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Federal Highway Administration Research and Technology
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Publication Number: FHWA-RD-95-153
Date: November 1996
Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Literature Review
ATIS/CVO SYSTEM CONFIGURATIONS, FUNCTIONS, AND OBJECTIVES
Overview of ATIS Systems
According to Perez and Mast (1992), the major goal of ATIS is to improve the information that is provided to travelers. This includes information for traveling in normal and poor weather, congested, and emergency conditions. In the early stages of ATIS development, the emphasis is primarily on providing travelers with information to improve their planning and decision making. In the later stages of ATIS development, the emphasis will be on supplementing static on–board information with dynamic traffic information that is collected and transmitted from other segments of the ITS to optimize individual travel time.
During our literature search, several papers were found that define major concepts and problems of ATIS systems (Rillings and Betsold, 1991; Haselkorn, 1992; Ratcliff and Behnke, 1991; Rothberg, 1990; Rutherford and Mahoney, 1989; Mast, 1991; Hancock and Caird, 1992). Rillings and Betsold (1991) discuss a 20–year plan for the evolution of ADIS developed at a series of workshops sponsored by Mobility 2000 (1990, 1991). The evolution of these systems is anticipated to progress through three stages:
1990 to 1995: This stage will focus on providing each driver with information to improve individual planning and decision making. Most of these systems will rely on the vehicle's own resources, such as dead reckoning, on–board data bases, and static route selection.
1995 to 2000: This stage will focus on supplementing the static information of the information stage with data obtained from the infrastructure. The vehicle information systems will advise the driver of the correct routes and guide the driver step by step over those routes.
2000 to 2010: This stage will focus on automatic exchange of information between the infrastructure and vehicles. Vehicles will be used to report traffic conditions and the infrastructure will combine the data from these reports and use it to control traffic signals and inform drivers of alternate routes.
Rillings and Betsold (1991) suggest that a major goal of the near–term advisory stage of ITS is to provide automatic minimum travel–time route selection and guidance using up–to–the–minute traffic information. During the middle–term coordination stage, the vehicle equipment and the infrastructure should also support an automatic mayday feature.
To accomplish the overall ATIS goal, there have been several classes of systems identified within the ATIS program: In–vehicle Routing and Navigational Systems (IRANS), In–vehicle Motorist Services Information Systems (IMSIS), In–vehicle Signing Information Systems (ISIS), and In–vehicle Safety Advisory and Warning Systems (IVSAWS) (Perez and Mast, 1992). Thus far in the evolution of ATIS, the vast majority of developed systems and empirical research has centered around IRANS applications. IMSIS functions are empirically represented in a few instances, and ISIS and IVSAWS are greatly under represented in early system development. A summary of the functions of recent ATIS projects provided by Rillings and Betsold (1991) illustrates the emphasis on IRANS to date. These projects include Pathfinder, TravTek, Advanced Mobile Information and Communication System (AMTICS), RACS, AUTOGUIDE, Acquisition par Télédiffusion de Logiciels Automobiles pour les Services (ATLAS), CARMINAT, Car Information and Communication System (CARIN), Media Intelligent pour l'Environnement Routier du Véhicule Européen (Minerve), Highway Assistance Readout (HAR), Army Research Institute (ARI), and Radio Data System (RDS). The basis functionality of the systems associated with each of these projects is summarized below:
These systems (and others) are described in greater detail in the following sections.
As illustrated above, existing IRANS systems and conceptual designs vary greatly with respect to functionality, driver information, and design. In fact, some systems (e.g., TravTek) incorporate IRANS and IMSIS functions into a single device. Although no determination has been made regarding available functions on most systems under development (Lunenfeld, 1990), a number of features will likely be useful and integrated as part of future systems. These features include the following:
The number of potential benefits and the perceived marketability of IRANS is a major reason for the development activity centered around IRANS applications. Navigation to an unknown destination without passenger assistance is a difficult task and, in most cases, is performed inefficiently or unsuccessfully. Outram and Thompson (1977) and Jeffery (1981) estimate that between 6 percent to 15 percent of all highway mileage is wasted due to inadequate navigation techniques. This results in a monetary loss of at least $45 billion per year (King, 1986).
