Research Brief
Homeland Security
A R A N D I N F R A S T R U C T U R E , S A F E T Y, A N D E N V I R O N M E N T P R O G R A M
A Framework for Planning Cost-Effective Rail Security
Against a Terrorist Attack
RAND RESEARCH AREAS
THE ARTS
CHILD POLICY
CIVIL JUSTICE
EDUCATION
ENERGY AND ENVIRONMENT
HEALTH AND HEALTH CARE
INTERNATIONAL AFFAIRS
NATIONAL SECURITY
POPULATION AND AGING
PUBLIC SAFETY
SCIENCE AND TECHNOLOGY
SUBSTANCE ABUSE
TERRORISM AND
HOMELAND SECURITY
TRANSPORTATION AND
INFRASTRUCTURE
WORKFORCE AND WORKPLACE
E
ach weekday, more than 12 million passengers take to U.S. railways. While there
have been no successful attacks on U.S. rail
systems recently, attacks on passenger-rail
systems around the world—such as the London
Underground in 2005—highlight the vulnerability of rail travel and the importance of rail
security for passengers.
RAND researchers have developed a framework
for security planners and policymakers to guide
cost-effective rail-security planning, specifically
for the risk of terrorism, and demonstrated its use
on a notional intracity rail system that characterizes
rail systems typically found in the United States.
From Where Is the Threat Likely to Come?
This product is part of the
RAND Corporation research
brief series. RAND research
briefs present policy-oriented
summaries of published,
peer-reviewed documents.
Corporate Headquarters
1776 Main Street
P.O. Box 2138
Santa Monica, California
90407-2138
TEL 310.393.0411
FAX 310.393.4818
© RAND 2007
www.rand.org
Drawing primarily on available data on past
terrorist attacks on rail systems from the RANDMIPT Terrorist Incident Database, the study
found that bombings are the most prevalent
terrorist threat to rail systems; that most such
attacks produce few fatalities and injuries; and
that attacks in densely packed rail cars and
interior rail-facility locations are of particular
concern because of the casualties they can produce. Not all such attacks come from explosives,
so security measures must address both explosive
devices and the possibility of rarer attack modes.
Also, given the damage from a relatively small
number of large attacks, security measures that
prevent only the largest-scale attacks could significantly reduce the associated human costs.
How and Where Is a Rail System Most
at Risk?
To understand how to protect rail systems, we
examined 11 potential attack locations in a rail
system and then subjected them to eight potential attack modes. Each of the resulting scenarios
was then categorized as high, medium, low, or
no risk. (The latter occurs when the target-attack
Abstract
U.S. communities depend on reliable, safe,
and secure rail systems, but such systems
are vulnerable to terrorist attack. This brief
explains a framework for security planners
and policymakers to guide cost-effective railsecurity planning and applies it to a notional
rail system that characterizes rail systems
typically found in the United States. While the
analysis results are specific to the notional system, the framework itself is useful for planning
rail-security options.
combination is not possible.) The figure shows
the results of that qualitative filtering.
We note that some rail-attack modes are
more of a concern than others. For example, the
use of small explosives is a high or medium risk
for most targets, while hoaxes or threats pose a
risk for only a few targets. Second, some targets
are more of a concern than others. For example,
the target of system-operation and power infrastructure is a high or medium risk for seven of
the eight attack modes. Then again, underground
infrastructure is less of a target when assessed
against the attack modes.
How Can We Think About Protecting a
Notional Rail System?
In thinking about how to defend rail systems,
we started with a relatively simple, notional rail
network located within a major metropolitan
area, consisting of five spokes of unique rail lines
going directly into one hub station, with the
only transfer point between these lines located at
the hub station. We assumed that the notional
rail-security system would have some security
measures in place. Finally, we adopted a Federal
Transit Administration vision of a multilayered
Elevated
station
Ground-level
station
Ground level
System-operation
and power
infrastructure
Below-ground
station
Weapon placed
inside train
Underground
vehicle
stations
Station
access and
pathways
Large
explosive
Small
explosive
Underground
infrastructure
External,
underground
Ground-level
attack on
the train
stations
High
High
High
Large
incendiary
High
Medium
High
Medium
External,
ground-level
or elevated
Ground-level
attack on
infrastructure
train
Elevated
infrastructure
Elevated
station
Systemoperation
and power
infrastructure
High
High
High
High
High
High
High
Low
High
Medium
High
High
High
Low
High
Low
Medium
Medium
Small
incendiary
High
High
Low
Low
Medium
Low
Medium
Medium
Armed attack
High
High
High
Medium
High
High
High
Medium
Unconventional
weapon
High
High
Medium
Medium
Low
Sabotage
Hoax or threat
Medium
Low
Medium
High
Low
High
High
Low
High
High
High
Low
transportation-security system, in which we defined security
layers going from safeguarding the outermost perimeter to
the exterior, interior, and restricted-access areas to the innermost rail-security asset, the trains.
