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Human Factors Design Guidelines for Advanced Traveler Information Systems (ATIS)and Commercial Vehicle Operations (CVO)

CHAPTER 2: OVERVIEW OF THE ADVANCED TRAVELER INFORMATION SYSTEM (ATIS) SUBSYSTEMS AND FUNCTIONS

Components of the Intelligent Transportation System (ITS) are currently at various stages of research, development, and implementation. Numerous private firms are modifying products developed in Europe and Japan, or developing new systems to support their product development objectives. At the same time, the U.S. DOT is supporting research and development (R&D), system architecture development, operational tests, institutional and policy projects, and deployment projects through the national ITS program, as a means of stimulating the development of systems that will meet institutional and consumer objectives.

Two major areas of ITS development are ATIS and CVO. These types of systems will provide the primary means by which private and commercial vehicle drivers will interact with ITS. Thus, determination of the system characteristics that will enhance acceptance and usability of these systems is critical to the success of the ITS initiative. In recognition of this human factors challenge in developing ATIS and CVO systems, the Federal Highway Administration (FHWA) initiated the present project, which is being conducted to develop human factors guidelines for the design of ATIS and CVO systems. This project has addressed the impact of driver interfaces, information type, behavioral factors, and user demographics on the development of specific information subsystems.

Overview of Advanced Traveler Information Systems.

The above table summarizes the subsystems and functions associated with ATIS/CVO. More detailed summaries of each subsystem are provided by clicking below.

Capabilities of Routing and Navigation Functions

Capabilities of Motorist Services Functions

Capabilities of Safety/Warning Functions

Capabilities of Augmented Signage Information Functions

Capabilities Specific to CVO

Capabilities of Routing and Navigation Functions

Routing and Navigation Functions provide drivers with information about how to get from one place to another. When integrated with an Advanced Traffic Management System (ATMS), Routing and Navigation provides information on recurrent and nonrecurrent traffic congestion and is capable of calculating, selecting, and displaying optimum routes based on real–time traffic data. A sample of potential Routing and Navigation capabilities identified through interviews and a review of the literature is provided below. Basic capabilities of Routing and Navigation include:

• Providing drivers with route guidance information (how to get from one place to another).
• Providing drivers with navigation information (where they are in relation to their destination).
• Providing information on recurrent and nonrecurrent traffic congestion.
• Calculating, selecting, and displaying optimum routes based on real–time traffic data.

Some additional capabilities common among Routing and Navigation prototypes and emerging systems include:

• Turn–by–turn guidance (visual and voice displays).
• Notification of driver error.
• Recommended modifications inroute, due to traffic conditions or driver error.
• Selection of multiple–scale maps by the driver.

A number of variations of the basic capability to develop a route, including multiple destinations, have been cited in the literature. This capability has several applications for both private vehicles and CVO. Variations of this capability include:

• Planning a route for an extended vacation.
• Planning a route for a series of local deliveries.
• Planning a route for a business trip with several stops.

Several existing prototype and emerging Routing and Navigation technologies allow the driver to select from multiple criteria prior to the determination of a route to a destination. Some such criteria include fastest route, shortest route, route avoiding tollways, most scenic route, and route avoiding complex intersections.

Private industry representatives who have been involved in a recent Routing and Navigation technology development effort noted information that would be difficult to implement, but useful, including:

• Location of turn bays.
• Number of lanes.
• Exit numbers.
• Landmark information.
• Location of toll booths.
• Cost of tolls.

Return to Capabilities Section

Capabilities of Motorist Services Functions

Motorist Services Functions provide motorists with commercial logos and signing for motels, eating facilities, service stations, and other signing displayed inside the vehicle to direct motorists to recreational areas, historical sites, etc. Motorist Services Functions provide routing information for local destinations. A sample of specific Motorist Services capabilities identified through interviews and a review of the literature is provided below:

• Provides a source for a city's best hotels, restaurants, and just about all other vital services.
• Provides local routing information.
• Provides routing for any means of transportation––walking, driving, bus, train, and ferry.

Some have noted the value of having selection criteria available to aid the user in selecting restaurants, hotels, and other services. Restaurant selection criteria could include location, price range, type of food, and review rating. Hotel selection criteria could include location, price range, types of rooms, guest amenities, and review rating. A commonly discussed capability is that of being able to make reservations or purchases with a cellular phone link integrated with the Motorist Services device. Although Motorist Services Functions provide local routing information, closer integration with Routing and Navigation would provide additional capabilities by allowing selected services to be used as destinations in more sophisticated route guidance functions. Some means of integrating ATIS with public transit is desirable, and Motorist Services Functions provide an appropriate platform for this. Specific information that could be provided includes transit schedules, paratransit opportunities, costs, trip times, and dependable departure and arrival times.

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Capabilities of Safety/Warning Functions

Safety/Warning Functions provide warnings of unsafe conditions and situations affecting the driver on the roadway ahead. Safety/Warning Functions provide sufficient advance warning to permit the driver to take remedial action. Safety/Warning Functions provide messages related to relatively transient conditions, requiring modifications to the messages at irregular intervals. It should also be noted that mayday systems have been subsumed under Safety/Warning Functions for the purposes of the present discussion. Safety/Warning Functions do not encompass in–vehicle warnings of imminent danger requiring immediate action (e.g., collision avoidance devices). A sample of specific Safety/Warning Functions capabilities identified through interviews and a review of the literature is provided below. A basic capability of Safety/Warning Functions is that they are not limited simply to warnings of conditions. Advisory messages could also include recommended actions. It is important to note that Safety/Warning Functions, like Augmented Signage Information, could have the capability of transmitting multiple messages, with only a subset of messages appropriate for any class of vehicles. This has particular value to CVO, where truck–specific warnings could be provided for the following:

• Steep downgrades.
• Tight ramps and intersections.
• Railroad–grade crossings with limited sight distances.

