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 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.
 * How this barrier works is uncertain. If it blocks a certain kind of metal, it should also block Spartans and Marines who also wear plate armor.
 * On Halo 3, the shield barrier can sometimes be destroyed from the outside