Click for next page ( 30

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 29
29 promotes the functions that respond to incidents that affect experienced cancellations or reductions from any of the pro- traffic on the interstate system, provide safety alerts to oncom- gram sponsors. ing traffic, provide temporary maintenance of traffic to the Continued expansion of the program is one of the future incident scene, and clear the road of incidents. Road Ranger challenges for FDOT. Typically, freeways need to reach a criti- patrols help distressed motorists on the interstate because these cal level of congestion or show a high crash rate to receive rov- motorists create a situation that is a traffic hazard that could ing Road Ranger patrols. FDOT is continuing to seek funding compromise safety, cause delays because of onlookers, and dis- sources to allow for expansion of the Road Ranger program. tract motorists, which often leads to secondary incidents. There are clear benefits to having the service patrols operate on The relationship and cooperation between FDOT and FHP freeways even if congestion is not at peak levels. FDOT would have been good, and the benefits of the Road Ranger program like to find ways to expand the program and bring the proven to both agencies is clearly understood. One challenge has been benefits of Road Rangers to an expanded area of Florida in the in interoperable communications between FHP officers and near future. Road Ranger operators in the field. Interoperable communi- cation is especially important during major incident response, United Kingdom: Active when Road Rangers may be managing traffic several miles Traffic Management away from the actual incident scene itself. FHP officers and Road Ranger operators used to relay messages through their Active traffic management (ATM) is a method of managing respective dispatchers to communicate in the field. Interoper- traffic through a dense deployment of technology applica- able 800-MHz radios are being implemented by FDOT and tions that reduces congestion and improves traffic flow. This was set to be fully implemented by the end of 2009. The radios method focuses on improving travel reliability, enhancing would then allow direct field communications and reduce the efficiency, and increasing throughput and safety along the amount of time and potential for erroneous messages to be existing roadway. ATM is based on several new or modified conveyed. operational strategies that together produce a fully managed corridor, optimizing the existing infrastructure along the road- way. Currently, ATM is used in a number of European coun- Analysis and Research Observations tries, including Denmark, Germany, the United Kingdom, and The Road Ranger program has been successful in part because the Netherlands. In addition, several states are in the process of it fulfills a critical incident management need, and is the result implementing some elements of the ATM practice and tech- of several years of grassroots efforts before expanding statewide. nologies to enhance their current networks. Service patrols were implemented in Florida over 20 years ago The United Kingdom initiated a pilot program along M42, to assist with work zones and later expanded to include cover- southeast of Birmingham, England. The program consists of age of I-75 through the Everglades to assist stranded motorists gantries, detection, variable speed limit (VSL) signs, cameras, in an area with little amenities. The service patrol on I-75 and variable message signs (VMS) along a 10.5-mi section. The through the Everglades relieved FHP of the burden of assist- Regional Control Center (RCC) in the area, West Midlands ing motorists on a stretch of road where the FHP patrols were Regional Control Center, actively operates the ATM deploy- already sparse. By the time the Road Ranger program was ment. The success of the pilot project has generated significant expanded statewide and implemented across Florida, there was benefits that have led to the support and funding for an exten- strong buy-in from FDOT, FHP, and many of the tow vendors sive expansion of the ATM project to over 300 mi (10). who saw the benefits of service patrols in work zones. FDOT David Grant, the group manager and head of ATM within continued to monitor the benefits of the Road Ranger pro- the Highways Agency (HA) was interviewed for this case study. gram through an ongoing performance measurement effort, The HA is an executive agency within the Department for customer surveys, and a benefit-cost analysis by the Center for Transport of the United Kingdom. It manages traffic and Urban Transportation Research. Early buy-in from FDOT and congestion, provides information, and improves safety. FHP, coupled with continual measurement of the performance and benefits of the Road Ranger program, have been key to Description its success. Private sponsorship of the Road Ranger program was needed This case study investigates how ATM practices and technolo- in 2008 to supplement the service due to budget reductions. gies are used to improve travel time reliability. HA took a dif- FDOT was able to get the support of private sponsors by allow- ferent approach to designing and developing its ATM program ing them to tie their name to a program with a proven track by conducting a safety analysis of the corridor. Based on the record of great customer service and strong public support. identified safety issues, mitigation strategies were determined Even with the slow economy in 2008 and 2009, FDOT has not and packaged into the ATM solution for the corridor. The

OCR for page 29
