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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: Date: Summer 1994|
Issue No: Vol. 58 No. 1
Date: Summer 1994
This article is adapted from materials provided by the Federal Highway Administration's (FHWA) IVHS Program Management and Systems Engineering Division and from an article in the January 1994 IVHS Architecture Bulletin, published by IVHS AMERICA.
The Intelligent Vehicle Highway System (IVHS) is a large umbrella program that consists of a number of different user services in the categories of travel and traffic management, public transportation management, electronic payment, commercial vehicle operations, emergency management, and advanced vehicle safety systems. These services are related in that they all involve collecting, transmitting, processing, distributing, and displaying information. Moreover, the same information may be common to different user services and system components may be designed to accommodate requirements for multiple services.
The complexity and enormity of IVHS, its numerous and byzantine interconnections, and its far-reaching applications and implications all demand that it be put together from the start in a well-thought-out manner. This up-front planning will ensure that the deployment of IVHS user services will occur within the most sensible system framework. It will also ensure that a nationally compatible system emerges, instead of having local or regional pockets of IVHS that will not accommodate intercity travel or cross-country goods movement. For all of these reasons, IVHS needs a system architecture. In addition, Section 6053 (b) of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) requires the Secretary of Transportation to develop and implement standards and protocols that "... shall promote compatibility among intelligent vehicle-highway systems technologies implemented throughout the States."
American Association of Motor Vehicle Administrators
American Association of State Highway and Transportation Officials
American Association of Port Authorities
American Association of Retired Persons
American Automobile Association
American Automobile Manufacturers Association
American Bus Association
American Consulting Engineers Council
American Electronics Association
American Portland Cement Alliance
American Public Transit Association
American Public Works Association
American Road and Transportation Builders Association
American Trucking Association
Association of American Railroads
Council of Standards Organizations
Council of University Transportation Centers
Electronic Industries Association
Environmental Defense Fund
Human Factors and Ergonomics Society
Institute of Transportation Engineers
International Bridge, Tunnel, and Turnpike Authority
International Taxicab and Livery Association
National Association of County Officials
National Association of Governors' Highways Safety Representatives
National Association of Regional Councils
National Conference of State Legislatures
National Emergency Number Association
National Governors' Association
National Industrial Transportation League
National League of Cities
National Private Truck Council
National Safety Council
Public Technology, Incorporated
State and Territorial Air Pollution Program Administration/Association of Local Air
Pollution Control Officials
Surface Transportation Policy Project
Telecommunications Industry of America
U.S. Chamber of Commerce
A system architecture is the framework that describes how system components interact and work together to achieve total system goals and objectives. It describes the total system's operation, what each component of the system does, and what information is exchanged among the components. An architecture is neither hardware nor software. Rather, it is described on paper as charts and narrative--like a flowchart for a computer program.
The IVHS system architecture should be an open one. An open architecture allows for flexibility and innovation. It is functional so that hardware and software products from multiple vendors can be provided to meet system needs, thereby facilitating competition. It is modular to permit and facilitate the introduction of new technologies and system capabilities over time.
The development of an architecture is typically a top-down, systematic process. It involves an understanding of system goals and objectives, the functions and functional requirements a system has to meet to achieve these goals and objectives, and the different operational concepts and enabling technologies that can be used to build a system that satisfies the functional requirements. Furthermore, the system development involves rigorous analysis of the costs and impacts of different architectural approaches and broad consideration of the feasibility of implementing the system. The process also involves iteration, even to the point of evolving system goals and objectives and functions and functional requirements.
ISTEA requires the Department of Transportation (DOT) to provide the leadership and guidance necessary to ensure national IVHS compatibility over the long term. That compatibility relies upon establishing a unifying national IVHS architecture. It is vital that the architecture be designed in a systematic fashion so that all issues are addressed openly and directly, rather than having the architecture evolve in a ad hoc fashion.
The IVHS architecture development methodology uses efforts of concurrent multi-disciplinary public/private/academic teams. It requires contributors from many disciplines, including transportation analysts; systems engineers; and specialists in communications, information systems, infrastructure technologies, vehicle dynamics, data management, simulation, and modeling. Simulation and modeling are especially valuable for providing early indications of a user services cost/benefit ratio, and thus early indications of the desirability of continuing to pursue development of a particular service.
