Chapter 12 – Freeway Management
During Emergencies and Evacuations
Page 2 of 2
12.3.3 Public Outreach
Positive public response to evacuation warnings is essential for the
successful, safe, and efficient evacuation of an area. Prior to hurricane
season, public awareness campaigns remind the public to prepare for hurricanes.
As a hurricane approaches, the appropriate notification procedures and
messages must be used to convince the public that evacuation is in their
best interest. Several effective methods to promote public awareness include:
- Educational campaigns;
- Public service announcements;
- Brochures illustrating designated evacuation routes;
With respect to the Internet, several states publish their Hurricane
Evacuation Routes on their DOT and other agency web sites (Figure 12-1),
along with additional disaster-related information and links (e.g.,
evacuation decision-making criteria, preparedness information and checklists,
real-time weather and traffic conditions, shelter sites and hotels, home
and business protection).
12.3.4 Area of Impact / Analyses
Hurricane evacuation studies (HES) were initiated in the 1980's by the
Federal Emergency Management Agency (FEMA) to integrate key aspects of
hurricane evacuation planning and to assist in disaster preparedness.
A HES typically consists of the analyses noted below (13);
and though it is focused on hurricanes, the general principles are applicable
to all emergency evacuations:
- Hazards Analysis: The primary objective of the hazards
analysis is to determine the probable worst-case effects from the various
intensities of hurricanes that could strike the region. The study identifies
"worst-case effects" (i.e., the peak storm surges, high wind
speeds, inland flooding, and wave effects) that can be expected at all
locations within the study area, regardless of the point of hurricane
- Vulnerability Analysis: The purpose of the vulnerability
analysis is to identify the areas, populations, and facilities that
are potentially vulnerable to flooding and extraordinary wind damage
under a variety of hurricane threats. The vulnerable population is comprised
of all persons residing within the area subject to storm surge and the
residents of mobile homes located above expected flood levels.
- Behavioral Analysis: In preparing hurricane evacuation
plans, assumptions must be made regarding the manner in which the population
in and around the vulnerable area will react to the threat, including
the percentage that will evacuate, the probable destinations, the number
of vehicles that will be used (including the number that may be motor
homes or towing boats / campers), the evacuation response of tourists,
and the percentage of evacuees who would require public assistance for
emergency transportation. These assumptions are necessary for shelter
planning, transportation modeling, and guidance in evacuation decision-making
and public awareness efforts.
- Shelter Analysis: The purposes of the shelter analysis
are to estimate the number of evacuees that will seek public shelter
and the number of shelter spaces available, and to provide information
for use in determining evacuation clearance times in the transportation
- Transportation Analysis: The primary purpose of
the transportation analysis is to calculate the clearance times needed
to conduct a safe and timely evacuation for a range of hurricane threats.
Other purposes are to define the evacuation roadway network and to evaluate
traffic control measures/highway improvements for improved traffic flow.
Some of the considerations and issues are noted below:
- In choosing roadways for the hurricane evacuation network, care
should be taken to designate only those roads that are not expected
to flood from rainfall or storm surge while the evacuation is in
progress. Other desirable characteristics are little or no adjacent
tree coverage, substantial shoulder width and surface, and current
designation as an evacuation route in an existing evacuation plan.
- Clearance times – which vary depending upon storm scenario, behavioral
response, and (if appropriate) tourist occupancy level – are an
important product of the analysis. Clearance time is normally estimated
for each county. It begins when the first evacuating vehicle enters
the roadway network, prior to an evacuation order or advisory, ends
when the last vehicle reaches an assumed point of safety, and includes
the time spent traveling along the roadway network and waiting due
to traffic congestion (queuing delay time).
- The movement of evacuating vehicles during a hurricane evacuation
requires extensive traffic control efforts to make maximum use of
roadway capacity and to expedite safe escape from hurricane hazards.
The transportation analysis should reveal critical roadway segments
and intersections and recommend specific traffic control measures
and/or roadway modifications to help alleviate the anticipated problems
in these areas.
184.108.40.206 Transportation Modeling Methodology
One of the means of planning and preparing for evacuations involves the
use of computer modeling. The traffic models noted in Chapter 4 (e.g.,
CORSIM, INTEGRATION, PARAMICS, VISSIM, TRANSIMS, DYNASMART) can be used
for a variety of emergency / evacuation / reentry scenarios by changing
the appropriate network and traffic flow parameters. Additionally, specialty
models for emergency management have been developed as summarized below:
- The most widely applied flooding model for evacuation analysis is
the Sea, Lake and Overland Surges from Hurricanes (SLOSH) model. Developed
by the National Weather Service to predict hurricane storm surge for
a given set of conditions, it is also used to plan evacuation routes
and locate emergency shelters based on estimates of which geographic
could be flooded in certain storm scenarios. SLOSH is used by weather
experts at NOAA.
- Hurricane and Evacuation (HURREVAC) program. HURREVAC is a decision
support system for emergency management officials. It uses geographic
information system (GIS) information to correlate demographic data with
shelter locations and their proximity to evacuation routes to estimate
the effect of strategic-level evacuation decisions. (Note: Additional
information on HURREVAC can be found at http://hurricanes.noaa.gov/prepare/hurrevac.htm)
- The Oak Ridge Evacuation Modeling System (OREMS) – developed by the
Center for Transportation Analysis at the Oak Ridge National Laboratory
(ORNL) using the CORridor SIMulation (CORSIM) platform – OREMS was developed
to simulate traffic flow during various defense-oriented emergency evacuations.
The model can be used to estimate clearance times, identify operational
traffic characteristics, and other information such as evacuation routes
and times necessary to develop evacuation plans. It also allows users
to experiment with alternate routes, destinations, traffic control and
management strategies, and evacuees' response rates.
- The Evacuation Traffic Information System (ETIS) is a secure, web-based,
Geographic Information Systems tool developed to assist the Evacuation
Liaison Team, state emergency managers, and state traffic engineers.
It enables them to share information with each other, and to provide
information on the anticipated traffic levels and patterns. (At this
time, it is only available to officials within the hurricane community.)