30 work completed during the safety analysis provided before- to each hazard were identified. Data in several areas including data that could be used to calculate actual benefits of the fully safety, traffic conditions (mobility), noise, and user perspec- implemented pilot project. After the M42 ATM deployment tive were documented so the benefit of ATM strategies could was in operation for 12 months, a private firm was hired to be evaluated appropriately and to guide future decisions for review its effectiveness and document its benefits. These docu- the HA (11). mented benefits were used to gain support for funding of a full The pilot project was designed and construction began in ATM program, including extending ATM to all seven regions March 2003. It included variable speed limit (VSL) signs, emer- in England. gency refuge areas (ERA), hard shoulder running, vehicle detec- The UK case study was selected because of its excellent doc- tion, and VMS. One of the larger concerns of the pilot project umentation of benefits and because of the analytical approach was user compliance; HA needed to verify that motorists would it used to define the components of the ATM pilot project. comply with variable speed limits. To address this issue, HA used specially developed digital cameras to enforce the variable speed limits. HA was not concerned with the monetary penal- Background of Agency ties received, but with the impact on reducing the safety risks The HA is responsible for operations, maintenance, and of those who are speeding. improvements of approximately 5,500 mi of strategic road- Another issue that HA considered was the accuracy and ways, or trunk roads, within England. Over 105 billion vehicle timeliness of the messages provided. The message signs are miles are travelled along the roadways each year. The HA has used to give travel information or detour routes during severe eight transportation control centers throughout the region to incidents. If the information is not consistent or current on the monitor traffic. The National Traffic Control Center (NTCC) VMS, drivers likely would stop heeding the messages, thereby near Birmingham is the main hub for travel information within affecting the impacts of the overall ATM solution. England. The NTCC is used to relay information to motorists along Detailed Process the national network. NTCC provides continuous information about incidents, notification of congested sections, and alerts The process used for managing an incident using ATM is concerning severe weather that may affect the roadway. The displayed in Figure 3.3. When an incident occurs, the RCC other seven regional control centers (RCC) are used for tacti- receives notification through various means, including data cal issues along the roadway. They dispatch support to disabled collected by the detection equipment and cellular phone calls vehicles, help clear incidents, provide traffic management sup- to the police agency. RCC operators continually monitor the port, and operate ATM deployments. Currently, only one of roadway from cameras located along the corridor and can ver- the regional facilities has ATM in its jurisdiction, but eventu- ify the incident location and severity. ally, all seven will operate some level of ATM. The role of the police at any roadway incident is for investi- The NTCC uses a variety of technologies to monitor traffic gation only; they do not play a role in traffic management. Uni- along the HA network. Some of the technologies include traf- formed traffic officers run the control room and can dispatch fic flow monitoring equipment, cameras (including automatic personnel to the scene. In the West Midlands RCC, the police number plate recognition [ANPR]), vehicle sensors or detec- also share the control room and can dispatch units to a serious tion, and floating car technology. This information is relayed incident. Traffic officers are personnel that help monitor and to a variety of traveler information tools, which include Traf- patrol the roadway network. When the detection deployment fic England (traveler information website), kiosks, VMS, and acknowledges a change in the traffic flow, the VSL signs are the media. automatically adjusted to slow the approaching traffic and reduce the risk of rear-end crashes. This integration allows RCC to monitor the incident and activate the gantry signals to Process Development move traffic out of the affected lane. VMS also are activated In 2000, The UK government's Transport 2010 strategy from RCC to divert traffic onto alternate routes and alert traf- included the idea of an ATM solution. After a comprehensive fic of the upcoming incident. RCC closely monitors and con- review of five potential sites (including M25, London's Orbital tinues to divert additional traffic, if warranted, in conjunction Motorway), the M42 was selected for a pilot study. The HA with the NTCC. performed a safety evaluation of M42 during 2002 and 2003. Traffic officers are tasked with providing onsite traffic man- The safety analysis identified over 2000 new and existing safety agement, such as full ramp closures, to supplement the ATM issues on the corridor. A risk assessment was performed for and protect the incident scene for the police. Traffic officers are each hazard type to determine the probability of occurrence. strategically located in depots adjacent to the road network so The impacts were reviewed and mitigation strategies specific they can easily be dispatched by RCC operators along with

OCR for page 29