DOT has initiated the National IVHS Architecture Development Program to develop the needed IVHS architecture. The program will proceed in two phases. Based on proposals submitted in April 1993, DOT has selected consortia led by Hughes Aircraft, LORAL-IBM, Rockwell International, and Westinghouse Electric to each develop an alternative IVHS architecture. Phase I will last 15 months from September 1993 to December 1994 and will result in multiple architecture definitions. The consortia with the most promising architectures will continue into Phase II. Lasting 19 months from December 1994 to July 1996, Phase II will focus on detailed evaluation of the remaining alternatives. Throughout both phases, the consortia will have the opportunity to refine their architectures as they gain further knowledge and insight. At the conclusion of Phase II in mid-1996, a national IVHS architecture will emerge.
Management of the Architecture Development Program is vested in the DOT Architecture Team, comprised of representatives from DOT's FHWA, Federal Transit Administration, and National Highway Traffic Safety Administration. The Jet Propulsion Laboratory has been selected by DOT to serve as the Architecture Manager, providing day-to-day management oversight of the consortia.
A consensus building team, staffed jointly by DOT and IVHS AMERICA, will transmit information to and receive feedback from interests outside the technical development program. A team of private sector and academic technical expert--the Technical Review Team (TRT)--will review the technical soundness of the architecture alternatives submitted by the teams at certain program milestones.
On September 15, 1993, contracts were awarded to the four teams to independently define an IVHS architecture.
In January 1993, FHWA entered into an interagency agreement with National Aeronautics and Space Administration to obtain the services of the Jet Propulsion Laboratory to provide technical support in the management of the contract teams and to perform studies of technical issues that support the work of the teams.
The FHWA has formed an expert panel to review the competing IVHS architectural concepts under development. This panel, dubbed the IVHS Architecture Technical Review Team (TRT), is composed of 12 recognized experts in a wide range of specific technology and systems-oriented disciplines. Examples include communications technologies, benefits analysis, systems engineering and analysis, command and control, human factors, transportation systems, and other areas.
In the consensus area, a national task force has been formed by IVHS AMERICA. This group currently consists of about 40 organizations, including those that represent automobile and vehicle manufacturers, state and local government agencies, trucking interests, public transportation agencies, environmental groups, the electronic and communications industries, etc. The task force will be a primary source for providing feedback on the architectures in terms of perceived strengths and weaknesses.
In addition to the national task force, FHWA and IVHS AMERICA will host several sets of regional forums around the country, beginning on April 21,1994 in Atlanta, as the contract teams define and analyze their architectures. These briefings will help the teams respond to user needs in defining their architectures and also will help in the process of identifying the most acceptable architecture alternative. IVHS AMERICA technical committees will also be utilized as a means for providing feedback. In addition, focus group meetings will be sponsored on an as-needed basis to address issues that become important in the identification of the most acceptable architecture.
The development of an IVHS system architecture reduces risk to those responsible for providing IVHS infrastructure or investing in the development of IVHS products and services. For example, the development of an architecture will help resolve issues such as whether optimal routings are calculated by invehicle computers using information transmitted to the vehicle or calculated at traffic management centers and then transmitted to vehicles. This single issue has major implications on the costs of invehicle equipment (and, therefore, affordability), the costs of providing and maintaining public infrastructure, and which communications technologies can be accommodated.
The selection of an architecture will lead to development of system interface standards and protocols. These can be reflected in bid documents issued by public agencies responsible for deploying IVHS infrastructure and used by private firms involved in developing hardware and software products. As a result, deployment will be facilitated, national compatibility achieved, and competition--involving the best ideas and technologies that meet functional requirements--stimulated.
The IVHS system architecture effort will benefit from ongoing efforts and help to focus future efforts. Results from current research and development studies of technical, institutional, and legal issues and from operational tests will provide information on user service requirements, successful operational concepts, acceptable technologies, and cost and benefit data. This input will help shape the definition of alternative architectures.
