25 May 2005
potential attacker from opening the final denial barrier if the security personnel are
incapacitated during an attack. The emergency deactivation key should be kept by the
duty officer or in a central location and should be different than the key required for
normal operation of the master control panel. Controls located in the overwatch position
should be capable of being secured when the position is not manned.
Most active barrier systems are capable of being operated through several devices such
as push button switches, wired and wireless hand operated switches, computer control
systems, and radar or detection loop monitoring excessive speed or unauthorized entry.
Due to the dangers associated with activation of a barrier system and the potential for
false alarms, in no case should activation of the barrier system be triggered through
automatic detection and response. All control systems should be based on the actions
of the security personnel manning the entry control facility (such as push button or hand
operated switches). This will provide an opportunity for security personnel to distinguish
confused, inattentive, or drunk drivers from potential terrorists attempting forced entry
(Securing U.S. Army Site Access Points.)
Automatic detection equipment such as detection loops or radar for excessive speed or
wrong direction of travel could be utilized for warning security personnel of potential
threats. Final selection of control systems should follow the guidance in UFC 4-022-02
and the preferences of the user.
Limitations on the maximum speed serve to reduce the potential for fatalities. For this
reason, the speed of traffic in the ECF should be kept to the minimum necessary to
maintain the flow of traffic.
VEHICLE INSPECTION CAPABILITY
Vehicles are inspected in accordance with local directives, from random inspections to
inspections of all vehicles entering the installation. Once vehicles have been inspected,
they do not have to pass through the ID check station; the exit lane from the inspection
area may bypass entry control and merge into other inbound traffic downstream. Active
barriers and procedures should be in place to prevent unauthorized vehicles from
bypassing entry control.
Location of Inspection Area
Since vehicle content inspection can be time consuming, during periods of random
vehicle content inspection it is important to allow the inspection to occur without
impeding the flow of traffic through the entry control facility. One study showed that
random in-lane inspections of approximately 1 in 30 vehicles consumed 27 minutes per
lane per hour based on a typical inspection time of 2 to 3 minutes per vehicle. If the
inspections were removed from the roadway, the installation could process vehicles for
the full hour, rather than 33 minutes. This would represent a 182 percent increase in
the available processing time and increase the processing rate from 321 vehicles per
hour per lane to 584 vehicles per hour per lane (Traffic Engineering and Highway Safety
Bulletin: Gates Revisited.)