Section 7: VEHICLE BARRIER DESIGN AND INSTALLATION
Vehicle Barrier Types. Vehicle barriers are categorized as either active or passive.
Active and passive barriers can be fixed or movable, depending on how they are made, operated, or
used. Some commercial barriers are dual classified, when they meet the requirements for both
categories (e.g., fixed-active, portable-passive, etc.) There is no industry-wide standard terminology
for vehicle barriers. For this handbook, the following definitions will be used.
Active Barrier Systems. An active barrier requires some action, either by personnel,
equipment, or both, to permit entry of a vehicle. Active barrier systems include barricades, bollards,
beams, gates, and active tire shredders.
Passive Barrier Systems. A passive barrier has no moving parts. Passive barrier
effectiveness relies on its ability to absorb energy and transmit the energy to its foundation.
Highway medians (Jersey bounce), bollards or posts, tires, guardrails, ditches, and reinforced fences
are examples of passive barriers.
Fixed Barrier Systems. A fixed barrier is permanently installed or requires heavy
equipment to move or dismantle. Examples include hydraulically operated rotation or retracting
systems, pits, and concrete or steel barriers. Fixed barrier systems can be either active or passive.
Portable/Movable Barrier Systems. A portable/movable barrier system can be relocated
from place to place. It may require heavy equipment to assist in the transfer. Hydraulically
operated, sled-type, barricade systems, highway medians, or filled 55-gallon drums that are not set
in foundations are typical examples. Portable/movable barrier systems can be either active or
Design Considerations. In addition to calculating the kinetic energy of a threat vehicle
(Section 6), there are other issues that must be considered before selecting an appropriate barrier
system. These issues are discussed below.
Fencing. Fences should not be considered as protection against a moving vehicle attack.
Most fences can be easily penetrated by a moving vehicle and will resist impact only if
reinforcement is added. Fences are primarily used to:
a) Provide a legal boundary by defining the outermost limit of a facility;
b) Assist in controlling and screening authorized vehicle entries into a secured
area by deterring overt entry elsewhere along the boundary;
c) Support detection, assessment, and other security functions by providing a
"clear zone" for installing lighting, intrusion detection equipment and CCTV;