A traffic delay can also be potentially reduced by widespread use of navigation systems. Several systems under development are designed to interface with advanced traffic management centers that will eventually be based in metropolitan areas. Once such systems are in place, real–time traffic delays can be broadcast to in–vehicle systems. These systems can then be used to continuously calculate the fastest route to a destination during travel. That capability, if widely used, could increase efficiency for an entire infrastructure network.
Given the level of development effort and the benefits of navigation systems, widespread development will continue. Thus, it will be critical that systems are required to be designed with human factors objectives to ensure system safety, efficiency, and usability. Dingus and Hulse (1993) specify human factors–related objectives for such systems. These objectives are listed below.
Description of U.S.–Based ATIS Projects/Systems
Most available reports of U.S.–based ATIS systems and projects are of a descriptive nature. With the exception of TravTek and Pathfinder, field or laboratory evaluations were lacking. Pathfinder was of limited scope (25 cars) and was the first domestic ITS project. Its main purpose was to demonstrate the feasibility of ITS and promote further study. The TravTek operational testing phase was completed in March 1993. By the third quarter of 1993, significant information on TravTek should be available from Orlando testing. Therefore, the data that are currently available to support the development of human factors guidelines are limited, but will continually improve for the duration of this project.
A description of each of the planned or completed U.S. ATIS projects is presented below.
"Travel Technology," a demonstration system developed by General Motors (GM) that involved the City of Orlando, the Florida Department of Transportation (DOT), the Federal Highway Administration (FHWA), and the American Automobile Association (AAA), is nearing completion. The TravTek system was a complete ITS infrastructure, including a Traffic Management Center (TMC), traffic monitoring and sensing, and route guidance information. The goal of TravTek was to reduce congestion and provide information on geographic attractions and services. The TravTek interface linked drivers of 100 test vehicles to real–time information via digital data broadcasts. Avis rental car customers and solicited subjects participated in the testing.
– A turn–by–turn graphic "guidance screen."
– A color route map.
Several reports and publications are available describing the system. For system architecture, see the report by Rillings and Lewis (1991). Information on task analysis is in a paper by Krage (1991). Human factors design aspects are described by Fleishman, et al. (1991) and Carpenter, Fleishman, Dingus, Szczublewski, Krage, and Means (1991). Finally, the design of the auditory interface is described in Means, Carpenter, Fleishman, Dingus, Krage, and Szczublewski (1992).
The largest operational test of ITS will be based in Chicago and its northwestern suburbs. The Advanced Driver and Vehicle Advisory Navigation Concept (ADVANCE) brings together the efforts of major ITS manufacturers Ford, Toyota, Nissan, Saab, Volvo, Peugeot, ETAK, Navigation Technologies, DonTech, Motorola, and Sun Microsystems. Institutions in Illinois are also involved, including Illinois Universities Transportation Research Consortium, City of Chicago, and the Illinois DOT.
This project is still in the planning stage, but is nearing operation. The ADVANCE operational test is very similar to TravTek, but it also focuses on reducing congestion on arterial roadways, as well as on highways.
As the first in–vehicle navigation system project in the United States, Pathfinder involved Caltrans, GM, and FHWA. This project focused on a 20.9–km (13–mi) stretch of the Santa Monica Freeway, where 25 vehicles were equipped with ETAK–modified displays. Information on accidents, congestion, highway construction, and route diversion was presented to the driver, either on the map display or through digital voice. The final phase of evaluation took place in spring 1992.
