Intelligent
Transportation Systems Benefits and Costs 2003 Update PDF Version 30.0MB Prepared byMitretek Systems 600 Maryland Avenue, SW, Suite 755 Washington, DC 20024 Under Contract to the Federal Highway Administration United States Department of Transportation Washington, DC May 2003
PREFACEFor the first time, the U.S. Department of Transportation (DOT) is presenting in one document benefits and costs information for Intelligent Transportation Systems (ITS) implementations. Intelligent Transportation Systems Benefits and Costs 2003 Update represents a culmination of DOT's active 10-year data collection on the impact of ITS projects on surface transportation and the cost of implementing them. This compendium builds on previous ITS benefits reports, and refers the reader to information sources. As a public service, DOT also sponsors a regularly updated online ITS Benefits and Unit Costs Database at www.benefitcost.its.dot.gov, which gives transportation professionals the information they need about benefits and costs of ITS implementations and services. The database also gives researchers information on ITS areas where further analysis may be required. The printed 2003 Update (FHWA Report FHWA-OP-03-075) can be ordered by writing to itspubs@fhwa.dot.gov. It can be viewed on DOT's ITS Electronic Document Library at www.its.dot.gov/itsweb/welcome.htm as document No. 13772_files. Not all ITS efforts initiated by states, local governments, and private enterprises are documented in the 2003 Update or in the database. We encourage readers who are aware of ITS benefits and costs information from these and other sources to let us know about them by using the online database or by sending reference documents to:
Joseph I. Peters, Ph.D. TABLE OF CONTENTSExecutive Summary1.0 Introduction 1.1 Benefits Database Goals and Overview 1.2 Unit Costs Database Goals and Overview 1.3 A Few Good Measures 1.4 Report Organization 2.0 Benefits and Costs of the Intelligent Infrastructure 2.1 Arterial Management Systems 2.2 Freeway Management Systems 2.3 Transit Management Systems 2.4 Incident Management Systems 2.5 Emergency Management Systems 2.6 Electronic Payment Systems 2.7 Traveler Information 2.8 Information Management 2.9 Crash Prevention & Safety 2.10 Roadway Operations & Maintenance 2.11 Road Weather Management 2.12 Commercial Vehicle Operations 2.13 Intermodal Freight 3.0 Benefits and Costs of Intelligent Vehicles 3.1 Collision Warning Systems 3.2 Driver Assistance Systems 3.3 Collision Notification Systems 4.0 Summary and Conclusions References Appendix A: ITS Unit Costs Database Appendix B: List of Acronyms LISTING OF TABLESTable 1.0.1 Definition of Impact Ratings for Assessment of ITS ApplicationsTable 2.1.1 Benefits and Costs of Arterial Management Systems Table 2.2.1 Benefits and Costs of Freeway Management Systems Table 2.3.1 Benefits and Costs of Transit Management Systems Table 2.4.1 Benefits and Costs of Incident Management Systems Table 2.5.1 Benefits and Costs of Emergency Management Systems Table 2.6.1 Benefits and Costs of Electronic Payment Systems Table 2.7.1 Benefits and Costs of Traveler Information Table 2.8.1 Costs of Information Management Table 2.9.1 Benefits and Costs of Crash Prevention & Safety Table 2.10.1 Benefits and Costs of Roadway Operations & Maintenance Table 2.11.1 Benefits and Costs of Road Weather Management Table 2.12.1 Benefits and Costs of ITS for Commercial Vehicle Operations Table 2.13.1 Benefits and Costs of ITS Applications for Intermodal Freight Table 3.1.1 Benefits and Costs of Collision Warning Systems Table 3.2.1 Benefits and Costs of Driver Assistance Systems Table 3.3.1 Benefits and Costs of Collision Notification Systems Table 4.0.1 Documents Available in the ITS Benefits Database Table 4.0.2 Summary of Benefits Sources/References and System Cost Data LISTING OF FIGURESFigure 1.4.1 Taxonomy for ITSFigure 1.4.2 Taxonomy for the Intelligent Infrastructure Figure 1.4.3 Taxonomy for Intelligent Vehicles Figure 1.4.4 Excerpt of Table 2.1.1 (describing benefits and costs of Adaptive Signal Control) Figure 2.0 Taxonomy for the Intelligent Infrastructure Figure 2.1.1 Taxonomy for Arterial Management Systems Figure 2.2.1 Taxonomy for Freeway Management Systems Figure 2.3.1 Taxonomy for Transit Management Systems Figure 2.4.1 Taxonomy for Incident Management