4.2.3 Infrastructure Issues
This section addresses literature found on infrastructure issues such as loss of infrastructure, monitoring of evacuation (critical routes, reverse flow), contra-flow lanes, transit assistance, use of specialty teams, use of ITS, and work zones.Some findings regarding infrastructure issues include:
The loss of infrastructure, including power, and equipment can impact evacuations.
Loss of Computer Equipment – Loss of computer equipment can impact evacuations, particularly during blackouts. According to Effects of Catastrophic Events on Transportation System Management and Operations: August 2003 Northeast Blackout Great Lakes Region: “The Road Commission for Oakland County staff maintained some computers and other essential or sensitive equipment at their Traffic Operations Center but lost all FAST-TRAC (Faster And Safer Travel Through Routing and Advanced Controls) technology of which the heart is a signal system known as the Sydney Coordinated Adaptive Traffic System which uses adaptive control technologies to regulate traffic signal timing and coordination to meet changes in vehicle demand capability in the field. Furthermore, a Road Commission for Oakland County representative explained that any ITS functionality would have been useless without signals to moderate traffic.”
Loss of Power – Loss of power also can impact evacuations. The Effects of Catastrophic Events on Transportation System Management and Operations also reports: “In general, highways can function well without electricity. However, toll collection, tunnel ventilation, lighting, pumps to control flooding, and ITS equipment such as cameras, loop detectors, and variable message systems, depend on electricity. In the Detroit area, only the Ambassador Bridge was able to maintain these types of functions.”
In addition, the publication reports: “The Michigan Intelligent Transportation System Center and its field equipment lost all power, leaving Michigan Department of Transportation staff unable to collect data, receive video feeds, or control variable message systems. They also had no telephones and had only spotty two-way communications with field staff. Like other agencies, they reported the loss of communications to be most frustrating.”
According to Learning from the 2003 Blackout, “In Cleveland, public officials were unable to use the emergency response center immediately after the start of the blackout due to a lack of backup power.”
Portable Equipment – Lack of portable equipment can also impact evacuations. Effects of Catastrophic Events on Transportation System Management and Operations: August 2003 Northeast Blackout Great Lakes Region reports:“In Oakland County, the Road Commission for Oakland County staff faced 1,300 darkened signals, with just 20 portable generators to service them. On the fly, they tried to identify the most important intersections and deployed crews to install and supervise generators at the intersections.”
Traffic Management – Standard operating procedures are used for traffic management; however, an evacuation situation can overwhelm the procedures. During standard operations, the Effects of Catastrophic Events on Transportation System Management and Operations: August 2003 Northeast Blackout Great Lakes Region reports: “Police normally respond to darkened signals first, by directing traffic if necessary until a managing agency can relieve the officer by supplying backup generation, repairing the signal, or by erecting portable stop signs. But in this case, because the [blackout of 2003] outage was so widespread, police were able to cover only a few intersections.”
Traffic Signals – Traffic signals can be impacted during an evacuation situation. According to Effects of Catastrophic Events on Transportation System Management and Operations – August 2003 Northeast Blackout Great Lakes Region, during the Great Lakes region blackout, “’one of the most immediate effects that impacted surface transportation was the loss of traffic signals. Reports indicate that drivers exhibited remarkable courtesy in treating darkened intersections as four-way stops. This treatment, however, gave no priority to major corridors, which slowed traffic everywhere to a crawl. People were taking two to three hours for trips that would normally take 15 minutes,’ according to one report. To try to relieve the congestion at key intersections, many citizens attempted to direct traffic themselves.” Redundant systems that relied upon electricity for power were inadequate.
According to Learning from the 2003 Blackout, in Cleveland, “off-duty and auxiliary police officers assisted in directing traffic, and emergency generators were later used to power some of the traffic signals.”
The literature search also found documents that address the monitoring of critical evacuation routes. For example, the publication Evacuating Florida in 2004 reports: “Florida Department of Transportation selected 50 traffic sensor locations specifically to support evacuation needs. Traffic counters provide hourly vehicle counts, average speed, historical numbers for that specific day and time; each counter senses vehicles in both directions to support the five designated contra-flow plans. Fifteen can be activated at one time and some will have live video camera view capability.”