Pathfinder is one of the few projects with a publication describing human factors aspects of system design. Mammano and Sumner (1989) make the following design observations:
Travelpilot, a joint project of Bosch and ETAK, is an after–market navigation system. This device forms the core of the Pathfinder system and is also used in over 400 emergency vehicles in Los Angeles. The system consists of wheel sensors, compass, microcomputer with Compact Disc–Read–Only Memory (CD–ROM) map data base, and an 11.4–mm (4.5–in) vector–drawn monochrome display. In addition, Travelpilot can be linked to communication systems for real–time data display.
Pre–trip out–of–vehicle route guidance is conducted using this system. Users enter origin–destination pairs and receive a printed set of instructions. The system was tested on French air travelers visiting San Francisco.
The Ali–Scout system, developed as a joint project of the Federal Republic of Germany, Siemens, Volkswagen, Blaupunkt, and others, is used as part of the FAST–TRAC project in Oakland County, Michigan. The display is a simple Liquid Crystal Display (LCD) readout that shows driving instructions with arrows at appropriate intersections. Infrared communication occurs at beacons located at key intersections to update the vehicle information systems. FAST–TRAC is relatively low cost on a per vehicle basis, but requires intersections to be equipped with transmitting beacons.
Navigation Technologies Corp. has developed the route guidance expert system, ROGUE, for daily in–vehicle navigation. The ROGUE software draws on the NavTech digital street map data bases. Embedded in the CD–ROM data base is information that simulates human intuition about routing, such as time of day (e.g., rush hour). The system can run on a stand–alone basis or with an infrastructure updating its information. The stand–alone option is used as a selling point since the global positioning system (GPS) and communication infrastructures can be cost–prohibitive. Points of interest are also coded into the data base. ROGUE uses an in–dash cathode ray tube (CRT) display.
The expert system for the ROGUE in–vehicle route guidance is described in a report by Silverman (1988). There are six design concepts specified in the report. These concepts are:
The driver interface is also described in the Silverman report. A video display terminal (VDT) mounted in the instrument cluster delivers requested navigation information. The display is monochrome, but provides line graphics as well as text capability. Also, a speech synthesis unit aurally provides directions. The driver can toggle the system to give spoken directions or chime when directions are updated on the screen, beckoning the driver to glance at them. Driver input is provided via an alphanumeric keyboard.
Philips Corporation's CAR Information and Navigation (CARIN) system is an early implementation of the Compact Disc–Interactive (CD–I) format of storing digital maps (Thoone, Dreissen, Hermus, and van der Valk, 1987). Vehicle location is accomplished by dead reckoning and map matching. Included in the system design is a radio data link for traffic information. The driver is guided with synthesized speech in conjunction with a pictogram display (similar to the Ali–Scout).
The system requires a keyboard for driver input, while a supplemental color touch screen is optional. A flat–panel display is used in the basic configuration, which shows stylized map graphics to supplement the audio. Maps are presented "heading up."
Liebesny (1992) discusses the SmartRoutes system that will service the Boston metropolitan area. The system will use real–time data from a traffic information center. Drivers will be able to access this information through the use of a land line, cellular phone, cable television, direct fax, or computer modem. Various automated mechanisms, such as interactive audiotext and video graphics, have been developed to disseminate the information. Liebesny (1992) recommends that the information be kept current and the system design updated continuously with a maximum acceptable aging period of 15 min. He also suggests developing a coordinated public/private partnership to handle the full aspects of incident management.
TRIPS includes dispatching of single–trip carpooling or parataxi systems, enabling drivers and riders to use touch–tone telephones, personal computers, and videotext terminals to obtain information on local traffic information and alternative route information (Ratcliff and Behnke, 1991).
Overview of ATIS Systems/Projects Outside the United States
Other countries are more advanced in ITS technology than the United States due, in part, to their traffic congestion. The traffic congestion in Europe, and especially Japan, is considerably worse than in this country. However, the United States should follow the rest of the world's example and implement a structured system of traffic management before its problems get worse. The systems in other countries were all formed as joint operations between government, industry, and research institutions. Without this collaborative effort, projects of this magnitude would have had little chance of success.