Having defined the notional system’s existing security, we
identified 17 security-improvement options and assessed their
relative effectiveness across the security layers. We evaluated
effectiveness by assessing how well the options prevented or
reduced the probability of a specific terrorist attack occurring,
reduced or averted the number of passenger fatalities in the
system, reduced the time necessary for system facilities and
infrastructure to be restored and operations fully resumed, and
minimized rail-operating revenue losses. We rated options in
terms of both their incremental impact at each layer and their
potential system-level contribution across layers.
At the system level (integrating across layers), we identified four broad categories of cost-effective security measures
for system operators to consider in terms of effectiveness for
dollar metric payoffs: (1) relatively inexpensive solutions with
the highest effectiveness (e.g., enhanced security training);
(2) additional inexpensive solutions to consider with reasonable levels of effectiveness (e.g., installing retractable bollards at
entrances and exits of the operation-control center and power
plant); (3) costlier solutions with highest effectiveness (e.g.,
installing fixed barriers at curbsides adjacent to all entrances
Low
Medium
and passageways leading to ground-level and underground
stations); and (4) relatively expensive, longer-term solutions for
future consideration (e.g., rail-vehicle surveillance systems).
Conclusions
The prioritized options are specific to the notional system
analyzed, and the analysis captures a point in time, such that
the current costs for those options and their current perceived
effectiveness drive the attractiveness of different options.
Thus, even if the preferred options are viewed as reasonable
for a given system, even that conclusion is perishable.
These limitations notwithstanding, the framework itself is
useful for planning rail-security options but should be tested
against other systems of varying complexity. Such testing will
yield two insights. First, it will help us better understand whether
the portfolio of preferred options varies with system complexity
or is largely the same regardless. Since risk and the nature of
preexisting measures vary by the type of system examined, such
testing will also give some insight into the dynamic nature of the
threat and security assessment process and, perhaps, the timeline
over which the assessments need to be repeated to counter the
fact that terrorists wield new methods and learn their potential
targets’ defenses over time. Second, applying the framework to
systems of differing complexity will allow us to better understand
the information demands that the framework imposes. ■
This research brief describes work done for RAND Infrastructure, Safety, and Environment documented in Securing America’s
Passenger-Rail Systems, by Jeremy M. Wilson, Brian A. Jackson, Mel Eisman, Paul Steinberg, and K. Jack Riley, MG-705-NIJ (available
at http://www.rand.org/pubs/monographs/MG705/), 2007, 142 pp., $28, ISBN: 978-0-8330-4117-3. The RAND Corporation is a
nonprofit research organization providing objective analysis and effective solutions that address the challenges facing the public and
private sectors around the world. RAND’s publications do not necessarily reflect the opinions of its research clients and sponsors.
R® is a registered trademark.
RAND Offices
Santa Monica, CA
•
Washington, DC
•
Pittsburgh, PA
•
Jackson, MS / New Orleans, LA
•
Cambridge, UK
•
Doha, QA
RB-9309-NIJ (2007)
THE ARTS
CHILD POLICY
This PDF document was made available from www.rand.org as a public
service of the RAND Corporation.
CIVIL JUSTICE
EDUCATION
ENERGY AND ENVIRONMENT
HEALTH AND HEALTH CARE
INTERNATIONAL AFFAIRS
NATIONAL SECURITY
This product is part of the RAND Corporation
research brief series. RAND research briefs present
policy-oriented summaries of individual published, peerreviewed documents or of a body of published work.
POPULATION AND AGING
PUBLIC SAFETY
SCIENCE AND TECHNOLOGY
SUBSTANCE ABUSE
TERRORISM AND
HOMELAND SECURITY
TRANSPORTATION AND
INFRASTRUCTURE
The RAND Corporation is a nonprofit research
organization providing objective analysis and effective
solutions that address the challenges facing the public
and private sectors around the world.
WORKFORCE AND WORKPLACE
Support RAND
Browse Books & Publications
Make a charitable contribution
For More Information
Visit RAND at www.rand.org
Explore the RAND Homeland Security Program
View document details
Limited Electronic Distribution Rights
This document and trademark(s) contained herein are protected by law as indicated in a notice appearing later
in this work. This electronic representation of RAND intellectual property is provided for non-commercial
use only. Unauthorized posting of RAND PDFs to a non-RAND Web site is prohibited. RAND PDFs are
protected under copyright law. Permission is required from RAND to reproduce, or reuse in another form,
any of our research documents for commercial use. For information on reprint and linking permissions, please
see RAND Permissions.