The main page of the ETIS displays a map of the U.S. from Texas to Maryland,
and shows information on counties that have called an evacuation, the
evacuation participation rate and type (i.e., voluntary or mandatory
evacuation), expected congestion levels on primary evacuation routes,
and road closures. Tables accessible through the system give the anticipated
state-to-state traffic volumes and likely destinations of the evacuees.
12.3.5 Traffic Management Plans
220.127.116.11 Contraflow Lanes
Contraflow, or reverse laning as it is also commonly known, involves
the reversal of traffic flow in one or more of the inbound lanes (or shoulders)
for use in the outbound direction with the goal of increasing capacity.
Four different variants of contraflow may be used as shown schematically
in Figure 12-2. Because it offers the largest increase in capacity, the
most common contraflow strategy is to reverse all inbound lanes to the
Figure 12-2: Contraflow Operational Scenarios (Reference
Though not as widely used, single-lane contraflow strategies are also
possible, such as one lane reversed and one lane with inbound flow for
emergency/service vehicle entry only; and one lane reversed and one lane
with normal flow for inbound traffic entry. The main advantage of this
strategy is its ability to maintain a lane for inbound law enforcement
personnel and emergency service vehicles, critical for clearing incidents.
It can also permit access for people that want to move against the evacuation
traffic. One of the major drawbacks of single-lane reversals is that it
raises the potential for head-on accidents.
Another strategy to improve capacity is to use the outbound left shoulder
as an additional outbound lane. The capacity increase depends on the width
and condition of the shoulder. Two additional concerns associated with
the use of shoulders are pavement suitability and bridge widths. Shoulders
are typically designed with a thinner pavement cross-section and greater
cross-slope. They may not be able to withstand prolonged traffic loading
and thus provide an inadequate riding surface. Cross-section width can
be a problem on bridges. Many freeway bridges, particularly older ones,
have been constructed with narrow shoulders. If shoulders were used as
outbound lanes, these locations would create bottlenecks causing additional
congestion as vehicles merge back into the through lanes.
Contraflow sections typically start with a median crossover or traffic
control configuration that redirects or splits a portion of the outbound
traffic stream into the inbound lanes. The specific location of these
crossover points is usually a function of roadway geometry, the approximate
beginning of congestion during evacuations, and the proximity of the location
to other evacuation routes.
Contraflow section termini designs also vary by location. One of the
controlling criteria for the location of a termination point is the prevention
of merging congestion. This can be accomplished in several different ways:
- The method that is most common, particularly for shorter segments,
is to permanently split the traffic flows. In this type of design one
of the streams of traffic is diverted onto a separate roadway, while
the other continues travel on the original route.
- The other common type of contraflow termini design is the attrition-merge.
In this design, traffic in the normal and reverse flow lanes is reduced
by allowing vehicles to exit to secondary routes at points along the
contraflow segment. Through a process of exit attrition, it is assumed
that traffic would be reduced to a level at the end of the segment that
would allow a merging of the traffic streams without causing bottleneck
Cross-over designs should also address the placement and location of
traffic control devices in the vicinity of the crossover, the use of highway
advisory radio (HAR) and dynamic message signs (DMS) to guide evacuees,
and the specific numbers and locations of police vehicles at the beginning
and termination points and along the ramps of the segment. Another possibility
is the installation of drop-gate barricades at the upstream end of on-ramps
to assist in the control and diversion of in-bound traffic flow
Other management and operational issues associated with contraflow lanes
for evacuations include:
- Use of contraflow for reentry of evacuated individuals following
- Time and labor required to set up, initiate, and enforce contraflow
operations (e.g., traffic control devices and barricades must be erected
and weighted down, inbound lanes must be cleared of vehicles over their
length, and law enforcement and DOT field personnel must be positioned
at their assigned locations). Set up time depends on the length of the
segment, the number of interchanges involved, and the number ramps and
merge points that may require control.
- Criteria affecting decisions as to if and when to initiate contraflow
operations (e.g., storm characteristics (size, intensity, track) and
potential risks; traffic volume; set up time; and time of day)
- Factors for determining when to shutdown the evacuation (e.g., the
arrival of tropical storm force winds, and the need to evacuate DOT
and enforcement personnel; decrease in evacuation traffic volumes; time-of-day /nightfall).
- Who has the authority to start and end contraflow operations (refer
to discussions in Chapter 2). In most states, this authority resides
with the Governor, although that responsibility falls on enforcement
and/or transportation officials in a few states.
As an example of the effectiveness and benefits of contraflow operations,
Reference 14 "Best Practices for Road Weather Management,
Version 2.0" provides the following excerpt. From a cases study entitled
"South Carolina Hurricane Evacuation Operations". "On Tuesday, September
14th the Governor issued a voluntary evacuation order at 7:00 AM followed
by a mandatory evacuation order at noon. In response, over 350,000 people
evacuated on Tuesday, and roughly 160,000 departed on Wednesday. The timing
of evacuation orders, the public's response to the orders, the lack of
lane reversal operations, and unmanned traffic signals in small towns
contributed to severe congestion on Interstate 26 between Charleston and
Columbia. Travel time, which is normally 2½ hours, ranged from
14 to 18 hours during the evacuation. The maximum per lane volume on the
interstate was 1,445 vehicles per hour. The Governor ordered contraflow operations to minimize travel times during
reentry. Traffic and emergency managers quickly developed a contraflow
plan to accommodate reentry traffic in reversed westbound lanes. DMS and
HAR were deployed to notify travelers of closures and alternate routes.
As a result of contraflow, the maximum volume during reentry was 2,082
vehicles per hour per lane—a 44 percent increase over evacuation
volumes. Contraflow operations and dissemination of traveler information
significantly improved mobility by increasing roadway capacity and traffic
18.104.22.168 High Occupancy Vehicle Lane Usage
During an evacuation, officials may opt to allow high occupancy vehicle
(HOV) lanes to be opened to all traffic regardless of occupancy restrictions
Several issues need to be examined when considering this option. Bottlenecks
may form at the terminus of the HOV lane – particularly if the lane merges
into the general purpose lane (forcing a merge) as compared to removing
the restriction from the lane – which may reduce capacity and offset any
potential benefits. Confusion may result because not all motorists may
be familiar with HOV facilities. Public awareness prior to evacuation
is needed to ease confusion. Furthermore, dropping occupancy limitations
sets precedents for similar actions in the future and this may not be
An alternative to lifting occupancy requirements on HOV lanes would be
to encourage normal HOV lane usage during evacuations. This might encourage
people to travel in groups. Furthermore, "evacuation buses" could be provided
to get people to leave their personal vehicles behind, reducing demand
on the evacuation route. The ability of such buses to use the HOV lanes
to bypass evacuation congestion might provide strong incentives for their
22.214.171.124 Work Zones
Since the need for maintenance and construction during the hurricane
season is unavoidable, some DOTs have made attempts to avoid conflicts
by adding special provisions in construction contracts to accommodate
evacuation traffic through work zones. The most common way to do this
has been to add clauses that require a contractor to cease all construction
activities once an evacuation is declared, clear all equipment, and open
all lanes of traffic including those under construction. Other options
to maintain capacity through work zones on evacuation routes have included
limiting the construction season, distance, performance time, and/or phase
sequencing of projects. These types of contraction provisions can potentially
increase the cost and/or duration of projects, since they may require
a contractor to work in shorter segments or use non-standard construction
126.96.36.199 Traveler Information
During emergency situations (e.g., major evacuations, response and recovery
operations, national security emergencies), traffic and traveler information
requirements reach a critical point. In addition to providing information
on the locations of evacuation routes, roadway configurations (e.g., use
of shoulders, contra-flow, available exits and entrances), traffic flow
conditions / congestion on available routes, etc.; the traveler information
should also include real time information on locations and availability
of lodging and shelter, and services such as gas stations, rest area locations,
and restaurants and food stores.
188.8.131.52 Contingencies for Continued Operations
Another element of any traffic management plan is contingencies for the
continued operation of freeway management systems and regional information
sharing networks; such as redundant / emergency communications (e.g.,
satellite telephones); power, continuity of operations and essential functions
in the event that the TMC becomes inoperable. Of course, the most desirable
scenario is to locate and design the TMC such that it can continue to
operate during severe weather conditions and other emergencies (e.g.,
back up power, overnight accommodations for staff, located outside a flood
plain, seismically isolated). As this may not always be the case, it is
important to develop a "Continuity of Operations Plan" (COOP).
Presidential Decision Directive 67 requires that all Federal Departments
and agencies have a viable Continuity of Operations Plan (COOP) capability,
which details how their essential functions will be performed during an
emergency or any situation that may disrupt normal operations and leave
office facilities damaged or inaccessible. Objectives of a COOP include:
- Ensuring the continuous performance of an agency's essential functions
/ operations during an emergency
- Protecting essential facilities, equipment, records, and other assets
- Reducing or mitigating disruptions to operations
- Reducing the loss of life, minimizing damage and losses
- Achieving a timely and orderly recovery from an emergency and resumption
of full service to customers
Elements of a viable COOP include:
- Plans and Procedures, such as procedures for employee advisories,
alerts, and COOP activations
- Identification of Essential Functions. This includes determining
which functions must be continued under all circumstances, prioritizing
those functions, and identifying the associated staffing and resource
requirements (including mission critical data and systems)
- Delegations of Authority. Identify authorities for making policy determinations
and decisions during emergencies – both within the various levels of
the agency, and as participants of interagency emergency response teams,
identify the circumstances under which these delegated authorities are
exercised (become effective and terminate), identify the authority of
- Orders of Succession for key positions and titles within the agency,
including the conditions under which succession will take place and
method of notification. It is recommended that successors be geographically
dispersed, and that they receive appropriate orientation.
- Alternate Facilities – Identify alternate operating facilities, and
prepare personnel for the possibility of sudden relocation of essential
functions and / or contingency staff to these facilities. Such alternate
facilities should be capable of supporting critical operations in a
- Interoperable Communications – In order for agency operations to be
successful at an alternative facility, critical communication systems
must be available with a degree of redundancy. These communications
systems must support connectivity to internal organizations and systems,
and to other organizations and the public.
- Vital Records and Databases – Plans must also provide for the identification,
protections, and ready availability of electronic and hardcopy documents,
references, record, and information systems needed to support essential
functions under any type of emergency.
- Tests, Training and Exercises
12.3.6 Training / Exercises
A regional emergency / evacuation exercise sufficient in scope to test
all major elements of the emergency and evacuation plans should be conducted
periodically. The participants should include state, regional, and local
agencies that have emergency preparedness responsibilities. The scope
could range from only tabletop communications to full activation of field
personnel and emergency operations centers. Regardless of the scale, the
goal of the exercise should be to test the effectiveness of each emergency
management plan, including safe, efficient, and effective evacuations.
The exercise should test the ability of emergency management officials
to identify the appropriate emergency scenario as it develops, including
those of neighboring communities. Official's responses should be tested
in the areas of emergency decision making, communications, public warnings,
manpower/equipment deployment, resource allocation, timing of evacuation
order or advisory, shelter activation, emergency transportation, damage
assessment and traffic control. Communications and emergency power systems
should be fully tested, long-term if possible. Monitors should be stationed
at each emergency operations center and, if appropriate, in the field
to evaluate response activity.
A post-exercise review should be conducted to evaluate the effectiveness
of each plan. Officials who participated in the exercise should also contribute
to the review. Monitors should be asked to critique the activity to which
they were assigned. A critique report should be published that documents
the exercise methodology, identifies problem areas, and recommends improvements.
Areas where future preparedness training would be beneficial should also
12.3.7 Military Deployment Coordination
Military deployment strategy has transformed from the Cold War forward-deployed force to a capabilities-based power projection force located
largely in the United States. Strategic and mobility readiness are the
keys to the military's ability to project power. Smaller forces may be
deployed by air, while larger forces would typically be deployed by sea.
Movements by sea require that a large number of vehicles and equipment
be moved from military installations to the point of embarkation by either
railroad or by convoys on public roads. These convoys need to arrive at
a particular location at a specified time. The mission, threat, number
of troops, terrain, highway network, and time available set the specific
planning factors and influence how the convoy will be operated and managed.
During the past several years, FHWA has been working closely with the
Military Traffic Management Command Transportation Engineering Agency
(MTMCTEA) in an initiative to support military mobilization. The principal
objective of this initiative is to ensure that states have adequate coordination
procedures to support military deployments while, at the same time, managing
civilian traffic during national emergencies – in essence, to meet military
deployment needs such that these movements do not become a major impediment.
During a national security emergency involving a military deployment,
state DOT's must coordinate with both the FHWA and military transportation
organizations. Supporting roles might include:
- Issuing the correct permits (e.g., overweight, oversize vehicles)
for convoy vehicles using the State roadway system. (Note – DOD policy
states that no vehicle movement that exceeds legal limitations or regulations,
or that subjects highway users to unusual hazards, will be made without
permission from the State, local, and / or toll authority.)
- Providing operational information to the military about work zone
restrictions / closures, incidents, conditions at public rest areas
/ refueling locations, etc., that may impact convoy timeliness.
- Assessing and monitoring traffic flow conditions and operations on
the designated routes.
State and local deployment planning require an understanding of coordination
and communication protocols. It is important to know who will be calling
from the military, and whom the state agency would contact within the
military establishment to coordinate a response. A guide is being developed, with a final version expected in 2004.
12.3.8 Terrorism and Homeland Security
As discussed in previous sections, freeway management strategies and
supporting ITS technologies are clearly applicable to emergencies and
evacuation. The events of September 11, 2001 raised the consciousness
of the transportation community along with the consciousness of others,
about the need for better critical infrastructure protection and crisis
management, disaster planning and prevention, as well as effective detection
and response, particularly in the case of deliberate terrorist attacks.
Freeway management operations and the supporting ITS technologies have
an important role to play in advancing the surface transportation aspects
of Homeland Security. As an example of this new concern, ITS America in
their supplement to their 10-Year Vision (4)
added a "Security" goal, joining the goals of safety, efficiency / economy,
mobility / access, and energy / environment.
Weapons of mass destruction in the hands of terrorists introduce new
considerations to "emergency management" and disaster planning such as
- People are the intended target.
- Advance warnings are unlikely.
- Multiple simultaneous attacks are possible.
- Emergency responders may be targets.
- The weapons may introduce serious and long-lasting hazards.
- The weapons may introduce large-scale damage or contamination to
critical equipment and facilities.
- Public reaction is unpredictable.
The introduction of WMD also signals the need for some modifications
to the existing set of agency roles and responsibilities (5):
- Law enforcement and national security agencies will play a larger
role in a terrorist incident. State DOT personnel will need to understand
the different relationships inherent during and after a terrorist WMD
- If an incident occurs on or near a highway, state DOT personnel may
be first or early responders. Therefore, basic training may be needed
in identifying possible signs and consequences of terrorist incidents
for appropriate actions including the consideration of their own safety.
- Specific traffic control regimes may be needed to evacuate people
or to establish emergency access. Preplanning strategies, signage and
equipment may be appropriate together with capitalizing on Intelligent
Transportation Systems (ITS) and traveler information resources.
- Some resources may become unavailable for use if contaminated. Having
procedures and equipment in place for decontamination becomes more important.
Medical treatment and facilities could be overwhelmed quickly.
- Response resources may be required far beyond those originally anticipated;
especially where a WMD is used that initially leaves few distinguishing
marks. State DOT response resources need to be available but may also
need to be protected as the consequences spread.
- Addressing public concerns is critical. Panic and uncontrolled flight
are possible, and controls may need to be quickly put into effect. A
comprehensive public information strategy is necessary. Where highways
are concerned, state DOT personnel will be expected to provide information,
(e.g., through variable message signs) to motorists evacuating an area.
ITS provides tools and enhanced opportunities to help safeguard the transportation
system against a variety of threats, both natural and human caused, help
the transportation system and its operators react swiftly and responsively
in case of disruptions, and materially help agencies with primary responsibility
to respond – for example (from the perspective of an FMS), providing surveillance
of transportation facilities, including bridges and tunnels, and operations
/ management centers; and safeguarding ITS systems and data against inadvertent
or deliberate interference or misuse. The goal is a "transportation system
that is prepared for and well-protected against attacks, that responds
rapidly and effectively to natural and human-caused threats and disasters,
that supports appropriate transportation, emergency management, and public
safety agencies, that ensures the ability to move people and goods even
in times of crisis, and that can be quickly and efficiently restored to
full capability (4).
Information and communication systems are potentially vulnerable to hacking,
deliberate overloading, denial of service, and other technology-driven
interference, in addition to physical attack. The potential for this kind
of interference increases as transportation systems come to depend more
on information processing and dissemination, software, and communications.
This growing dependence on technology to manage and operate the freeway
network creates a critical need for:
- Protecting the availability, integrity, and confidentiality of data
- Reducing the vulnerability of systems and services and ensuring the
continuity of operations
- Guarding against the effects of cascading and escalating failures
in multiple interconnected systems.
Two guides have been recently developed in the aftermath of 9-11. They
can be downloaded from the website of AASHTO's security task force at
http://security.transportation.org/?siteid=65. Each is briefly discussed below.
184.108.40.206 Guide to Updating Highway Emergency Response Plans for Terrorist
This Guide (Reference 5) focuses the need for updating
emergency response plans in light of emerging terrorist threats using
weapons of mass destruction (WMD). It offers specific process guidance,
in a checklist format, as to how state DOTs can update their emergency
response plans. It also describes generic highway emergency response strategies
typically used by state DOTs that may be utilized for emergency response
to terrorist incidents.
The guide provides checklists designed to help state DOTs focus on where
modifications and updates may be required in their plans and procedures.
The checklists are divided into two broad topic areas:
- Internal arrangements: These checklists focus on the DOT's internal
organization and preparedness for a response to a terrorist incident.
This topic area focuses on modifications to the DOT's organization,
responsibilities, procedures, communications, equipment, training and
other critical areas.
- External relationships: These checklists focus on the state DOT's
role within the larger emergency management framework of a state. This
topic area focuses on issues that the state DOT may wish to take up
with the other major players in the state emergency planning process.
The Internal Arrangements and External Relationships categories are then
broken down further into relevant topics:
- Planning, training and exercising
- Roles and responsibilities
- First response
- Concept of operations
- System surveillance and management
- Agency communications
- Public information.