The reason for combining the operations of government, industry, and research institutions was to get a global perspective on current problems and solutions. In this way, resources could be put to use on citywide or country operational systems. This scale of organization has not been adopted in the United States. In addition to traffic flow and route navigation information, developments from other countries include driving aides such as collision avoidance and driving condition monitors. Human factors guidelines can be drawn by the study of these programs, their individual systems, and their direct research findings.
European ATIS Projects/Systems
Europe has several large–scale programs in progress under the umbrella of Road Transport Informantics (RTI), which is the equivalent of the U.S. ITS. Their main programs are dedicated road infrastructures for vehicle safety in Europe (DRIVE) and the program for European traffic with highest efficiency and unprecedented safety (PROMETHEUS). These two programs are separated by the organizations that formed them, but their goals are largely the same. DRIVE is under the control of the Commission of European Communities (CEC), while PROMETHEUS is part of the European Research Coordination Agency (EUREKA) platform, an industrial research initiative involving 19 countries and European vehicle manufacturers. While the projects are separate, close cooperation between the two is needed to reach a common goal. Actual system development is the primary goal of the PROMETHEUS project, while DRIVE tends to focus on human behavior issues and implementation of systems into the entire European community. Detailed program material can be found in: McQueen and Catling (1991), Kemeny (1990), Hellaker (1990), and Transport Canada (1992).
The intention of DRIVE is to move Europe towards an Integrated Road Transport Environment (IRTE) by improving traffic efficiency and safety and reducing the adverse environmental effects of the motor vehicle. It focuses on the infrastructure requirements, traffic operations, and technologies of interest to public agencies responsible for the European road transport systems. DRIVE also focuses on the human user and related issues that will be addressed in the implementation of in–vehicle systems.
DRIVE I was the first phase of the project and was started in 1989. It was funded for 3 years with an operating budget of $150 million. The pre–competitive research program consisted of 60 individual projects undertaken by members from the private sector, government agencies, and research institutions. The goal was to establish the overall work plan from which a European IRTE could be developed. The program has been highly successful and is now moving on to the demonstration phase.
The DRIVE program was seen only as a feasibility study in the beginning. However, as DRIVE progressed, it became apparent that there was a realistic opportunity for system development. This resulted in DRIVE II, which emphasized the implementation of pilot projects that had been developed as a result of DRIVE I. Funding was increased to about $250 million in order to construct and test hardware. DRIVE II is scheduled to end in 1995, and the release of products into the marketplace is expected at that time. The DRIVE II work plan identifies seven pilot project areas:
For detailed individual project descriptions, see Keen and Murphy (1992).
PROMETHEUS was started in 1986 and was initiated as part of the EUREKA program, a pan–European initiative aimed at improving the competitive strength of Europe by stimulating development in such areas as information technology, telecommunications, robotics, and transport technology. The project is led by 18 European automobile companies, state authorities, and over 40 research institutions. The budget for the project is over $800 million and the project is scheduled to last 7 years. PROMETHEUS is a pre–competitive research project, with the output being a common technological platform to be used by the participating companies once the product development phase begins. The overall goals of PROMETHEUS fall into four categories:
The emphasis of PROMETHEUS, however, is on systems having a large in–vehicle component to their design. The ultimate aim is for every vehicle to have an on–board computer to monitor vehicle operation, provide the driver with information, and assist with the actual driving task. A centralized communications network will also be a component of the system in order to provide two–way communication between each vehicle and a control center.
Within the PROMETHEUS program, there are seven subprograms; three are carried out by the motor industry, and four are carried out by the research community.
The industry subprograms cover the following:
The research subprograms cover the following:
The research phase, covering the past 4 years, has largely been completed. The current move is toward the definition phase, where the emphasis has shifted to field tests and demonstrations. Ten common European demonstrations have been identified to evaluate systems in each of the following areas:
These demonstrations are scheduled to be completed by 1994; however, it is likely that PROMETHEUS will continue beyond that date. The second phase will be somewhat modified to reflect the near–market status of products under development, and will move away from the program's non–competitive origins.