Some have noted that Safety/Warning Functions could provide the capability of dynamic speed limits, which could facilitate trip smoothness (dynamic speed limits are currently used in Germany). Some law enforcement officials foresee the capability of Safety/Warning transmitters being installed on rolling hazards, such as emergency vehicles and school buses, providing an additional mode for warning signals. They also recognize the value of having portable transmitters available for their use in case of accidents. Several documents discuss the potential for automatic mayday systems that would be triggered by unusual events, such as a rollover or extreme deceleration of the type that would trigger airbags. The capability of linking a mayday system with a Global Positioning System (GPS) was identified as advantageous by many in the ITS community. Safety/Warning technology could be integrated with ATMS, or a more limited system of sensors and data processing capabilities, to provide dynamic messaging based upon prevailing conditions. One brochure for a prototype system extends the capability of a Safety/Warning device to provide real–time congestion information.

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Capabilities of Augmented Signage Information Functions

Augmented Signage Information Functions provide noncommercial routing, warning, regulatory, and advisory information that is currently depicted on external roadway signs inside the vehicle. Augmented Signage Information Functions are distinguished from Safety/Warning Functions on the basis of the relative permanence of the information displayed by this system. A sample of specific Augmented Signage capabilities identified through interviews and a review of the literature is provided below.

The basic capability of Augmented Signage Information is to warn drivers of conditions requiring their attention, prior to the conditions being easily determined by the driver without such a warning. Some have noted the potential capability of providing information specific to the characteristics of a particular vehicle. Such information could include:

• Curve speed for specific vehicle sizes.
• Braking requirements for specific grades.
• Routing restrictions for specific vehicle cargoes.

Augmented Signage Information Functions could respond to a limited set of queries by the driver to repeat messages that were not initially comprehended or attended to by the driver. Displays could be provided in a manner that could reduce the time spent by the driver looking away from the roadway. Augmented Signage Information Functions could provide more detailed instructions than are practical on roadway signs, and could display information reliably under adverse weather conditions. Augmented Signage Information displays could be optimized for use by elderly drivers, resulting in better information transfer than would be possible with external roadway signs. Specific capabilities would involve displays that could be better read at night and displays that avoid the problem of limited visual acuity.

Return to Capabilities Section

Capabilities Specific to CVO

CVO systems cover a broad spectrum of capabilities that have been identified to meet specific operational requirements. The scope of the present review has excluded crash avoidance systems, such as automatic clearance sensing. Following is a sample of CVO–specific system capabilities identified through interviews and a review of the literature.

Much of the technology being proposed for CVO–specific system development is currently available and implemented in limited degrees. This has allowed the transportation community an opportunity to become quite familiar with alternative capabilities. It has also resulted in a well–developed set of descriptions for these capabilities in the Strategic Plan for Intelligent Vehicle–Highway Systems in the United States (Intelligent Vehicle Highway Society of America, 1992). Because of the excellent, comprehensive nature of the strategic plan, it serves as the primary reference in the following discussion. Specific capabilities identified and described in that report are excerpted below:

• Electronic Credentials (EC) – would enable a motor carrier to electronically file for, obtain, and pay for all required licenses, registrations, and permits. An electronic record of the credential could be sent to the motor carrier's headquarters or other desired location.

• Hazardous Material Information Systems – could provide enforcement and incident management response teams with timely, accurate information on cargo contents, enabling them to react properly in emergency situations.

• Automatic Vehicle Classification (AVC) – employs EC technology to provide a readable, electronic record of vehicle type and contents.

• Automated Vehicle Location (AVL) – employs GPS, or other triangulation technologies, to provide real–time information regarding the location and status of vehicles.

• Driver/Vehicle Real–time Safety Monitoring – could include records of duty logs, medical qualifications data, and commercial driver's license information. Vehicle–related elements could include operational data and conditional information, such as status of brakes, lights, tires, and steering.

• Electronic Log Book – could replace the manual trip log typically prepared by the motor carrier. The fuel tax rates for each state and the number of vehicle–miles traveled within each state could be recorded electronically if electronic beacons were provided at all site boundaries.

• Automated Vehicle Classification/Identification (AVC/AVI) – would allow uninterrupted movement of the vehicle through inspection or weighing stations.

• Weigh in Motion (WIM) – allows motor carriers equipped with special transponders to proceed on the highway at normal speeds through instrumented weigh stations as their weight is electronically inspected by in–pavement scales and readers.

• Automated (Electronic) Toll Collection – would apply the same technologies as those used in automated credential checking.

• Two–Way Real–Time Communications (TWC) – would provide ATIS and ATMS information concerning congestion, incidents, and optimum routing to drivers or dispatchers.

• Advanced Fleet Management – uses advanced vehicle routing algorithms that collect real–time congestion information to balance routes and loads, and predict travel times.

FHWA-RD-98-057