Riding Out Future Quakes: Pre-Earthquake Planning for Post-Earthquake Transportation System Recovery in the San Francisco Bay Region details the San Francisco Bay area’s monitoring of critical routes: “California Department of Transportation, the Metropolitan Transportation Commission and the county congestion management agencies continue to work cooperatively to identify routes that are critical for life safety and emergency response, to examine routes that serve major roles in the economic recovery of the Bay Area, and to evaluate performance level needs for these routes and their structures.”
Due to its location below sea level, New Orleans is subject to flooding during severe weather such as hurricanes. The State of Louisiana monitors water levels along the major evacuation routes out of New Orleans. How the Big Easy Became the Worst Possible Hurricane Disaster details this effort: “Seven major routes are identified out of New Orleans, six subject to flooding. Louisiana uses United States Geologic Survey hydrowatch stations to monitor water levels. The stations provide real-time information, are solar-powered and transmit data to a satellite during a storm.”
Although contra-flow operations have been used with both advance-notice and no-notice evacuations, they present issues such as insufficient time to set up the operation.
Concerns with Contra-Flow Operations – Contra-flow lanes are used to add additional roadway capacity; however, there are concerns with their use. According to the ITE Journal article “Planning for the Evacuation of New Orleans”: “The benefits of contra-flow evacuation on freeways come with an increased level of risk. Freeways are designed for travel in one direction. Guidance features like signs and pavement markings may not be visible to drivers traveling in the opposite direction. Likewise, roadway safety features such as crash attenuators, guardrail transitions and breakaway support posts are not designed to provide protection from the reverse direction. There is also the risk of vehicles entering the reverse flow lanes from the ‘wrong’ direction. When these factors are combined with the stress of evacuation and the confusion that exists for drivers unfamiliar with contra flow, such operation can move from a level of inconvenience to one of danger.”
Decisions of States for Contra-Flow Operations – Contra-flow operations are not always popular with government officials. As reported in “Floyd Follies: What We've Learned,” “South Carolina officials were unprepared to reverse lanes of I-26, that is, to turn coast-bound lanes into inland-bound lanes, allowing traffic to flow faster from the storm. ‘Our decision-making was a little bit behind,’ says Jon Boettcher, hurricane coordinator with the South Carolina Emergency Management Division. After receiving blistering criticism for the stalled traffic, Governor Jim Hodges ordered lane reversals on I-26, which took several hours to complete.”
Equipment/Supplies for Contra-Flow Operations – Equipment is needed to set up contra-flow operations. According to Reverse-Laning I-65 for Hurricane Evacuations: “equipment includes dedicated traffic control equipment; fold-down signs and variable message signs. Four Alabama wreckers are stationed along the reverse-flow interstate.”
South Carolina Hurricane Evacuation Program 2003 includes “bottle water, maps, and additional port-a-lets at rest areas” among the equipment and supplies needed for the public.
In addition, a contra-flow operation needs to be communicated. The State of South Carolina Web site states, “hurricane evacuation route maps, directions and brief instructions for evacuation routes, reverse flow maps and graphics for certain intersections showing the lane reversal/changes” are provided to the general public. Additional information on communication will be presented in a later section of this report.
Guidance for Use of Contra-Flow Lanes – The use of contra-flow or one-way traffic operations is not considered lightly by public officials. According to Reverse Lane Standards and ITS Strategies Southeast United States Hurricane Study: Technical Memorandum Number 1: Final Report, “Florida uses a checklist to guide senior managers in the decision process. All three states (Florida, Georgia and South Carolina) agreed that a one-way operation (contra-flow) should be used for category 3 and up hurricanes.” In addition, contra-flow lanes need to be long enough to move people out of the critical path; this could range from 80 to 100 miles away from the event site. During an evacuation, people may not need to move that great of a distance, or they may need only move far enough to clear the event site, which could be just a few miles away.
Setting Up Contra-Flow Operations – Setting up contra-flow operations varies from state to state and locale to locale. For the State of Alabama, Reverse-Laning I-65 for Hurricane Evacuations reports: “Time to implement—approximately four hours for Alabama Department of Transportation employees to report to assigned location once Stage One is called into effect (notification time and travel time). Approximately one hour for Alabama Department of Transportation employees to complete implementation of the plan and have reversed-flow traffic moving. Evacuation should be complete and plan removed prior to storm landfall and/or nightfall.”