In order to bring products to market more quickly in Europe, European Road Transport Telematics Implementation Coordination Organization (ERTICO) was created in November 1991. Its objectives are to pool the information from the many individual projects and identify strategies in order to exploit the results of DRIVE, PROMETHEUS, and other individual programs. ERTICO's goal is to create a climate for market–driven investment in order to ensure European dominance in advanced–vehicle technologies.
Individual system descriptions
Many individual RTI/ITS systems are now being tested throughout Europe. A short description of some individual systems is presented below to enhance the reader's understanding of developments taking place in Europe. System descriptions will be limited to the driver interface, as opposed to actual system hardware and communications network information.
Autoguide and the Ali–Scout are dynamic in–vehicle route guidance systems; that is, the system gives routing recommendations to drivers who are dependent upon real–time traffic conditions. The display unit is mounted on the dashboard of the car and controlled with a hand–held remote control (similar to a television remote). At the start of a journey, the driver can enter a grid reference or a preprogrammed destination. The system uses dead reckoning and roadside infrared–transmitter/receiver beacons to guide the driver to the selected destination. The beacons serve the system by correcting cumulative errors and updating traffic information. The navigation information presents directions to the driver through the use of icons and arrows. There is also a digitized speech unit that supplements visual directions. The Autoguide system has undergone extensive testing in London, while the Ali–Scout system has over 700 units being tested in Berlin. For more information, refer to one of the following articles: Catling and Belcher (1989), Jeffery, Russam, and Robertson (1987), Jurgen (1991), or Morans, Kamal, and Okamoto (1991).
TrafficMaster from the United Kingdom (U.K.) was the first commercially available in–vehicle system to provide dynamic traffic information to the driver. It is a map–based system that only provides traffic flow information; it does not actively suggest routes. The display screen is a 101–mm by 82–mm (3.9–in by 3.2–in) in–liquid crystal display that provides the map information. "Hard" push buttons for control of guidance functions are mounted next to the display (Jurgen, 1991).
TRAVELPILOT is a German autonomous navigation system based on the American ETAK Navigator sold by Blaupunkt Bosch Telecom. This system displays vehicle location on a dashboard–mounted CRT map that is stored on CD–ROM. The maps move relative to the vehicle's position, which is determined through the use of dead reckoning and map matching. A small CRT can display maps with highlighted routes or driving instructions that have intersection maps and street names. Hard buttons mounted on either side of the CRT are changeable function controls. The system has reportedly sold over 1000 units in its first year on the market and will be available soon in the United States for certain areas. For more information, refer to the following references: Suchowerskyj (1990), and Morans, Kamal, and Okamoto (1991).
Many other individual systems already exist or are in the prototype testing phase. Systems on the market currently tend to be navigation systems, but other driver information systems, such as collision warning systems, are nearing completion. These will most likely be marketed by the automobile manufactures and not by after–market suppliers.
Japan is leading all other countries in the implementation of a large–scale traffic control system that uses in–vehicle technology. The reason for their lead is due to their need for such systems. Over vast portions of metropolitan areas in Japan, the average speed is below 16.1 km/h (10 mi/h) during much of the daytime hours. The small geographic area and large population has led the Japanese government to install traffic control systems in all the large cities and on most urban and interurban freeways. These systems employ the latest technology, such as fiber–optic communications and in–color light–emitting diode (LED) changeable message signs displaying both text and graphics. Japan has invested in the development of driver information systems. Over 50 corporations have collaborated to develop in–vehicle systems that are marketed as units to be purchased by individuals who use the governmental road network system. The main ITS initiatives currently are road/automobile communication system (RACS), advanced mobile traffic information and communications system (AMTICS), and vehicle information and control system (VICS). Within RACS, the Ministry of Construction (MC) promoted and funded the Digital Road Map Association. This group was given the task of preparing and maintaining a national digitized road map data base. The results of this work are available on compact disc in a standard format. This format is used by both RACS and AMTICS, as well as by the various manufacturers of autonomous vehicle navigation systems (Ervin, 1991).
