on the Tsavo Highway to prevent UNSC forces from reaching Voi.

Trivia

 * It is only effective in halting vehicles and projectiles; a soldier on foot can traverse it harmlessly.
 * It can be taken down by explosions near the shield generator on the side opposite the generator.
 * In Halo 3, the shield barrier can sometimes be destroyed from the outside by explosives. The shield is not scripted to block the splash damage of explosives, therefore the generator is vulnerable. This can be especially helpful on higher difficulties, as the player can destroy the shield from a distance without having to engage multiple Brutes in close quarters. It may also be destroyed by ramming the generation point hard enough with a vehicle; it is possible that minor splash damage occurs upon the crash, thus destroying the barrier.
 * Another variant of the Anti-Vehicle Barrier appears in Halo 3: ODST, used by the Covenant to close down areas in New Mombasa. These shields do not allow vehicles nor infantry to pass through, and the generator that projects the shield is also fully protected by it.