According to South Carolina Hurricane Evacuation Program 2003, the State of South Carolina “requires two hours to place barricades, [and] requires two hours to flush traffic.”
According to Reverse Lane Standards and ITS Strategies Southeast United States Hurricane Study: Technical Memorandum Number 1: Final Report, the time for setting up contra-flow operations for the State of North Carolina takes 3 to 4 hours, depending on the corridor, to set up and upwards to 12 hours to mobilize the National Guard [to assist in the evacuation].
Contra-flow operations are geared towards massive evacuations of people with time available to set up the operation. In a no-notice situation, time may be unavailable to set up a contra-flow operation.
Tunnel Contra-Flow Operations – Decisions made prior to an evacuation may impact evacuation efforts. As reported in Learning from the 2003 Blackout, “In New York, tunnel managers made several key decisions throughout the blackout. One was to close some traffic lanes within some tunnels. Because the facilities' ventilation systems require an excessive amount of power, managers previously had decided not to connect them to the backup system. Therefore, the tunnel operators had to reduce the number of cars allowed through at any one time to decrease the pollutants. Some bridge and tunnel operators reversed one lane so that there would be three lanes for traffic leaving Manhattan and one for vehicles entering the area.”
Types of Contra-Flow Operations – Traffic strategies have been developed for hurricane evacuations that involve moving massive numbers of people. According to Reverse Lane Standards and ITS Strategies Southeast United States Hurricane Study: Technical Memorandum Number 1: Final Report, these strategies include:
Use of Contra-Flow Operations – Transportation measures have been identified for hurricane evacuations that assist in accelerating evacuations. TR News: Emergency Evacuation: Ensuring Safe and Efficient Transportation out of Endangered Areas reports: “Recent evacuations have failed to take full advantage of the obvious counterpart to limiting demand—maximizing the use of the available transportation infrastructure. One technique to increase evacuation capacity is the use of contra-flow freeway segments—reversing one or more lanes or shoulders in the inbound direction for use by outbound traffic. Preliminary studies have shown that contra-flow strategies can increase the outbound volume by about 70 percent. Other methods of infrastructure maximization include the coordination of traffic controls on parallel, non-freeway routes; the use of mass transit systems; and limiting the interruptions to evacuation flow at railroad crossings and drawbridges.” However, setting up contra-flow lanes takes time, which may not be available for no-notice evacuations.
In New Orleans, contra-flow lanes have been developed. The article “Planning for the Evacuation of New Orleans” describes their development: “To accelerate the flow of evacuees out of the city, local and state emergency planning and transportation officials in Louisiana have developed an evacuation plan that includes the reversal of freeway routes into the city. Under this plan, traffic flow on some or all of the inbound lanes of the freeways into the city will be reversed to flow in the outbound direction. These ‘contra flow evacuations’ were used during Floyd in both Georgia and South Carolina with mixed success.”
Recently, the State of Louisiana used contra-flow operations during Hurricane Ivan (2004). The Natural Hazards Observer article “What If Hurricane Ivan Had Not Missed New Orleans?” reported: “To aid in the evacuation, transportation officials instituted contra flow evacuation for the first time in the area’s history whereby both lanes of a 12-mile stretch of Interstate 10 were used to facilitate the significantly increased outbound flow of traffic toward the northwest and Baton Rouge. The distance of the contra flow was limited due to state police concerns about the need for staff to close the exits.’‘although [Louisiana] officials were initially pleased with the results, evacuees felt the short distance merely shifted the location of the major jams…it took residents up to 11 hours to go the distance usually traveled in less than 1.5”. Evacuation to Texas frequently exceeded 20 hours. Since the storm, the consensus of the Louisiana experience was that “to alleviate this congestion (a) much more secondary highway coordination was necessary throughout the state, (b) contra flow needs to be considered for much greater distances, (c) residents who are able and willing to evacuate early must be doubly encouraged to do so, (d) families with multiple cars need to be discouraged from taking more than one unless they are needed to accommodate evacuees, and all (e) modes of transportation must be fully considered for the contributions they can make to a safe and effective evacuation.”
February 7, 2006
United States Department of Transportation – Federal Highway Administration
Last Modified: January 15, 2021