The checklist covers numerous pages, and even a summary is beyond the
scope of this Handbook. Nevertheless, there are a few program modification
considerations and process suggestions worth noting from the relatively
narrow perspective of freeway management and operations, as summarized
in Table 12-3.
Table 12-3: Emergency Management Considerations
for Freeway Management (Adopted from Reference 5)
- Understand the Incident Command System
- Terrorist incident scenes (including those on the highway)
are subject to crime scene management requirements
- A thorough analysis of potential highway and related transportation
facility vulnerabilities and risks relating to terrorist incidents,
identification of high risk or vulnerable terrorist targets within
the DOT, and developing appropriate plans to protect those potential
- As appropriate, build planned responses for the different levels
and types of threat.
- Properly equipping and credentialing (e.g., proper ID cards)
DOT personnel to perform their roles
- Know where the assets are (e.g., heavy equipment to move debris),
and determine how those assets can be deployed quickly
- Ensure surveillance can quickly be applied to high-profile/high-risk
structures, such as bridges, tunnels, highways, and overpasses,
using existing monitoring equipment, e.g., CCTV, where possible.
- Ensure that plans include procedures for limiting access to
security and other government agencies, e.g., close access ramps,
install concrete barriers at security installations and facilities
that house command centers.
- Develop evacuation route plans showing the freeways and arterials
to be used in the evacuation of traffic and people out of emergency
areas. Ensure that evacuation plans address termination of work
- Consider the feasibility of invoking reverse-laning to evacuate
emergency areas and review factors such as decision-making criteria
used to invoke the reverse-laning, modeling traffic impacts, staffing
and resource requirements, and the implementation timelines for
reverse-laning in each of the identified routes.
- Coordinate concurrent work zone activities so they do not all
occur at the same time for parallel routes in case of a terrorist
- Assuming there is more than one DOT operations center, determine
the relationship of the centers in terms of response, including
the ability to shift control depending on the locale of an incident.
If there is only one DOT operations center, identify ways to provide
redundant or backup services in the event a terrorist incident
affects the primary operations center
- Procedures for securing DOT centers
- Procuring additional portable ITS assets (DMS, HAR) to facilitate
management of critical facilities where permanent infrastructure
does not exist.
- Explore opportunities to bolster TMCs in preparation for emergency
response situations. (e.g., cover larger geographic areas; supplement
data with aerial camera links to the TMC; implement robust communication
links that are fail-safe; establish additional backups and redundancies,
perhaps at secondary locations, in case a primary location is
affected by damage, power outages, or other issues
- Add additional simulation capabilities so that traffic outcomes
of a terrorist incident can be modeled
- Determine how advanced traveler information systems might be
utilized to convey information to the public during and following
a terrorist incident.
220.127.116.11 Guide to Highway Vulnerability Assessment for Critical Asset
Identification and Protection
This Guide (16) was developed as a tool for State Departments of Transportation
- Assess the vulnerabilities of their physical assets such as bridges,
tunnels, roadways, and inspection and traffic operation facilities,
- Develop possible countermeasures to deter, detect, and delay the consequences
of terrorist threats to such assets;
- Estimate the capital and operating costs of such countermeasures;
- Improve security operational planning for better protection against
future acts of terrorism.
The Guide provides six steps for conducting a vulnerability assessment
of highway transportation assets. These six steps provide a straightforward
method for examining critical assets and identifying cost-effective countermeasures
to guard against terrorism. For each step, the objective is clearly stated,
the practice of that step by other state and federal agencies is referenced,
a detailed approach is described, and illustrative examples are provided.
Table 12-4 summarizes the six steps for conducting a vulnerability assessment
of highway transportation assets. These six steps represent an integrated
and iterative approach to vulnerability assessment. This approach depends
upon the formation of a dedicated, multidisciplinary team with ready access
to a range of resources – from databases to personnel – as well as a commitment
from senior State DOT officials to examine critical assets carefully and
identify cost-effective countermeasures to provide better protection against
the threats of terrorism involving the use of weapons of mass destruction
Table 12-4: Steps for Conducting a Vulnerability
Assessment of Highway Transportation Assets (Reference
Step 1 – Critical Assets Identification
- Create an all-inclusive list of critical assets (i.e., those
that enable the agency to achieve its mission, including infrastructure,
facilities, equipment, and personnel)
- Establish and assign values to the critical asset factors (e.g.,
vulnerability to attack, consequences of loss / damage, consequences
to public services and emergency response functions, consequences
to general public / economic impact)
- Prioritize the all-inclusive list of critical assets
Step 2 – Vulnerability Assessment: Identify and
evaluate critical assets in terms of their susceptibility to and
the consequences of terrorist attacks
- Characterize the threat
- Assign vulnerability factors to the critical assets (e.g.,
level of recognition / visibility, number of users / attendance,
proximity to vehicle traffic / parking access, level of protected
/ controlled security access, site specific hazards)
- Score the vulnerability factor for each asset
Step 3 – Consequence Assessment: Identify assets
which, if attacked, produce the greatest risks for undesirable outcomes
given a specific set of circumstances and conditions
- Plot critical asset criticality vs. vulnerability
- Consider consequences for those assets that have both high
criticality and high vulnerability.
Step 4 – Countermeasures
- Identify potential countermeasures with respect to deterrence,
detection, and defense (Refer to Table 12-5)
- Map countermeasures to high-priority critical assets
- Assess countermeasure effectiveness (i.e., a subjective measurement
as to how well the application reduces either the potential for
or the consequences of attacks)
Step 5 – Cost Estimation
- Create countermeasure "packages" (i.e., combinations of countermeasures
that make sense operationally and from a vulnerability reduction
- Determine acquisition and operations / maintenance costs
- Apply costs to assets
Step 6 – Security Operational Planning
- Clarify security planning scope and objectives
- Develop plan
- Initiate training and exercise activities (e.g., awareness,
Table 12-5: Potential Countermeasures
Potential Countermeasures (Reference
- Increase inspection efforts aimed at identifying potential explosive
devices as well as increased or suspicious potential criminal
- Institute full-time surveillance at the most critical assets
where alternate routes are limited or have not been identified.
- Eliminate parking under any of the most critical type bridges.
Elimination of the parking can be accomplished through the use
of concrete barriers.
- Place barriers in such a way as to eliminate ease of access
where a vehicle could be driven right up to the asset.
- Install security systems with video capability at all DOT facilities.
- Protect ventilation intakes with barriers.
- Install and protect ventilation emergency shut off systems.
- Install Mylar sheeting on inside of windows to protect employees
from flying glass in the case of an explosion.
- Place a full-time security officer in a guard shack to control
- Lock all access gates and install remote controlled gates where
- Develop and implement a department-wide security policy.
- Limit access to all buildings through the issuance of a security
badge with specific accesses identified and controlled through
- Train all DOT personnel to be more observant of their surroundings
and potentially dangerous packages, boxes, people, etc.
- Improve lighting
- Increase surveillance at tunnels by installing cameras linked
to the Traffic Operations Center (TOC).
- Add motion sensors to fences.
12.4.1 Northridge, CA Earthquake
On Monday, January 17, 1994, at 4:30 a.m., an earthquake of a magnitude
of 6.8 shook Los Angeles, California. While the actual earthquake (and
its subsequent aftershocks) lasted only about 1 minute, it damaged 114,000
residential and commercial structures spread over 2,100 square miles,
took 72 lives, and significantly impaired the Los Angeles regional transportation
system, generating a year's worth of highway work in a single event. The
Federal Emergency Management Agency (FEMA) reported the Northridge earthquake
as one of the largest and most costly federal disasters with initial cost
estimates of total damages at $25 billion.
Among the agencies cooperating in response to the Northridge destruction
was Caltrans. Caltrans led the successful reconstruction effort and made
two key decisions quickly after the earthquake: to rebuild the damaged
freeways, and to retain traveler mobility and keep traffic flowing as
smoothly as possible during the rebuilding efforts. Reference
17 is a case study of how this costly disaster became a model of incident
management. Some of the key points are summarized below.
18.104.22.168 Restoring Regional Mobility
During the first week following the Northridge earthquake, many businesses
and schools were closed, which significantly decreased the demand on the
freeway network. Many people also stayed at home that week to repair their
own earthquake damage. The first week after the earthquake, people began
to return to their jobs and traffic volumes were steadily increasing.
Early rough estimates indicated that repairs would take from 6 months
to a year. While contract incentives made it likely that the freeway repair
might be expedited, Caltrans knew that mitigation measures had to be implemented
quickly to balance capacity and demand. Two primary measures were implemented
to reduce strain on the highway network – alternate route and detours,
and freeway demand reduction measures. For example:
- The use of local streets proved to be the most effective way to handle
freeway detours. The damaged freeway segments were far enough apart
that detour routes could be designed for each site exclusively without
overlapping detour routes and related congestion at other damage locations.
For the initial detour routes, Caltrans and the LADOT re-timed traffic
signal at 300 intersections and installed 1,000 directional signs and
7,500 parking signs.
- In some corridors, separate detours were implemented for high occupancy
vehicles (HOVs – 2 or more persons per vehicle) and single occupancy
- Caltrans developed a transportation management plan (TMP) to handle
traffic until the damaged freeway sections were reopened. They also
implemented an Emergency Detour Management Center with emergency communications
equipment, helicopter surveillance, and traffic performance acquisition
data as well as enhanced tow service, construction zone speeding enforcements,
and park and ride lots.
- The Freeway Service Patrol was extended with 13 additional roving
tow trucks in the earthquake-affected areas. Following the Northridge
earthquake (January 17–May 1994), 90 percent, or about 15,000, of
all assists made by the FSP were on beats covering the damaged freeway
- Following the earthquake, a $12.6 million design/build contract was
put into place to install new traffic monitoring and commuter information
equipment to areas that were affected by freeway damage but were not
covered by the existing traffic operations equipment. This included
additional DMS, HAR, CCTV, and detector stations.
- The media played a large role in disseminating detour information
in the days and weeks following the Northridge earthquake. Daily press
conferences were held by members of Caltrans and FHWA to discuss the
progress of the rebuilding efforts, the status of detours in the area
and how advice for commuters to avoid earthquake damage. Newspaper inserts
and brochures were also used to inform travelers of other options.
In order to completely restore regional mobility, transportation agencies
understood that highway detours would not be enough. The Los Angeles region
would have to begin to utilize alternate transportation modes (like transit,
HOV, and telecommuting), which would be difficult in the auto-dependent
region. Transit agencies reacted quickly to the potential demand increases,
extending service and decreasing service headways in an effort to provide
mobility options to commuters. In some cases, fares were reduced. Three
new park-and-ride lots also were created at strategic locations to encourage
carpools and transit use.
Rebuilding the Los Angeles regional freeway network required a sustained
effort by Caltrans and unprecedented cooperation between local, state,
and Federal Government agencies. Through demolition, construction bidding,
and reconstruction, the agencies involved exercised innovative solutions
to existing "red tape" problems to restore the highway network.
Caltrans used emergency contracting procedures to immediately begin debris
removal and demolition activities. Caltrans was able to mobilize a demolition
contractor and crew at each of the four major damage locations. The demolition
of damaged highway infrastructure started on January 17, 1994, and operated
around the clock until completion, using non-competitive bid contractors
in all but one case.
In the first days following the earthquake, Caltrans and FHWA discussed
bidding, and eventually signed a memorandum of understanding (MOU) on
January 26, 1994, which outlined the following three bidding procedures:
- A+B Bidding is a "cost-plus-time" bidding procedure that selects
the lowest bidder based on a combination of the contract bid items (A)
and the amount time (B) needed to complete the project or a critical
portion of the project. A+B Bidding is used to motivate the contractor
to minimize the overall time on high priority and high usage projects.
This encourages contractors to finish early by offering bonuses (incentives)
for early completion and assessing fines (disincentives) for late completion.
- Invitational bidding was another procedure used to expedite contract
administration by FHWA and Caltrans. This concept was used for those
projects that had high user delay costs and an urgent need for early
completion. These projects were expected to have short time frames for
Caltrans to prepare the bid packages, greatly expedited advertising
periods for the contractors to submit bids, and one-day bid openings
and awards. Limiting the number of bidders on these critical projects
allowed Caltrans to provide packages to the contractors quickly and
- Design-build construction is another contracting mechanism that allows
initial construction to begin before final drawings for design are approved.