Future program efforts will be focused according to the framework provided by the architecture. The range of possible user service operational concepts and enabling technologies will be narrowed by the selection of an architecture. The architecture will be especially helpful in guiding studies and tests involving multiple-user services, since these can be performed in the context provided by the architecture framework.
During the architecture development program, the key to success will be involving major stakeholders--those directly affected or influenced by the introduction of IVHS--in the decision-making process. Those who will use, design, build, operate, maintain, and be impacted by these systems must jointly decide upon a common system architecture. To involve these stakeholders, a consensus-building process has been initiated to gain cooperation among many classes of stakeholders in achieving the goal of a nationally compatible intelligent transportation system.
For IVHS, a consensus-building effort is essential. IVHS has many stakeholders with differing--often competing--interests. Since critical policy issues will be addressed by architecture alternatives, the consensus-building process will allow (and ensure) that stakeholders are aware of these policy issues and are able to provide meaningful feedback and input as it relates to these issues. The process is intended to help shape the resulting IVHS architecture to meet the needs of the stakeholders in a balanced fashion. Working with many other organizations, DOT and IVHS AMERICA will jointly manage the consensus-building process. Consensus-building activities will focus around the interim and final program reviews. These review "cycles" are scheduled for April-May 1994, October-December 1994, June-August 1995, and April-June 1996. At these points, the latest information on the developing alternatives, along with mechanisms to provide feedback, will be made available to the stakeholders through forums including:
Feedback from these forums will be used to refine the architecture alternatives. Feedback provided in the first two review cycles will also be factored into the process of selecting which teams continue on into Phase II. Feedback provided in the last two review cycles will help determine which of the remaining alternatives will be chosen as the national IVHS architecture. The consensus-building process will not seek to obtain total agreement by all stakeholders on all facets of the selected architecture. Rather, the aim is to develop general support within the broad stakeholder community behind the ultimate national architecture.
Each of the four contractor teams are, as of this writing, about halfway through the phase I effort to define an IVHS architecture. Their approaches are quite different in their visions of deployed systems and in the socio-economic implications of their architectures on the various stakeholders. The architecture teams are currently preparing to embark on the first round of consensus-building architecture forums. By the time this article is published, results from the first round of consensus building will have taken place. For the latest results on the architecture consensus efforts, contact IVHS AMERICA at (202) 484-4847 or FHWA at (202) 366-2196.
The Federal Highway Administration's (FHWA) Associate Administrator for Motor Carriers George L. Reagle tests his knowledge at a display featuring several sample questions that a truck driver must answer correctly to obtain a commercial driver's license.
Included in the Commercial Motor Vehicle Safety Act of 1986, the licensing program limits commercial drivers to just one license and requires that they pass specialized knowledge and skills tests. The license has been mandatory since April 1, 1992, and more than 6.6 million drivers now have one.
Test your knowledge. Included in the sampling of the questions on the traveling exhibit being examined by Mr. Reagle, who held top-level positions with the national transportation Safety Board and the National Highway Traffic Safety Administration before assuming his FHWA post last december, are:
(1) How far can you typically see at night with low beam headlights?
a. 30 meters (100 feet).
b. 76 m (250 ft).
c. 107 m (350 ft).
d. 152 m (500 ft).
(2) You are driving 88 km/h (55 mi/h) on dry pavement. How much distance will you need to stop your truck?
a. The length of the vehicle.
b. Twice the length of the vehicle.
c. Half the length of a football field.
d. The length of a football field.
(3) At highway speeds, if you are looking far ahead, you should be seeing about how far?
a. 2/5 kilometer (1/4 mile).
b. 4/5 km (1/2 mi).
c. 1/6 km (1/10 mi).
d. 1.1 km (2/3 mi).
(4) What is the required tread depth of the rear tires on a truck?
a. 8 millimeters (1/32 inch).
b. 16 mm (2/32 in).
c. 24 mm (3/32 in).
d. 32 mm (4/32 in). ANSWERS: (1) b; (2) d; (3) a; (4) b.