Systems Figure 2.5.1 Taxonomy for Emergency Management Systems Figure 2.6.1 Taxonomy for Electronic Payment Systems Figure 2.7.1 Taxonomy for Traveler Information Figure 2.8.1 Taxonomy for Information Management Figure 2.9.1 Taxonomy for Crash Prevention & Safety Figure 2.10.1 Taxonomy for Roadway Operations & Maintenance Figure 2.11.1 Taxonomy for Road Weather Management Figure 2.12.1 Taxonomy for Commercial Vehicle Operations Figure 2.13.1 Taxonomy for Intermodal Freight Figure 3.0.1 Taxonomy for Intelligent Vehicles Figure 3.1.1 Taxonomy for Collision Warning Systems Figure 3.2.1 Taxonomy for Driver Assistance Systems Figure 3.3.1 Taxonomy for Collision Notification Systems EXECUTIVE SUMMARYThe increasing demand for travel by highway and public transit in the United States is causing the transportation system to reach the limits of its existing capacity. Intelligent Transportation Systems (ITS) can help ease this strain through the application of modern information technology and communications. ITS include a wide collection of applications, from 511 telephone traveler information systems to freeway ramp metering systems and electronic transit fare payment systems. In order to apply ITS services most effectively, it is important to understand their benefits and costs. The diverse array of ITS applications available can address a variety of transportation problems. Some applications provide more cost-effective benefits than others, and as technology evolves, the available choices change. The costs of these technology investments—not only the first-time, initial costs, but the costs to operate and maintain them—are of interest to transportation agencies. This report is a continuation of a series of reports providing a synthesis of the information collected by the United States Department of Transportation's (U.S. DOT) ITS Joint Program Office (JPO) on the impact that ITS projects have on the operation of the surface transportation network. New in this 2003 report is the inclusion of cost information for representative ITS deployments; previous reports contained only benefits information. Information in this report is drawn from the ITS Benefits and Unit Costs Database, a regularly updated repository of such information, available on the Internet at www.benefitcost.its.dot.gov. The report presents material from the database that describes the impacts of the intelligent transportation infrastructure as well as intelligent vehicle applications. The majority of published evaluations of ITS implementations document positive impacts on the transportation system, and the assessments provided in this report reflect this fact. However, every attempt has been made to incorporate positive, negative, and neutral findings. A small number of negative findings appear in this report; for example, Section 2.6 documents increases in crashes at toll plazas with electronic toll collection, likely due to driver uncertainty regarding plaza configuration and the variations in the speeds of vehicles within the plazas. This report also documents a few evaluations which found that an ITS implementation did not have an impact on a particular measure of effectiveness, including two studies that found traveler information does not have a significant impact on capacity, while it does reduce traveler delay. Mixed results are also noted in the few instances where studies have found both positive and negative impacts in a given area. There is a continuing need for ongoing evaluation of ITS, as indicated by the large number of application areas within this report for which there are not enough evaluation data to make an assessment of the system's impact on many of the relevant performance measures. The remainder of the Executive Summary provides representative samples of the information in the main body of the report. The body of this report includes additional detail on the impacts and costs of many applications within the wide variety represented by the major ITS program areas. The concluding section of this report contains a summary of the availability of benefits and costs data for the various ITS applications and points out the gaps that still remain. The following pages contain brief descriptions of the 16 ITS program areas discussed, as well as highlights of the benefits and costs information available for each.