Following the Northridge earthquake, Caltrans had 70 design engineers
in place and ready to being work on plans for the damaged freeway sections.
Contractors submitted technical proposals for construction work, and
those proposals that met the minimum technical guidelines were allowed
to participate in the price proposal section of the bidding.
In a report published after a review of transportation decisions made
in response to the earthquake, the Transportation Research Circular (published
by the Transportation Research Board and the National Research Council)
reported several mobility findings:
- Providing immediate transportation solutions took precedence over
the opportunity to change motorist behavior.
- Stabilization of traffic conditions took several weeks to several
- Where sufficient alternate routes existed, motorists continued driving;
where convenient detours were not available, transit options became
much more attractive.
- Availability of accurate traffic data was critical in developing
- Areas with well-developed traffic management centers were able to
accommodate sudden traffic changes more easily.
12.4.2 September 11, 2001
The Terrorist attacks of September 11, 2001 exacted a terrible toll on
the United States and fundamentally changed the way of life in America.
Surface transportation has changed and continues to change in response
to the attack. Agencies that own and operate surface transportation systems
must understand the relevant lessons from the 9/11 experience and respond
accordingly so that we as a nation are well prepared should we be attached
Case studies have been developed documenting the actions taken by transportation
agencies in response to the September 11 attacks on New York City and
Washington D.C. An article in the September 2002 issue of ITE Journal
(19) synthesized the findings from both studies.
The highlights are summarized below
22.214.171.124 Advance Preparations and Planning
A coordination structure: The coordination
of local, state and federal agencies responding to an emergency is an
essential part of a pre-existing disaster plan. The Incident Command System
(ICS) is a management tool used to handle emergencies and can be adapted
to the specific needs of a community region.
Emergency response plans: Public agencies (in
both New York and surrounding states) have detailed emergency response
plans that are practiced routinely. These plans coordinate decision making
both internally and externally in conjunction with the New York City Office
of Emergency Management (OEM) (a multi-jurisdictional agency created in
Jointly staffed facilities: Agencies placed
personnel at OEM to receive and pass-on commands to their agency's emergency
response center. At agency emergency response centers, key players gathered
to make decisions and relay them back to OEM and TRANSCOM. To aid in transportation
operations decision-making during emergencies, TRANSCOM disseminated (both
internally and externally the decision of its 16 transportation and public
safety agencies so that they could make informed decisions.
Working relationships: Key decision makers
had experience in working with OEM, other transportation agencies and
the public. These relationships helped support OEM on September 11, and,
in general, gave the agencies and the public a level of confidence.
Individual initiative: Human creativity and
teamwork become critical when the unpredictable happens. Every emergency,
different in its complexity, requires personnel to make quick decisions
that may have dramatic consequences on the safety of people in the area.
The quality of the agency's staff, their ability to work together and
their preparedness at all levels of the organization to handle difficult,
changing situations is vital to a successful response.
Practice in a realistic environment: Practice
in an emergency command center environment is a key element in smooth
response to a disaster. An official at New Jersey Transit noted the importance
of practicing for emergencies, and the recognized need to train not just
the first string, but also the second and third string of employees, because
disasters do not always occur during business hours. On September 11,
a number of key transportation staff members were either lost or injured
and the responsibility for decision-making fell to others. One field staff
noted that "there was no one to talk to at headquarters; it was gone".
126.96.36.199 Institutional Coordination
Established interagency relationships: The
existence of well-established interagency relationships among the many
transportation and emergency personnel in New York was an important factor
in managing the situation. Through coordination entities such as TRANSCOM
and the OEM, agencies built effective working relationships that proved
to be a major sustaining factor during and after the crisis.
Internal command centers: Each agency, in addition
to its participation in the multi-agency task forces, had set up an internal
emergency command center. At the emergency command center, decision-makers
were able to communicate with key individuals, both internal and external
to the organization.
Coordination across agencies and jurisdictions:
Coordination between transportation agencies and their counterparts in
public safety and law enforcement was generally good, with just a few
exceptions (e.g., the failure to coordinate the release of 260,000 federal
employees and lack of notification regarding the intent to release employees
caused an unexpected rush of commuters just as the region's transportation
network was winding down from the morning peak period service pattern.)
Multiple communication technologies: Immediate
communication with agency field staff in NYC was difficult because landlines
were damaged and cellular communication systems were overloaded. Two-way
radios helped field personnel communicate during the evacuation; however,
field personnel without radio communication were out of touch.
Voice and data communication: New technologies
provided communication alternatives that proved successful in the emergency.
Internal e-mail, for example helped agencies communicate decisions with
their staff. Blackberry Pagers (interactive pagers with e-mail capabilities)
that rely on data communication technology were a successful form of communication
according to several transportation agencies.
Mobile communication assets: Agency communication
centers were also successful in supporting both internal agency decision-making
and external communication. Both NYC Transit and New Jersey Transit had
mobile communication centers (transit buses equipped with satellite and
computer technology), which were used as commend posts for communication
188.8.131.52 The Role of Advanced Technologies and Operations
ITS technologies and the associated operations have a major
impact: The following highlights a few specific examples
of ITS technologies and operations that aided both agencies and travelers
on September 11:
- Dynamic message signs and HAR were used to communicate real-time
traveler information, along with Web sites advising travelers of road
closings and transit disruptions. Both customers and facility operators
benefited in having traffic diverted before it reached the bridges or
tunnels. After TRANSCOM alerted I-95 Corridor Coalition member agencies
of problems in the New York City region, these agencies used HAR and
variable message signs (VMS) on I-95 as far south as Delaware and as
far north as New Haven to alert travelers to avoid New York City.
- CCTV surveillance was found to be very valuable for assessing the
progress and effect of traffic management operations.
- Signal system timing was reset for heavy evening rush. For example,
in Washington and in neighboring Montgomery County, computerized traffic
signal systems enabled these jurisdictions to handle the "early rush
hour" as District workers self-evacuated. Additionally, signals were
adjusted to facilitate emergency responders en-route to the Pentagon
- Ramp meters were also reset for heavy evening rush (but became a non-issue
as they are only located on routes that were quickly closed to non-emergency
- High occupancy vehicle (HOV) lanes were immediately opened to all
- Construction work zone lane closures were suspended;
- Transportation management centers served as focal points, and proved
successful in communicating and disseminating agency decisions both
internally and with the public.
