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• Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Literature Review

Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Literature Review

DISCUSSION

ATIS/CVO SYSTEM CONFIGURATIONS, FUNCTIONS, AND OBJECTIVES

DESCRIPTIONS OF CVO–SPECIFIC PROJECTS/SYSTEMS

ATIS/CVO HUMAN FACTORS EMPIRICAL EVALUATIONS

COMPARABLE SYSTEM EMPIRICAL FINDINGS APPLICABLE TO ATIS/CVO

THE IMPACT OF EMERGING TECHNOLOGIES ON ATIS/CVO SYSTEMS AND HUMAN FACTORS DESIGN CONSTRAINTS

ATIS/CVO SYSTEM CONFIGURATIONS, FUNCTIONS, AND OBJECTIVES

• Overview of ATIS Systems

• Description of U.S.–Based ATIS Projects/Systems

• Overview of ATIS Systems/Projects outside the United States

• European ATIS Projects/Systems

• Japanese Projects/Systems

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:

• Pathfinder provides drivers with navigation and real–time traffic congestion information.
• TravTek provides drivers with navigation, route guidance, real–time traffic congestion information, general traffic information, trip services, pre–trip planning, and emergency communication.
• AMTICS provides drivers with navigation, real–time traffic congestion information, trip services, and personal and emergency communication.
• RACS provides drivers with navigation, real–time traffic congestion information, trip services, and personal communication.
• AUTOGUIDE provides drivers with navigation and route guidance.
• ATLAS provides drivers with general traffic information and personal communication.
• CARMINAT provides drivers with navigation.
• CARIN provides drivers with navigation and trip services.
• HAR provides drivers with general traffic information and trip services.
• ARI and RDS provide drivers with general traffic information.

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:

• Route planning functions based on multiple criteria for route selection (e.g., fastest or fewest turns).
• Real–time display of traffic information and route replanning.
• "Yellow Pages" functions allowing selection of specific destinations based on several features (e.g., moderately priced Chinese restaurants within a given travel time).
• Emergency services functions (e.g., police, ambulance, towing).

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.

• Navigate More Effectively.

  The primary purpose of electronic automobile navigation assistance is to allow the driver to locate unknown destinations and assist in error–free planning and route following. In addition, systems will, in the near future, have the capability to provide detailed, relevant information about traffic, obstacles, and roadways. The driver will be able to navigate more effectively only if the system provides the information necessary for navigation in an accurate and timely manner.

• Navigate More Easily.

  Researchers have found that memorizing a route, either through lists or from maps, is difficult and not done well. Remembering spatial map configurations or mentally reorienting a map is also difficult for people and it conflicts with the spatial task of driving (Wetherell, 1979). Other navigation tasks are difficult because the information is not always available or is obscured (e.g., street signs). Therefore, providing drivers with an easy–to–use navigation system is a worthwhile design objective.

• Navigate and Drive Safely.

  Drivers should be able to navigate without jeopardizing driving performance. ATIS systems should be designed to minimize the demands imposed by the system and leave sufficient driver attention, information processing, and response resources for driving in all situations.

  In addition, information regarding upcoming obstacles or traffic congestion could warn drivers of potentially dangerous conditions. This feature could reduce risk, particularly in low visibility circumstances. Thus, with prudent design, navigation information systems could make driving safer and more secure.

• Optimize Roadway Use Efficiency.

  Since traffic congestion is a problem encountered by many drivers and is expected to get worse, some systems try to distribute traffic more evenly throughout a system using navigational assistance. If drivers are advised of congestion while planning their route, it is expected that they will avoid congested roadways. Thus, they would be able to avoid traffic congestion and not contribute further to the congestion problem. Also, if drivers are informed of obstacles or congestion that occur while they are en route, they may be willing to detour and avoid the congestion. The feasibility of this objective depends, in part, on the amount and detail of information provided to the driver while driving.

  While the majority of effort to date has been expended on IRANS development, the other ATIS subsystems, namely IMSIS, ISIS, and IVSAWS, hold promise for improving driving efficiency and safety. A paper by Green, Serafin, Williams, and Palke (1991) rated the relative costs and benefits of ATIS features. Based on ratings by four human factors ITS experts regarding the costs and benefits associated with accidents, traffic operations, and driver needs and wants, several IVSAWS features were found to be most desirable in future systems. Several in–car signing features were also highly ranked. In contrast, some IRANS features were ranked relatively low, primarily due to the potential safety cost of using such systems (Green, et al., 1991).