31 Figure 3.3. Detailed business process diagram of United Kingdom active traffic management. emergency response personnel (i.e., fire and first responders) to continue sharing updates on traffic flow. The VSL signs will and the police. Based on the observed incident location and automatically adjust to higher speeds as the traffic flow regains severity, the RCC operators activate messages on the VMS to capacity and speeds slowly increase. share information concerning the incident and to manage lane Several key integration points were identified in the ATM use of approaching traffic. incident management process, including the following: In addition, ERAs have been installed to assist in quickly clearing incidents and stalled vehicles from the hard shoulder. Integration between NTCC and the regional control centers These locations also provide safe and easy access for mainte- to monitor incidents and to activate devices, respectively; nance of the ATM field devices. ERAs include phones with Integration between NTCC and the traffic officer service, multilingual, hearing loops, and texting capabilities. The refuge emergency response, and the police; areas improve safety and capacity by providing a location for While monitoring the incident location, the on-road traffic travelers and maintenance personnel to move off the hard officer service integrates with the RCC; and shoulder and out of the roadway. Integration between the RCC operator and the field devices. Once the incident has been cleared, the RCC operators will evaluate the safety of the roadway and decide when to reopen The process is documented in a 12-month performance traffic lanes. Once the operators decide the roadway is safe, the report about the project, the process, the outcomes, and devices are reset to normal operations and the VMS are used the benefits (12). The HA website also contains comprehen-

OCR for page 29
32 sive information about the ATM pilot project. This informa- it in the previous three months of the survey), and long- tion includes details of the project scope, funding, how ATM distance users. They surveyed the users' thoughts about the manages traffic, and the results. ATM modifications, specifically as they pertain to conges- In addition, all incidents require a report. The complexity tion along the corridor, the ATM measures, environmental of the report depends on the severity of the incident. A more impacts, enforcement, driver information, and overall use of severe incident requires a larger number of agencies involved the corridor. with investigation and clearance and is therefore more com- It was understood that users need to have reliable, accurate plex. Some severe incidents also require debriefings with the information displayed at all times to trust the message at a agencies involved. given time. The operators within the control centers are con- stantly monitoring the flow of traffic along the corridor to Types of Agencies Involved ensure that what is happening on the roadway is being dis- played. Based on effective operations of ATM, the motorists on There were more than 120 stakeholder groups that provided M42 have experienced a 27% improvement in travel time vari- input to guide the development of the ATM system. HA is one ability and a 24% improvement in travel times during the of seven executive agencies within the Department for Trans- worst pm peak. The ATM pilot project also has resulted in a port that is responsible for ATM and has led the effort since its 4% decrease in fuel consumption; a 10% decrease in vehicle inception. Another significant supporter of ATM is the Freight emissions; and a decrease in the crash rate from 5.1 to 1.8 per Transport Association. Trunk roads connect the ports with month (12). inland delivery destinations and therefore have a significant impact on freight operations. Benefits Types of Nonrecurring Congestion Addressed The ATM pilot project demonstrated several congestion and safety benefits along the M42 corridor. The documentation This ATM pilot project was developed to address recurring and of these benefits has helped to gain the support of govern- nonrecurring congestion. ATM is used to alert travelers of any ment ministers and industry. As stated, the benefits include incident occurring along the corridor by means of VSL signs, improvements in travel time, emission and fuel consumption vehicle detection, and VMS. Advanced capabilities of the sys- reduction, and a decrease in the crash rate. These benefits are tem provide technology and infrastructure to address all forms due in large part to the overwhelming compliance rate of the of nonrecurring congestion on the corridor. Before implemen- tation, congestion on M42 was so severe that motorists were drivers. regularly experiencing stop-start conditions. However, as con- Driver compliance with VSL signs and VMS was a concern gestion continued, safety improved. Because of lower average before implementing the pilot project. However, HA has doc- travel speeds, crashes often did not involve any fatalities or umented a 95% compliance rate for speed limits equivalent to severe injuries. 50, 60, and 70 mph and an 85% compliance rate for speed lim- Before ATM was implemented and an incident occurred, its equivalent to 40 mph (12). the impact on capacity was severe, with impacts lasting for Another benefit of the ATM project is the lower cost and several hours. Travel time along the corridor was extremely reduced schedule compared to a road widening project. Widen- volatile, ranging from 30 min to 3 h. Use of arterials was lim- ing of the corridor by one additional lane was estimated to cost ited because of the lack of traffic management strategies and about $820 million, take 8 to 12 years to complete, and would limited coordination with local agencies. The pilot project pro- require an environmental statement and public involvement. vided the regional center with comprehensive monitoring and The ATM pilot project cost only $160 million and was complete traffic management strategies along the 10.5-mi corridor. This within 3 to 4 years, with no environmental impacts or need for coordination has significantly improved impacts related to additional right-of-way. nonrecurring congestion. Finally, the benefits demonstrated from the pilot project provided sufficient documentation to support funding for project expansion. In January 2009, government ministers Performance Measures announced that a $10 billion project, Managed Motorways, As mentioned, HA hired a consultant to evaluate and docu- was initiated to expand ATM to over 300 roadway miles. The ment the impacts of ATM on the roadway network. The con- expansion will provide ATM coverage across England, with sultant conducted surveys with local users, local nonusers ATM control being conducted from all seven regional control (those who live near the roadway but have not traveled on centers.