- Traffic along key sections of the roadway system including bridges
leading to Manhattan was measured, and the information was used to help
determine changes in the hours of the lower Manhattan crossings SOV
184.108.40.206 Redundancy and Resiliency
Redundancy in multiple critical systems: Redundancy,
the ability to invoke backup for critical systems that fail, either partially
or entirely, is imperative to consider in emergency response. The backup
systems invoked for use in an emergency are determined by the nature and
scope of the emergency itself.
Redundancy in the transportation network: The
redundancy of the transportation system in New York helped evacuate Lower
Manhattan on September 11 and restore mobility. The automobile is only
one of many transportation options. On September 11, when the tunnels,
bridges roadways and subways were temporarily closed, local MTA buses
continued running above Canal Street, water ferries were pressed into
expanded service and people walked. The MTA was able to restore subway
service by early afternoon on September 11 because of the redundancy in
its subway tunnels.
Staff redundancy: The need for redundancy in
staffing was highlighted when several key transportation decision makers
were lost or temporarily missing in the attack. Critical decisions were
made by personnel in the field who, at times were cut off from communication
Communication redundancy: The communication
system was severely disrupted on September 11. NYC Transit was able to
use its separate system to provide landline telephone service to local,
state and federal emergency agencies when Verizon's network was disabled.
Having the option to use various technologies including two-way radio,
Internet, pagers, e-mail, voice and cell phone technologies allowed agencies
to adapt to the constantly changing landscape.
Redundant utilities: Redundant mobile generators
allowed for restoration of power to emergency control centers and allowed
agencies to begin flood prevention efforts to preserve communications
and subway tunnels from extensive water damage.
Redundant control centers: Redundant control
centers helped enormously. Even though the NYC Mayor's OEM Command Center
was destroyed when Seven World Trade Center collapsed, nearly every other
major agency in NYC had an emergency control center that swung into action
immediately. Moreover, a temporary OEM had to be re-located three times
on September 11.
In closing, Reference 19 identifies the following five
lessons learned that should be considered in future planning for emergencies
and management thereof:
1. Pre-existing relationships among agencies and personnel are
key to emergency management success. Such relationships help
transcend the different response approaches used by transportation, military,
and law enforcement agencies.
2. Preparedness planning is another crucial element,
and must include the development of an emergency response plan and training
for all shifts of workers. Planning helps establish relationships and
define roles and responsibilities. Training field personnel as well as
managers is vital, for they often must make critical decisions with little
or no input from senior staff.
3. Redundancy must be built into institutions and physical systems,
including personnel, communications, utilities, and control centers. A
new approach to redundancy is needed – a backup is not adequate if it
is also exposed to failure in an emergency. The transportation infrastructure
facilitates emergency response and evacuation, so an alternative network
is critical, as are remote backup operations and emergency management
4. Multiple technical communication methods help ensure proper
institutional communication. Redundancy and resiliency in communications
is critical. Systems that depend on cell phones or landlines can be unreliable;
an emergency response system should include both alternative technologies
and redundant network connectivity.
5. Advanced technologies play an important role in communications
and decision making. Traffic management centers, closed-circuit
TV, sensor systems, dynamic message signs, advanced traffic control systems,
Web sites, and geographic information systems were all identified as useful
in aiding internal and external communication. Timely decision-making
requires effective communication of accurate information. In the aftermath
of disaster, ITS enabled facility managers to: make informed decisions,
improve regional transportation management, and enhance communication
with the public.
1. FHWA Office of Operations / Emergency Management
Web Site http://www.ops.fhwa.dot.gov/eto_tim_pse/index.htm
2. Federal Emergency Management Agency (FEMA) Web
Site www.fema.gov ; and the website
of AASHTO's security task force at http://security.transportation.org/?siteid=65.
3. Regional Evacuation Concept of Operations; State
4. "Homeland Security and ITS – Using Intelligent
Transportation Systems to Improve and Support Homeland Security; Supplement
to the National ITS Program Plan; ITS America; September 2002
5. "A Guide to Updating Highway Emergency Response
Plans for Terrorist Incidents"; Prepared for the AASHTO Security Task
force; PB Farradyne; May 2002
6. "Manual on Uniform Traffic Control Devices" (MUTCD)
2000, Millenium Edition, Institute of Transportation Engineers, Washington,
7. "Emergency Management Guide for Business and Industry;
Available from the FEMA website
8. Wolshon, B. et al; "National Review of Hurricane
Plans and Policies"; LSU Hurricane Center; 2001
9. Department of Homeland Security (DHS) Website
10. Federal Response Plan
11. Ullman, G.L., N.D. Trout and T. Urbanik II.
Synthesis of Traffic Management for Major Emergencies. Research
Report 1231-1. Texas Transportation Institute, Texas A&M University,
College Station, 1991.
12. Florida Division of Emergency Management's (FDEM)
web site www.floridadisaster.org/index.htm
13. Guidelines for Hurricane Evacuation Studies;
US Army Corps of Engineers
14. "Best Practices for Road Weather Management
– Version 2"; FHWA; 2002
15. Wohlschlaeger, S.D. and G.L. Ullman. Catalog
of Transportation Management Activities for Major Emergencies. Research
Report 1231-2. Texas Transportation Institute, Texas A&M University,
College Station, 1991.
16. "A Guide to Highway Vulnerability Assessment
for Critical Asset Identification and Protection", Prepared for AASHTO
Security Task Force, SAIC, May 2002
17. "Effects of Catastrophic Events on Transportation
System Management and Operations: Northridge Earthquake – January 17, 1994"; U.S. Department of Transportation, John A. Volpe National Transportation
Systems Center, Cambridge, Massachusetts, April 22, 2002
18. Pierce, V.; "Surface Transportation security
Lessons Learned form 9/11"; ITE Journal; September 2002.
19. Volpe Center, "Highlights" July / August 2002,
"Improving Regional Transportation Planning for Catastrophic Events (FHWA)"