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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.

TravTek

"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.

• The majority of ATIS reports discuss TravTek. If the constructs involved in TravTek are understood, the constellation of in–vehicle navigation systems is roughly represented. Using the latest technology, the driver is aided in various navigation tasks, route selection, route guidance, local information, and system interface. Human factors design considerations have been used since the inception of the system. The driver accesses information through three vehicle modes: pre–drive (park), drive (vehicle in motion) and zero speed, which are both visual and auditory sensory channels. Extensive research into the needs and functions of both driver interface modalities was accomplished prior to the start of data collection. In addition, two visual display formats were available to the driver (Fleishman, Carpenter, Dingus, Szczublewski, Krage, and Means, 1991):

– 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).

ADVANCE

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.

Pathfinder

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:

• Voice messaging intelligibility was improved by digitizing common words and synthesizing less common ones. This also saved computer memory.
• Less critical information was filtered prior to being displayed (depending on the scale of the map) to avoid display clutter during peak traffic times.

Travelpilot

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.

DriverGuide

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.

FAST–TRAC

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.

ROGUE

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:

• Providing route planning expertise (e.g., tell how to get to the nearest florist, not just where the florist is located).
• Providing effective and efficient directions (i.e., information about the street network, road and traffic conditions, and points of interest).
• Providing navigation guidance during travel. This is an analog of a knowledgeable passenger.
• Detecting driving errors (i.e., wrong turns need to be detected and corrective guidances need to be provided).
• Operating without external equipment (i.e., high cost and dependence on communications signals can be avoided; the ability to use external data sources should be built in, if available).
• Maximizing driver comfort and safety (i.e., the system must not distract or degrade driving safety; simple spoken and graphic directions, along with automated driving–error detection, achieve this goal).

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.

CARIN

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."

SmartRoutes

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

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).

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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.

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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).

DRIVE

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:

• Demand management.
• Traffic and travel information.
• Integrated urban traffic management.
• Integrated interurban traffic management.
• Driver assistance and cooperative driving.
• Truck fleet management.
• Public transit management.

For detailed individual project descriptions, see Keen and Murphy (1992).

PROMETHEUS

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:

• Improved driver information – providing the driver with information from new sources of technology that were not previously available. Currently, the lack of information or the inability to assess a hazard is often the primary cause of accidents.
• Active driver support – when the driver fails in some way at the driving task, the system may aid the driver in an informative way or by active intervention.
• Cooperative driving – establishing a network of communication between vehicles in order to provide drivers with relevant information for areas en route to their destination.
• Traffic and fleet management – systems for the efficient use of the road network, ranging from highway flow control to fleet operations.

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:

• In–vehicle systems for vehicle monitoring and driver assistance.
• Vehicle–to–vehicle communications networks.
• Road–vehicle communications for traffic control.

The research subprograms cover the following:

• Development of required microelectronic components, including sensors and on–board computer systems by the PRO–CHIP researchers.
• Use of artificial intelligence in the vehicular system and software development by the PRO–ART research group.
• Communication within the system vehicle and driver, vehicle and vehicle, plus vehicle communications to the overall road network by the PRO–COM group.
• Vehicle change effects on the traffic environment will be studied by traffic engineers in the PRO–GEN group.

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:

• Vision enhancement.
• Emergency systems.
• Proper vehicle operation.
• Commercial fleet management.
• Collision avoidance.
• Test sites for traffic management.
• Cooperative driving.
• Dual–mode route guidance.
• Autonomous intelligent systems.
• Travel information systems.
• Cruise control.

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.

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Japanese Projects/Systems

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

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

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

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:

• Three available scales of map display: 1/25,000 (street grid by blocks), 1/100,000 (default arterial roads), and 1/400,000 (macro).
• The ability of the map heading to be toggled either "north up" or "direction of travel" at the top.
• Vehicle location, which is always positioned in the center of the scrolling map display.
• The reduction of eye glance time by not displaying minor roads while the vehicle is in motion. Also, while driving, the system inhibits all switch operation, except for "changing of scale" and "display rotation mode." It is not clear what the "display rotation mode" feature entails from the research described.

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FHWA-RD-95-153