1.0 INTRODUCTIONHighway travel by Americans continues to grow as population increases, particularly in metropolitan areas. Construction of new highway capacity to accommodate this growth in travel has not kept pace. Between 1980 and 1999, vehicle miles of travel increased 76 percent while road expansion to meet this demand has lagged behind. The Texas Transportation Institute estimates that, in 2000, the 75 largest metropolitan areas experienced 3.6 billion vehicle-hours of delay, resulting in 5.7 billion gallons in wasted fuel and $67.5 billion in lost productivity. 37 Transit ridership is also on the rise, reaching 9.4 billion trips in 2000, the highest level in 40 years. 38 Freight volumes are forecast to grow by about 69 percent between 1998 and 2020, from 15.3 billion tons, to 25.8 billion tons annually. 39 Largely considered a big-city problem, congestion and related delays are becoming increasingly common in small cities and some rural areas as well. This increasing demand for transportation is causing the transportation system to reach the limits of its existing capacity. Intelligent Transportation Systems (ITS) can help ease this strain through the application of modern information technology and communications. The goal of ITS is to improve the transportation system to make it more effective, efficient, and safe. Building new transportation infrastructure is expensive and can be detrimental to the environment. In most urban areas where more capacity is needed, it is becoming physically impossible to build enough new roads or new lanes to meet transportation demand. By applying the latest technological advances to our transportation system, ITS can help meet increasing demand for transportation by improving the quality, safety, and effective capacity of our existing infrastructure. ITS represents a wide collection of applications, from advanced traffic signal control systems, to electronic transit fare payment systems, to ramp meters, to collision warning systems. In order to apply ITS services most effectively, it is important to understand their benefits and costs. Some applications provide more cost-effective benefits than others, and as technology evolves, the choices available change. Often, several technologies are combined in a single integrated system, providing a higher level of benefits than any single technology. The costs of these technology investments not only the first-time, initial costs, but the costs to operate and maintain them are of interest to transportation agencies. 
This report is a continuation of a series of reports providing a synthesis of the information collected by the United States Department of Transportation's (U.S. DOT) ITS Joint Program Office (JPO) on the impact of ITS projects on the operation of the surface transportation network. The last report, ITS Benefits: 2001 Update, 40 was published in June of 2001. New in the 2003 report is the inclusion of cost information for representative ITS deployments. Information in the report is drawn from the ITS Benefits and Unit Costs Database, a regularly updated repository for this information, available on the Internet at www.benefitcost.its.dot.gov. The report presents material from the database according to program areas within the intelligent transportation infrastructure as well as those within the intelligent vehicle area. Also provided are example system costs from deployments within many of the program areas, as well as relevant unit cost data for components of the various applications. New in the 2003 report is the inclusion of cost information for representative ITS deployments. This report presents an assessment of the effect of ITS applications on several important impact areas. These assessments are built from findings in the benefits portion of the database, incorporating additions since the completion of the last report. While the assessments are based on the authors' review of all study findings, the highlighted examples are only a portion of the total number of studies documented in the ITS Benefits Database. The impact assessments for each ITS application area are presented through a rating system, as shown in Table 1.0.1. These ratings were developed through individual review of the database content by the authors, with additional discussion among the authors to establish the final ratings presented in this report. A particular rating was assigned if one or more of the reasons in the rationale column in Table 1.0.1 was evident in reviewing the evaluations of a given ITS application in the Benefits Database. TABLE 1.0.1
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| Symbol | Impact Rating | Rationale |
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| ++ | substantial positive impacts |
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| + | positive impacts |
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| o | negligible impact |
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| +/- | mixed results |
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| ? | not enough data |
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| - | negative impacts |
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The majority of published evaluations of ITS implementations document positive impacts on the transportation system, and the assessments provided in this report reflect this fact. However, every attempt has been made to incorporate positive, negative, and neutral findings. A small number of negative findings appear in this report: for example, Section 2.6 documents increases in crashes at toll plazas with electronic toll collection, likely due to driver uncertainty regarding plaza configuration and the variations in the speeds of vehicles within the plazas. This report also documents a few evaluations which found that an ITS implementation did not have an impact on a particular measure of effectiveness, including two studies that found traveler information did not have a significant impact on capacity, while it did reduce traveler delay. Mixed results are also noted in the few instances where studies have found both positive and negative impacts in a given area. There is a continuing need for ongoing evaluation of ITS, as indicated by the large number of application areas within this report for which there are not enough evaluation data to make an assessment of the system's impact on many of the relevant performance measures.
Interested readers are encouraged to check the database from time to time for the latest findings on the benefits and costs of ITS. This report is intended to be a reference report; it highlights impacts and system cost data identified by other authors. The interested reader is encouraged to obtain source documents to appreciate the assumptions and constraints placed upon interpretation of results. This interactive report includes links from sections of the report to relevant portions of the ITS Benefits and Unit Costs Database. Within the data tables provided for the various ITS application areas, "Benefits" links provide access to relevant documents in the Benefits database, and the Unit Cost subsystem entries provide links to the related portions of the database. The database includes more detailed summaries of the evaluations cited in this report as well as links to source documents, when available online.
While this report focuses on documenting and assessing the impacts of ITS implementations on the transportation system as well as the costs of these implementations, the ITS JPO has also published a number of other documents to convey lessons learned in the implementation of ITS. The report, What Have We Learned About Intelligent Transportation Systems?, published in 2000, contains a more comprehensive examination of which ITS technologies have been successful over the 10-year history of the National ITS Program, which ITS technologies have not been successful, and what are the underlying factors that determine success or failure.41
The ITS JPO's website is another valuable resource for information on the various applications of ITS. The website, http://www.its.dot.gov, also includes links to many of the resources highlighted within this report, including an electronic document library, which contains electronic copies of many of the reports made available by the JPO.
In addition, for those ITS technologies with a well-established track record, the U.S. DOT has developed a series of reports that help decision-makers learn about how those ITS solutions can address local and regional transportation needs. There are several different types of reports in the series, each designed to communicate with target audiences at various levels:
- ITS Benefits Brochures let experienced community leaders and transportation professionals explain in their own words how specific ITS technologies have benefited their areas.
- Cross-Cutting Studies examine various ITS approaches that can be taken to meet a community's goals.
- Case Studies provide in-depth coverage of specific approaches taken by communities across the U.S.
- Implementation Guides serve as "how to" manuals to assist project staff in the technical details of implementing ITS.
- Technical Reports are easy-to-read excerpts from more detailed evaluation reports.
In addition to lessons learned and other reports developed to assist transportation decision-makers, information is available on how much and what types of ITS deployment have taken place. The ITS Metropolitan Deployment Tracking project began in 1996 with the goal of tracking the level of ITS deployment and integration in 75 of the nation's largest metropolitan areas. The number of metropolitan areas was later increased to 78. In 1997, and again in 1999 and 2000, data were collected based on a series of surveys targeted at 78 of the largest metropolitan areas. Beginning in 2002, the target areas were expanded to include 30 medium-sized, high-congestion areas, 20 tourist areas, and 50 statewide/rural areas. Results of the data collected for 2002 will be available at the ITS Deployment Tracking web site, www.itsdeployment.its.dot.gov, in early summer 2003.
1.1 BENEFITS DATABASE GOALS AND OVERVIEW
To expand the understanding of ITS benefits, the U.S. DOT's ITS JPO has been actively collecting information regarding the impact of ITS implementations over the past decade. In support of this effort, the JPO sponsored the development of the ITS Benefits Database. The database is available to the public at www.benefitcost.its.dot.gov. The database contains the most recent data collected by the JPO. Its purpose is to transmit existing knowledge of ITS benefits to the transportation professionals. The database also provides the research community with information on ITS areas where further analysis may be required.
The Benefits Database website contains detailed summaries of each of the ITS evaluation reports reviewed by the JPO that met the acceptance criteria. Summaries on the web pages provide additional background on the context of the evaluations, the evaluation methodologies used, and links to the source documentation (when available online). While the JPO publishes reports such as this periodically, the online database is updated quarterly to reflect the most recent reports reviewed. Documents reviewed for inclusion in the database include the results of federal evaluation projects, as well as papers, journal articles, and state or local evaluation reports identified through review of conference proceedings and journals, or through e-mail submission via the website. The collection of evaluation reports is an ongoing program, and readers are encouraged to submit relevant documents via the database website.
The online database also provides several capabilities to simplify access to information relevant to a researcher's interest. In addition to using the classification system in this report, interested researchers can access document summaries classified by project location and ITS goal areas addressed in the evaluations, or search the database for relevant keywords. These capabilities of the online database simplify access to the most recently available data on ITS benefits identified by the JPO. The website also contains a discussion of the criteria and sources used to determine whether or not a report should be added to the ITS Benefits Database.
1.2 UNIT COSTS DATABASE GOALS AND OVERVIEW
The ITS JPO also collects information on ITS costs, and maintains this information in the ITS Unit Costs Database. The database, a companion to the Benefits Database, is available to the public at the same website, www.benefitcost.its.dot.gov, (and also presented in Appendix A). The database is a central site for ITS cost data and is based on the most recent data collected by the JPO. Its purpose is to make cost data available to public and private organizations. The database also provides data that the ITS JPO can use for programmatic and policy decisions, and education of ITS stakeholders.
The ITS Unit Costs Database consists of a range of reported costs for a set of ITS elements. The cost data are organized by "subsystem" and generally follow the structure of the National ITS Architecture. The cost estimates are categorized as capital and operating and maintenance (O&M) costs. Capital costs are the costs expended for one-time, non-recurring purchases. Operations and maintenance costs, often referred to as recurring costs, are the annual costs incurred on an ongoing basis. Costs are presented in a range to capture the lows and highs of the cost elements from the different data sources. A "Notes" field provides a brief narrative describing the particular unit cost element and its components. The cost data are useful in developing project cost estimates during the planning process. However, the user is encouraged to find local/regional data sources and current vendor data in order to perform a more detailed cost estimate.
Currently, example system costs from deployments are not contained in the Unit Costs Database or on the website. The collection of cost data is an ongoing program, and readers are encouraged to submit relevant cost data (and benefits data) via the database website. As new cost data become available, existing costs for the unit cost elements will be revised and new unit cost elements will be added.
1.3 A FEW GOOD MEASURES
In the spring of 1996, the ITS JPO established a set of ITS program goal areas directly related to the ITS strategic plan.42 The goal areas include improving traveler safety, improving traveler mobility, improving system efficiency, increasing the productivity of transportation providers, and conserving energy while protecting the environment. The JPO also identified several measures of effectiveness to evaluate the performance of ITS services in each goal area. The measures are known as the "Few Good Measures" and are intended to enable project managers to gauge the effects and impacts of ITS. The following is an overview of the various measures of effectiveness within each goal area.
Safety
An explicit objective of the transportation system is to provide a safe environment for travel while continuing to strive to improve the performance of the system. Although undesirable, crashes and fatalities are an inevitable occurrence. Several ITS services aim to minimize the risk of crash occurrence. This goal area focuses on reducing the number of crashes, and lessening the probability of a fatality should a crash occur. Typical measures of effectiveness used to quantify safety performance include the overall crash rate, fatality crash rate, and injury crash rate. Surrogate measures are also used, including vehicle speeds, speed variability, or changes in the number of violations of traffic safety laws.
Mobility
Improving mobility by reducing delay and travel time is a major goal of many ITS components. Measures of effectiveness typically used to evaluate mobility include the amount of delay time and the variability in travel time.
Delay can be measured in many different ways depending on the type of transportation system being analyzed. Delay of a system is typically measured in seconds or minutes of delay per vehicle. Also, delay for users of the system may be measured in person-hours. Delay for freight shipments could be measured in time past scheduled arrival time of the shipment. Delay can also be measured by observing the number of stops experienced by drivers before and after a project is deployed or implemented.
Travel time variability indicates the variability in overall travel time from an origin to a destination in the system, including any modal transfers or en-route stops. This measure of effectiveness can be readily applied to intermodal freight (goods) movement as well as personal travel. Reducing the variability of travel time improves the reliability of arrival time estimates that travelers or companies use to make planning and scheduling decisions. By improving operations, improving incident response, and providing information on delays, ITS services can reduce the variability of travel time in transportation networks. For example, traveler information products can be used in trip planning to help re-route commercial drivers around congested areas resulting in less variability in travel time.
Capacity/Throughput
Many ITS components seek to optimize the efficiency of existing facilities and use of rights-of-way so that mobility and commerce needs can be met while reducing the need to construct or expand facilities. This is accomplished by increasing the effective capacity of the transportation system. Effective capacity is the "maximum potential rate at which persons or vehicles may traverse a link, node, or network under a representative composite of roadway conditions," including "weather, incidents, and variation in traffic demand patterns." 43 Capacity, as defined by the Highway Capacity Manual, is the "maximum hourly rate at which persons or vehicles can reasonably be expected to traverse a given point or uniform section of a lane or roadway during a given time period under prevailing roadway, traffic, and control conditions." 44 The major difference between effective capacity and capacity is that capacity is generally measured under typical conditions for the facility, such as good weather and pavement conditions, with no incidents affecting the system, while effective capacity can vary depending upon these conditions and the use of management and operational strategies. Throughput is defined as the number of persons, goods, or vehicles traversing a roadway section or network per unit time. Increases in throughput are sometimes realizations of increases in effective capacity. Under certain conditions, it may reflect the maximum number of travelers that can be accommodated by a transportation system. Throughput is more easily measured than effective capacity and therefore can be used as a surrogate measure when analyzing the performance of an ITS project.
Customer Satisfaction
Given that many ITS projects and programs were specifically developed to serve the public, it is important to ensure that traveler expectations are being met or surpassed. Customer satisfaction measures characterize the difference between users' expectations and experiences in relation to a service or product. The central question in a customer satisfaction evaluation is, "Does the product deliver sufficient value (or benefits) in exchange for the customer's investment, whether the investment is measured in money or time?" Typical results reported in evaluating the impacts of customer satisfaction with a product or service include product awareness, expectations of product benefit(s), product use, response (decision-making or behavior change), realization of benefits, and assessment of value. Although satisfaction is difficult to measure directly, measures related to satisfaction can be observed, including amount of travel in various modes, mode choices, and the quality of service as well as the volume of complaints and/or compliments received by the service provider.
In addition to user or customer satisfaction, it is necessary to evaluate the satisfaction of the transportation system provider or manager. For example, many ITS projects are implemented to better coordinate between various stakeholders in the transportation arena. In such projects, it is important to measure the satisfaction of the transportation provider to ensure the best use of limited funding. One way to measure the performance of such a project is to survey transportation providers before and after a project has been implemented to see if coordination was improved. It may also be possible to bring together providers from each of the stakeholder groups to evaluate their satisfaction with the system before and after the implementation of an ITS project.
Productivity
ITS implementations can reduce operating costs and allow productivity improvements. Some applications may save time in completing business or regulatory processes, enabling businesses to increase their economic efficiency. For public agencies, ITS alternatives for transportation improvements may have lower acquisition costs and life cycle costs when compared to traditional transportation improvements. Other ITS applications enable the collection and synthesis of data that can translate into cost savings and performance improvements. Operational efficiencies and cost savings made possible by ITS implementation can help both public and private entities make the most productive use of their resources. The measure of effectiveness for this goal area is cost savings as a result of implementing ITS.
Energy and Environment
The air quality and energy impacts of ITS services are very important considerations, particularly for nonattainment areas. In most cases, environmental benefits can only be estimated by the use of analysis and simulation. The problems related to regional measurement include the small impact of individual projects and large numbers of exogenous variables including weather, contributions from non-mobile sources, air pollution drifting into an area from other regions, as well as the time-evolving nature of ozone pollution. Small-scale studies generally show positive impacts on the environment. These impacts result from smoother and more efficient flows in the transportation system. However, environmental impacts of travelers reacting to large-scale deployment in the long term are not well understood.
Decreases in emission levels and energy consumption have been identified as measures of effectiveness for this goal area. Specific measures of effectiveness for emission levels and fuel use include:
- Emission levels (kilograms or tons of pollutants including carbon monoxide (CO), oxides of nitrogen (NOx), hydrocarbons (HC), and volatile organic compounds)
- Fuel use (liters or gallons)
- Fuel economy (km/L or miles/gal)
1.4 REPORT ORGANIZATION
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This report follows a taxonomy for reporting ITS benefits and costs data. The ITS taxonomy used in this report groups benefits and costs data into two major components: Intelligent Infrastructure and Intelligent Vehicles. These components are then divided into program areas and specific ITS application areas. Figures 1.4.1 through 1.4.3 present an overview of this taxonomy. Subsequent sections of this report provide additional detail within each segment of the taxonomy. Intelligent Transportation Systems 
The taxonomy cannot represent all aspects of ITS. For example, many of the program areas can be dependent on or heavily influenced by other areas. This dependency is not well shown in the taxonomy. Also note that many ITS program areas share information and operate in a cooperative manner which is difficult to capture in this format. For example, traveler information systems, especially those regional or multimodal in nature, must rely on surveillance data collected by other ITS applications such as freeway, arterial, and transit management systems. In addition, in-vehicle driver assistance systems, such as navigation, can be augmented by a cooperative infrastructure to provide routing and/or travel time information to vehicle systems. Within this report, in cases of integrated deployment of more than one application, system cost and impact data appear under the program area that the implementation most directly supports. Sections 2 and 3 begin with a brief description of the ITS taxonomy components, Intelligent Infrastructure and Intelligent Vehicles, respectively. Subsequent subsections within these two sections include a brief description of each program area and specific ITS application area. The benefits and costs data are presented in tabular format based on the taxonomy structure for each program area. Within these tables, impact information is presented by goal area (e.g., safety, mobility, etc.) followed by a listing of relevant unit cost elements (refer to Appendix A) and concluding with available examples of system cost data. 
Figure 1.4.4 is an excerpt of Table 2.1.1 discussing the benefits and costs of arterial management systems; this portion presents the benefits and costs of adaptive signal control. Several pieces of information are provided in the benefits portion of the data table in each section of this report. The "Goal Area," one of the "Few Good Measures" discussed earlier in Section 1.3, is followed by the "Number of Studies" in the database identifying impacts within that goal area for a given application of ITS. The "Impact" rating in the third column represents an assessment of the application's impact on the performance goal area, considering the collection of reports in the database (a more complete discussion is provided in Table 1.0.1). Impact ratings fall into one of the six categories defined in the Impact Legend to the left, which is also repeated in each subsection within Sections 2 and 3 of this report. Example impacts for each application are included in the final column of the table, drawn from representative studies within the database. 
The costs portion of the data tables in each section includes a listing of relevant unit cost subsystems for the application. The icon to the left identifies applicable subsystems in the ITS Unit Costs Database for the given application area, which can be used to refer to unit cost information in Appendix A. The Unit Costs Database is regularly updated, with the most recent data available at www.benefitcost.its.dot.gov. 
Sample system cost information, along with a brief description of the implemented system, follows the unit cost information in each data table and is identified by the icon to the left. The purpose of presenting system cost information is to give the reader an example of systems that have been deployed along with the costs of each particular implementation. The reader is reminded that the costs represented are taken from the source documents and have not been adjusted to reflect 2003 dollars. The parenthetical date following the system cost information represents the year the cost data are based on, when known. A summary of the data presented in this report is provided in Section 4. A list of references and endnotes follows Section 4. Appendix A contains the ITS Unit Costs Database in table format, as of 30 September 2002. Appendix B contains a listing of acronyms used throughout the report. |
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2.0 BENEFITS AND COSTS OF THE INTELLIGENT INFRASTRUCTURE
The Intelligent Infrastructure consists of a wide variety of applications intended to improve the safety and mobility of the traveling public, while enabling organizations responsible for providing transportation facilities and services to do so more efficiently. Sections 2.1 to 2.13 of this report will discuss specific applications within the 13 program areas that make up the Intelligent Infrastructure listed in Figure 2.0. ITS can be deployed to improve the operation of freeways, arterials, and transit systems. Several applications can support critical transportation functions during emergency situations. Other applications facilitate convenient payment for highway tolls and transit fares. Traveler information programs synthesize information collected by ITS and disseminate it to travelers for their benefit in making travel decisions. Information management programs help transportation organizations manage and analyze the flow of data from deployed ITS and use it to improve transportation operations. Crash prevention and safety applications provide a variety of countermeasures, often location-specific, to address transportation safety concerns. Road weather management implementations improve the ability of the highway transportation system to react to adverse weather conditions. Several applications can improve the daily operation and continuing maintenance of the highway system. ITS for commercial vehicle operations (ITS/CVO) and intermodal freight applications help facilitate the smooth and safe flow of freight throughout the country and at our borders. Several metropolitan areas are implementing ITS services that are very highly integrated. Integration is accomplished by creating a number of interfaces or "links" between components, systems, services, or program areas. These links are used to share operational information and allow better use of infrastructure across jurisdictional boundaries. One example is sharing arterial traffic condition information originating from a traffic signal system with a freeway management system, allowing the freeway management system to provide expected travel times on alternate routes during congested periods. There are numerous other ways of integrating various implementations of ITS to achieve benefits greater than those of the individual system. The online Benefits Database contains a section presenting the evaluation reports that discuss integrated systems. For a more complete understanding of the integration of ITS components, consult the following documents:
These documents are electronically available on the FHWA electronic document library at www.its.dot.gov/itsweb/welcome.htm. The JPO-sponsored deployment tracking website, itsdeployment.ed.ornl.gov, contains updated information on ITS deployment in the United States. |
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2.1 ARTERIAL MANAGEMENT SYSTEMS
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Arterial management systems manage traffic along arterial roadways, employing traffic detectors, traffic signals, and various means of communicating information to travelers. These systems make use of information collected by traffic surveillance devices to smooth the flow of traffic along travel corridors. They also disseminate important information about travel conditions to travelers via technologies such as dynamic message signs (DMS) or highway advisory radio (HAR). 
Figure 2.1.1, showing a portion of the ITS taxonomy, lists the variety of systems that may be employed as part of arterial management systems. Many of the services possible through arterial management systems are enabled by traffic surveillance technologies, such as sensors or cameras monitoring traffic flow. Traffic signal control systems address a number of objectives, primarily improving traffic flow and safety. Transit signal priority systems can ease the travel of buses or light-rail vehicles traveling arterial corridors and improve on-time performance. Signal preemption for emergency vehicles enhances the safety of emergency responders, reducing the likelihood of crashes while improving response times. Adaptive signal control systems coordinate control of traffic signals across metropolitan areas, adjusting the lengths of signal phases based on prevailing traffic conditions. Advanced signal systems include coordinated signal operations across neighboring jurisdictions, as well as centralized control of traffic signals which may include some necessary technologies for the later development of adaptive signal control. Pedestrian detectors, specialized signal heads, and bicycle-actuated signals can improve the safety of all road users at signalized intersections. Arterial management systems with unique operating schemes can also smooth traffic flow during special events. A variety of techniques are available to manage the travel lanes available on arterial roadways, and ITS applications can support many of these strategies. Examples include dynamic posting of high-occupancy vehicle (HOV) restrictions and the use of reversible flow lanes allowing more lanes of travel in the peak direction of travel during rush hours. Parking management systems, most commonly deployed in urban centers or at modal transfer points such as airports, monitor the availability of parking and disseminate the information to drivers, reducing traveler frustration and congestion associated with searching for parking. Organizations operating ITS can share information collected by detectors associated with arterial management systems with road users through technologies within the arterial network, such as dynamic message signs or highway advisory radio. Arterial management systems may also include automated enforcement programs that increase compliance with speed limits, traffic signals, or other traffic control devices. Sharing information with other components of the ITS infrastructure can also have a positive impact on the operation of the transportation system. Examples include coordinating operations with a freeway management system, or providing arterial information to a traveler information system covering multiple roadway and public transit facilities.
For a summary of arterial management systems deployments across the U.S., refer to www.itsdeployment.its.dot.gov. Table 2.1.1 provides information on the benefits and costs of arterial management systems. Information provided on the impacts of these systems is indicated by using the symbols in the Impact Legend at the bottom corner of each page. |
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TABLE 2.1.1
BENEFITS AND COSTS OF ARTERIAL MANAGEMENT SYSTEMS
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