RACS is sponsored by the Public Work Research Institute of the MC, the Highway Industry Development Organization (HIDO), and 25 private companies. The system consists of vehicles equipped with dead reckoning navigation systems, roadside communication units (beacons) that are distributed throughout the road network (about 2 km (1.24 mi) apart), and a control center. There are three types of roadside beacons: Type 1 transmits location to the vehicle to zero–out cumulative navigation errors; Type 2 transmits, in addition to location, congestion and other traffic information; and Type 3 provides two–way communications with the vehicle so that information about the vehicle (e.g., location, automatic debiting of tolls, etc.), as well as emergency calls, can be transmitted to the control center. The MC recently announced a major beacon installation program, consisting mostly of Type 1. At present, there are about 1,000 beacons around Tokyo. Beacon installation is scheduled to proceed throughout Japan at a rate of about 10,000 beacons per year until 1994, with a gradual increase in the number of Type 2 and Type 3 beacons. Travel–time savings of 3 to 5 percent are expected, representing a significant reduction in fuel consumption and air pollution.
AMTICS is sponsored by the National Police Agency (NPA), the Ministry of Posts and Telecommunications (MPT), the Japan Traffic Management and Technology Association (JSK), and 59 private companies. It employs in–vehicle equipment similar to that of RACS, with the exception of the communication interface. The AMTICS data link is essentially a one–way means of broadcasting traffic data from a cellular system of terminals. It is intended to convey a wide variety of information, including congestion information, travel–time predictions, traffic regulations, railway timetables, and special events advice. This information is available at static terminals at railway stations, hotel lobbies, etc., as well as in the vehicle. A large–scale test of AMTICS was held in Osaka in 1990, and the results suggest that an individual travel–time reduction of about 7 percent could be achieved with in–vehicle navigation systems that provide congestion information to the driver. This would amount to individual travel–time savings of about $300 million if all cars were equipped in the Osaka area, with similar savings to the community because of reduced congestion. For more information on the AMTICS system, see papers by Okamoto (1988), Okamoto and Nakahara (1988), or Okamoto and Hase (1990).
VICS is a new program formed under the combined direction of the MPT, MC, and NPA, with the goals of resolving the competition between RACS and AMTICS and defining a common system using the best features of both. This venture is meeting with some opposition by those who feel that the competition between the two systems is improving both. A digital micro cellular radio system has been proposed to provide two–way road–vehicle communications and location information, essentially combining the tools used by each respective system. Although VICS may have a long–term future as part of an integrated driver information system for Japan, it will take some years to implement. In the meantime, a common RACS–AMTICS system using RACS Type 1 beacons and the broadcast of information to drivers via their FM car radios (like Radio Data System–Traffic Message Channel (RDS–TMC)) is the likely direction for further development.
Until now, traffic condition information was fed to drivers over the radio or through a supplemental system such as those mentioned above. However, most Japanese prefer to plan their own navigation routes rather than blindly follow directional arrows on an in–vehicle display (as is the case for the Autoguide systems used in the U.K.). The trend of opposition to blind direction following was researched by Schraagen (1990). The effect of "planning" routes while the vehicle is in motion on road safety has not yet been investigated in depth by the Japanese. This lack of investigation seems to be a trend in the development of Japanese systems.
Japanese systems tend to be put on the market with displays that are very detailed simply because the technology exists to do so. The litigation system in Japan gives some leniency for this type of system development and even for unsafe designs.
A Nissan system
A digital map–based system is sold with the Nissan Cedric, Gloria, and Cima models in Japan. It is similar in design to the ROGUE and TRAVELPILOT discussed in the previous section. A paper by Tanaka, Hirano, Nobuta, Itoh, and Tsunoda (1990) describes some of the interface aspects of this system. These aspects include: