NAVIGATION AIDS AND IVHS
`
`29.7
`
`
`
`FIGURE 29.3 Nodes and street segments of vector encoded map.
`
`By considering each road or street as a series of straight lines and each intersection as a node,
`a map may be viewed as a set of interrelated nodes, lines, and enclosed areas as illustrated by
`Fig. 29.3.
`Nodes may be identified by their coordinates (e.g., latitude and longitude). Additional
`nodes “shape points” are positioned along curves where the link between two intersections is
`not a straight line. Curves are thus approximated by a series of vectors connecting shape
`points, whereas a single vector directly connects the node points representing successive inter—
`sections if there are no curves in the connecting road segment.
`The X-Y coordinates of node points may be encoded from maps or aerial photographs.
`The classic approach uses special work stations which record the coordinates of a given point
`when the cross hair of an instrument is placed over the point and a button pressed. This pro-
`cess has been automated in varying degrees. In some cases, the printed map is scanned to
`obtain a matrix image, which is then converted to vector form by software.
`Various combinations of attributes associated with the encoded road network are included
`in digital map databases. Of particular importance are roadway classifications, street names,
`and address ranges between nodes. Map databases used with systems that give turn-by-turn
`route guidance also require traffic attributes such as turn restrictions by time of day and
`delineation of one—way streets. Directory and yellow pages information for selecting attrac-
`tions? parking, restaurants, hotels, emergency facilities, etc, are commonly included.
`
`29.2.4 Map Matching
`
`Map matching is a type of artificial intelligence process used in virtually all Vehicle navigation
`and route guidance systems that recognize a vehicle’s location by matching the pattern of its
`apparent path (as approximated by dead reckoning and/0r radiopositioning) with the road
`patterns of digital maps stored in computer memory. Most map—matching software may be
`classified as either semideterministic or probabilistic.4
`
`641
`641
`
`

`

`29.8
`
`EMERGING TECHNOLOGIES
`
`Semideterministic. This approach assumes that the equipped vehicle is essentially confined
`to a defined route or road network, and is designed to determine where the vehicle is along a
`route or within the road network. The concept may be illustrated by tracking the location of a
`vehicle over the simple route shown in Fig. 29.4a which defines a route from node A through
`nodes B, C, D, E and thence back to A in terms of instantaneous direction ((1)) of travel versus
`cumulative distance (L) from the beginning as shown in Fig. 29.4b. Locations of nodes where
`direction changes occur (or could occur) are thus defined in terms of distance L. The solid line
`gives heading versus distance corresponding to the simple route. Alternative routes emanat—
`ing from each node are indicated by dashed lines.
`
`
`
`FIGURE 29.4 Simplified route and vector model.4
`
`Figure 29.5 shows the kernel of a semideterministic algorithm in highly simplified form.
`Once initialized at a starting location (¢ = 90° and L = 0 at Node A in the example), the algo-
`rithm, in effect, repeatedly asks, “Is the vehicle still on the route?” and “What is the present
`location along the route?” The vehicle is confirmed on the route if certain tests are satisfied.
`The location along the route is estimated by odometry, and error in the estimate is automati—
`cally removed at each node where it is determined that an expected change in heading actu—
`ally occurs.
`
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`

`NAVIGATION AIDS AND WHS
`
`29.9
`
`
`RIGHT
`LEFT
`
`WHEEL
`WHEEL
`
`INTERRUPT
`INTERRUPT
`
`
`EXIT T0
`
`ERROR
`ROUTINE
`
`
`
`EXIT T0
`ERROR
`ROUTINE
`
`
`
`
`
`
`TURN
`it
`
`
`
`WITHIN
`MIDPOINT
`
`
`LIMIT
`
`
`
`
`SET L To
`HIDPOINT
`
`
`IN ITIAL I 33
`NEXT
`VECTOR
`
`
`
`
`RETURN TO PRIOR ROUTINE
`
`FIGURE 29.5 Simplified map—matching algorithm.‘
`
`The Inap~matching algorithm is driven by interrupts from differential odometer sensors
`installed on left and right wheels. The distance L from the beginning of a route segment is
`updated by adding an increment AL for each left wheel interrupt, and the vehicle heading at} is
`updated by adding an increment 23¢ calculated from the difference in travel by the left and
`right wheels since the count N was last set to 0. As explained below, the N counter controls
`monitoring for unexpected heading changes Occurring over relatively short distances.
`Unless the turn flag is set to denote that the vehicle is approaching a distance L where a
`heading change should occur, count N is checked after each interrupt to determine if it has
`reached a limit C corresponding to an arbitrary amount of travel on the order of several
`meters. When the count limit C is reached, a test is made to determine if Cl) is within arbitrary
`limits (say :5 degrees to allow for lane changes, slight road curvature, etc). If so, it} is reset to
`tho (the direction of the vector being traveled) and N is set to 0 to start another cycle of moni~
`toting for unexpected heading changes.
`In addition to verifying that the vehicle stays on the route between nodes, this process
`removes error in measured vehicle heading that accumulates while U<N<C If the preceding
`test finds it to be outside the limits, the vehicle is presumed to have turned off the route (per-
`haps into an unmapped driveway or parking lot) and other routines are called into play. For
`example, route recovery instructions could be issued.
`When the vehicle approaches within an arbitrary distance (cg, 75 In) of a node where a
`change in vehicle heading should occur, the turn flag is set and a route guidance instruction is
`issued, giving the direction of the turn and, if appropriate, the name of the next road.The algo-
`rithm then monitors for changes in q: to confirm that the midpoint of the expected turn is
`reached within an arbitrary limit (e.g., 10 in) of the value of L specified for the node, and after-
`wards to confirm that the turn is completed.
`
`643
`643
`
`

`

`29.10
`
`EMERGING TECHNOLOGIES
`
`Upon reaching the midpoint, the current value of L is adjusted to that specified, thus
`removing any error in the measured distance accumulated since the last turn. If the expected
`turn is not confirmed within the allowed limits on distance L, the vehicle is assumed to have
`missed the turn or to have taken an alternate turn (see dashed lines in Fig. 29.42)) and other
`routines may be called to identify the alternate route taken from the node.
`The semideterministic algorithm concept outlined here may be extended to tracking a
`vehicle’s location as it moves over arbitrary routes within a road network rather than follow-
`ing a preplanned route. As long as the vehicle stays on roadways defined by a vector-encoded
`digital map, the vehicle must exit each node via some vector. Thus, a map-matching algorithm
`can identify successive vectors traveled by measuring the direction of vehicle travel as it
`leaves each node and comparing the vehicle direction with that of various vectors emanating
`from the node.
`
`Probabilistic. An enhanced type of map-matching algorithm is required for tracking vehi-
`cles not presumed to be constrained to the roads. When the vehicle departs from the defined
`route or road network (e.g., into a parking lot), or appears to depart as a result of dead-reck-
`oning error, the routine repeatedly compares the vehicle’s dead-reckoned coordinates with
`those of the links surrounding the off-road area which encompasses the vehicle location in
`order to recognize where the vehicle returns to the road network. Unlike while traveling on
`defined roadways, map-matching adjustments do not prevent accumulation of dead—reckon—
`ing error. Thus, depending upon the distance traveled off road and the accuracy of the dead-
`reckoning sensors, there may be considerable uncertainty in vehicle coordinates, which could
`produce misleading conclusions when tested against the surrounding links.
`Probabilistic map-matching algorithms minimize the potential of off—road errors by main-
`taining a running estimate of uncertainty in dead—reckoned location, which is considered in
`determining whether the vehicle is on a street.The estimate of location uncertainty is reduced
`each time it is deemed that the vehicle is on a street, but the uncertainty resumes growth in pro-
`portion to further vehicle travel until the next match occurs. Thus, a probabilistic algorithm
`repeatedly asks, “Where is the vehicle?,” with no a priori presumption that it is on a road.
`
`29.3 EXAMPLES OF NAVIGATION SYSTEMS
`
`Figure 29.6 is a block diagram showing the major elements of a typical automobile navigation
`system. Distance and heading (or heading change) sensors are almost invariably included for
`dead—reckoning calculations which, in combination with map matching, form the basic plat-
`form for keeping track of vehicle location. However, dead reckoning with map matching has
`the drawback of occasionally failing due to dead-reckoning anomalies, extensive travel off
`mapped roads, ferry crossings, etc.
`The location sensor indicated by dashed lines in Fig. 29.6 is an optional means of providing
`absolute location to avoid Occasional manual reinitialization when dead reckoning with map
`matching fails. Although proximity beacons serve to update vehicle location in a few systems
`(particularly those that also use proximity beacons for data communication), most state-of-
`the-art systems use GPS receivers instead.
`The recent evolution and present trends of automobile navigation and route guidance sys—
`tems are illustrated by the following examples.
`
`29.3.1 Etak NavigatorTM/Bosch TravelpilotTM
`
`The Etak, Inc. NavigatorTM introduced in California in the mid-19805 was the first commercially
`available automobile navigation system to include digitized road maps, dead reckoning with
`
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`

`NAVIGATION AIDS AND IVHS
`
`29.1 1
`
`MAP DATA
`BASE
`
`NAVIGATION
`COMPUTER
`
`.J
`
`
`DISTANCE
`HEADING
`
`SENSOR
`SENSOR
`
`
`
`|
`LOCATION
`l
`SENSOR
`i---:
`I
`|________J
`
`|I|
`
`______ __
`'
`'
`
`DATA
`
`FIGURE 29.6 Typical components and subsystems of vehicle navigation system.
`
`map matching, and an electronic map display. It used a flux—gate compass and differential
`odometer for dead reckoning. The equivalent of two printed city street maps were vector
`encoded and stored on 3.5—Mb digital cassettes for map matching and display purposes.
`Although sales were modest, the highly publicized Etak Navigator drew widespread attention
`to the concept of an electronic map display with icons showing current location and destination.
`The Travelpilot, which is essentially a second generation of the Navigator, was jointly
`designed by Etak, Inc. and Bosch Gmbflf‘ It was introduced in Germany in 1989 and in the
`United States two years later. One of the most conspicuous enhancements was the use of CD—
`ROM storage for digitized maps. The 640—Mb capacity permits the entire map of some coun—
`tries to be stored on a single CD—ROM.
`Like its predecessor, the Travelpilot displays a road map of the area around the vehicle, as
`illustrated by Fig. 29.1The vehicle location and heading is indicated by the arrowhead icon
`below the center of the screen. The vertical bar at the right edge of the map indicates the dis—
`
`Destination
`
`Destination
`
`North
`
`Between Two Stars
`
`
`
`Zoom Out
`
`‘ Main Menu '-
`
`* Map Top North
`
`
`Map Scale
`1!8 - 30 mi.
`
`Destination Into _
`1 mile
`Other St. Names 3‘
`
`shown
`
`
`Shift Cursor
`Zoom In
`Left orfiight
`
`Current Location I
`Current
`
`and Direction
`Destination
`
`of Travel
`Brightness
`‘ Ne access when vehicle is moving.
`comm]
`FIGURE 29.? Bosch Travelpilot display and controls. (Bosch titeramre)
`
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`

`29.12
`
`EMERGING TECHNOLOGIES
`
`play scale which can be zoomed in to % mile for complete street detail or out to 30 miles to
`show only major highways. The map is normally oriented such that the direction in which the
`vehicle is heading points straight up on the display, thus allowing the driver to easily relate the
`map display to the View outside.
`When parked, a menu accessible through the MEN button permits use of soft-labeled but-
`tons in a scrolling scheme to enter destinations by street address, intersection, etc.Travelpilot
`uses a process called geocoding to locate an input destination and display it as a flashing star
`on the map. As illustrated in Fig. 29.7, a destination geocoded by street address is bracketed
`by two flashing stars when the map is zoomed in. In this case, the stars mark the block whose
`address range includes the street number of the destination. A line of information across the
`top of the map display indicates the crow—flight distance and points the direction from the
`vehicle’s current location to the destination. Up to 100 input destinations may be stored for
`future use.
`
`A submenu provides several methods for the driver to reset the vehicle’s position on the map
`if the Travelpilot gets off track. The frequency with which the system requires reinitializing
`depends upon dead-reckoning anomalies and the completeness and accuracy of the map data
`for the area being driven. For example, map matching typically fails once in a thousand miles
`when operating in an environment like greater Los Angeles or North Texas. As for location
`accuracy the rest of the time (i.e., with map-matching operative), Travelpilot is claimed to have
`infinitesimal error relative to the map. The map-matching performance is compared to that of a
`servo—amplifier in which map—matching failure corresponds to loosing servo—look to the map.
`The Travelpilot hardware includes a V50 processor, 1A-Mb DRAM, 64-Kb EPROM, and 8
`Kb of nonvolatile RAM for storing vehicle location while the ignition is off, calibration fac—
`tors, up to 100 saved destinations, etc. The Travelpilot may interact with other devices through
`an RS—232 serial port and an expansion card slot. For example, Travelpilots in 400 Los Ange—
`les fire trucks and ambulances are connected by digital packet radio to the city’s emergency
`control center. The emergency operators can monitor each vehicle’s location and status, and
`can send destinations directly to a vehicle’s Travelpilot for emergency dispatch.
`
`29.3.2 Toyota EIectro-Multivision
`
`The Toyota Electro-Multivision has undergone numerous refinements since it was introduced
`in 1987 as the first sophisticated navigation system available as a factory option on automo—
`biles sold in Japan. Except for a few features, it is representative of the more comprehensive
`models of navigation systems now available in Japan from almost all of the major automobile
`and electronics manufacturers.
`
`Many Electro—Multivision features may be summarized with reference to those of the
`Travelpilot previously described in more detail. Both use dead reckoning and digitized maps
`stored on CD-ROM for display on a CRT screen with an icon representing present position,
`and are generally similar in their basic navigation features. However, a raster-scan color CRT
`rather than a vector—drawn monochromatic CRT is used in the Electro-Multivision. Also
`unlike Travelpilot, the Electro-Multivision map database includes yellow pages information
`such as the locations of facilities likely to be of interest to motorists.
`The Electro—Multivision also serves as a reference atlas. In the original version, for exam-
`ple, a display shows a color map of all Japan with 16 superimposed rectangles. Touching a par-
`ticular rectangle causes the map area it encompasses to zoom and fill the entire screen, again
`with grid lines superimposed to form 16 rectangles. Thus, a few touches of the screen takes the
`driver from an overview of the entire country down to major roads and landmarks in some
`quarter of Tokyo.
`However, in spite of Electro-Multivision’s sophisticated map-handling capabilities, map
`matching was not used in the first version because the digital maps then available for Japan
`did not contain sufficient detail at the city street level. In addition to detailed digital maps and
`map matching, subsequent versions of Electro-Multivision include a GPS receiver and a color
`
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`

`NAVIGATION AIDS AND IVHS
`
`29.13
`
`LCD rather than CRT display.6 In 1991, a routing feature was added to calculate a suggested
`route to specified destinations and highlight the trace on the LCD map display. The most
`recent version7 adds synthesized voice route guidance instructions.
`As is the case for most other state-of-the-art navigation systems offered as factory—
`installed equipment in Japan, the Electro—Multivision navigation features are integrated with
`a full suite of entertainment features (e.g., AM—FM radio, tape cassette, audio CD player, color
`TV, etc). In addition, the Electro-Multivision includes a CCD camera for rear vision on the
`LCD screen.
`
`29.3.3 Oldsmobile Navigation/Information System
`
`In January 1994, Oldsmobile announced its Navigation/Information System, the first naviga-
`tion and route guidance system to be offered as a dealer-installed option from an automobile
`manufacturer in the United States. Initially sold only in California, the system was expected
`to be offered nationwide as digital map databases for other areas become available during
`1994—1995.
`
`The Oldsmobile system integrates a GPS receiver with dead reckoning and map matching.
`The dead-reckoning process uses gyroscopic and odometer inputs. A PCMCIA card is used
`for storing a map database which includes the locations of points of interest such as emer—
`gency services, restaurants, major retail stores, schools, office buildings, tourist attractions, etc.
`The major hardware modules of the system are shown in Fig. 29.8.
`Destinations may be entered as specific street addresses or road intersections, or by select-
`ing categories and scrolling through the points of interest included in the database. Routing cri—
`teria (e.g., avoiding expressways) may also be specified. The navigation computer then
`calculates the route and highlights it on a 4-in active matrix color LCD. Once underway, the dis-
`tance to and direction of each turn is displayed on the screen and a voice prompt advises the
`driver as each turn is approached. A representative route guidance screen is shown in Fig. 29.9.
`The Oldsmobile Navigation/Information system is supplied by ZeXel USA Corp. and is an
`adaptation of Zexel’s NAVMATE system which has been under development for several
`years specifically for the US. market.
`
`29.3.4 TravTek Driver Information System
`
`Whereas these examples of automobile navigation systems are already available in certain
`markets, TravTek was a functional prototype of a navigation-based in—vehicle traveler infor-
`mation system developed specifically for the TravTek IVHS operational field trial conducted
`for a one—year period ending in 1993 in Orlando, Florida. The field trial was a joint public sec-
`tor—private sector project with the primary objective of obtaining field data on the acceptance
`and use by drivers of navigation and other information provided by comprehensive in—vehicle
`systems linked with traffic operations and other data centers.
`The TravTek project used 100 General Motors automobiles equipped with the system
`shown schematically in Fig. 29.10 to provide navigation, route selection and guidance, real-
`time traffic information, local yellow pages and tourist information, and cellular phone ser-
`vice.8 Most of the automobiles were made available to Orlando visitors through Avis Rent A
`Car for short-term trials and the rest were assigned to local drivers for extended periods. The
`American Automobile Association selected the test subjects and operated a TravTek Infor-
`mation and Services Center which could be accessed via cellular telephone.
`TravTek navigation is based on a combination of dead reckoning and map matching, with
`a GPS receiver playing a “watchdog” role. TravTek’s navigation function superimposes vehi-
`cle location on a map display screen, highlights suggested routes on the color CRT map dis-
`play, and issues route guidance instructions via synthesized voice. Alternatively, turn—by—turn
`route guidance instructions may be displayed in the form of simplified graphics.
`
`647
`647
`
`

`

`[Red] battery +14 v
`
`[Orange] ignition signal
`
`[Grey] speed sensor (V88)
`
`[Purple] back—up light signal
`
`
`
`
`
`
`
`+ Display bracket
`assemny
`
`wm
`
`
`
`
`
`Display unit
`
`(13!” DIN)
`
` Video cable
`
`
`
`
`Main wire harness
`I
`
`
`(5P AMP)
`II
`
`
`
`
`' - laf"
`
`
`GPS antenna
`
`Navigation
`computer
`
`+ Computer bracket
`assembly
`
`fl
`
`FIGURE 29.8 Oldsmobile Navigationlinformation System hardware. (Oldsmobile)
`
`Oldsmobile
`l—il'BB Fm WEST
`OLDS FM
`
`
`
`15 lfffllP
`
`"I'll!
`
`FIGURE 29.9 Oldsmobile Navigationflniorma—
`tion System route guidance screen. (Oldsmobile)
`
`29.14
`
`648
`648
`
`

`

`GPS Rcvr
`
`Rw Delog
`Shunt
`
`NAVICAR SW
`TravTek MODS
`WK "3? DB
`MA Direcro DB
`’Y
`
`He, Men
`
`Cellular
`Telephone
`
`NAVIGATION AIDS AND IVHS
`
`29.15
`
`Bo
`Sw'c‘uinlg
`switches
`T a d.
`0 a lo -
` ‘03!
`
`'ol‘l
`ar
`5
`H a
`Sum:th Swflcms
`
`Wheel
`
`ECM ALDL
`
`Faceplate
`Controller
`
`Switch Control
`
`£3“ W 53.0 Bus
`Serial Link
`
`Navigation
`
`Diagnostic
`Proce s r
`
`S 0
`Serial Link
`TravTek SW
`
`TravTek DB
`
`MA Map DB
`°°m'°"er
`cams
`
`"
`
`Production
`Control er
`Display
`
`
`“Sway
`
`Data
`Converter
`
`Video
`.
`
`5“"3'
`
`Dlagnoslic
`Serial Link
`
`“"3"”
`
`paella, ll
`
`.
`H/s Sw'tch
`controller
`
`To ecu. ecu
`E&C Bus
`
`N
`
`on
`
`Crook-
`
`Color Display
`
`Serial
`
`Routing
`Processor
`
`Serial
`
`RF
`Modem
`
`Serlal
`
`
`
`SMR.
`Transceiver
`
`To sum TIR
`Antenna
`
`Power
`Supply
`
`Removable
`Log File
`
`.
`speech
`Synth —’ Tonadlo
`
`FIGURE 29.10 Architecture of TravTek vehicle system.8
`
`Although functionally realistic, the TraVTek in—vehicle system design used some features
`that would not typically appear in a production system. For example, rather than consolidated
`databases stored on a single CD-ROM or other data storage device, TraVTek used separate
`map databases stored on separate hard disk drives for navigation processing and route guid-
`ance processing.9
`However, compared to these examples of commercially available navigation and route
`guidance systems, TraVTek’s most distinct difference was the capability to superimpose infor-
`mation on current traffic conditions on the map display and to take traffic congestion levels
`into account in calculating recommended routes. The traffic information was received over a
`radio link from a special Traffic Management Center (TMC) operated by the City of Orlando
`in conjunction with the Federal Highway Administration and the Florida Department of
`Transportation. The TMC consolidated traffic data from various sources including “probe”
`data consisting of road segment travel times received Via mobile radio from the TraVTek vehi-
`cles themselves.
`
`29.4 OTHER IVHS SYSTEMS AND SERVICES
`
`A central aspect of IVHS (Intelligent Vehicle—Highway Systems) is the operation of advanced
`traffic management systems (e.g., the TraVTek TMC outlined here) in conjunction with auto—
`mobile navigation and route guidance systems. This requires the use of mobile data commu-
`
`649
`649
`
`

`

`29.16
`
`EMERGING TECHNOLOGIES
`
`nication links between the infrastructure and in—vchicle systems. Although the United States,
`Europe, Japan, and other developed countries are now systematically pursuing IVHS devel—
`opment, selection of mobile data communication approaches remains under consideration as
`this handbook is prepared. However, it
`is generally expected that one or more of the
`approaches characterized in Table 29.1 will be selected for most geographical areas.
`
`TABLE 29.1 Characteristics of Alternative Mobile Data
`Communication Approaches
`
`
`Approach
`Characteristics
`
`FM sideband
`
`Proximity beacon
`
`Inductive loop
`
`Land mobile
`
`Specialized mobile radio
`
`Cellular radio
`
`Mobile satellite
`
`Meteor burst
`
`One—way
`Low data rates
`
`Extended area coverage
`One-way or two-way
`High data rates
`Spot area coverage
`One-way or two-way
`Low data rates
`
`Spot area coverage
`Two—way
`Local area coverage
`Two—way
`Extended area coverage
`Two—way
`Locala’extended area coverage
`One—way or two~way
`Wide area coverage
`Two-way
`Wide area coverage
`Involves time delays
`
`The vast scope of IVHS is made easier to comprehend by subdivision into several interre—
`latcd and overlapping categories that have been used to structure the IVHS program in the
`United States: Advanced Traffic Management Systems (ATMS), Advanced Traveler Informa—
`tion Systems (ATIS},Advanced Vehicle Control Systems (AVCS). CommercialVehicle Oper-
`ations (CVO), Advanced Public Transportation Systems (APTS), and Advanced Rural
`Transportation Systems (ARTS).
`
`29.4.1 Advanced Trafiic Management Systems lATMSl
`
`ATMS includes freeway surveillance and incident detection, changeable message signs, elec—
`tronic toll collection, and coordination of traffic signal timing over wide areas in response to
`real—time traffic conditions Major elements of ATMS have been around for decades. The first
`computerized traffic signal control systems were developed in the 1960s, and approximately
`200 computerized traffic signal control systems were in use in North America by the end of
`the 19805. About 25 major freeway surveillance and control systems were in use, including
`many dating from the 19603 and 19?0s Electronic toll collection did not start experiencing sig-
`nificant implementation until the 19905.
`An additional AIMS function is to supply real—time traffic information (cg, link travel
`times) over mobile data communication links to ATIS.The final selection of one or more com—
`munication links is unsettled because, among other things, their requirements (e.g., data rates)
`are highly dependent upon system architecture and the division of functions between infra—
`structure and in—vehicle equipment.
`
`650
`650
`
`

`

`29.4.2 Advanced Traveler Information Systems (ATIS)
`
`NAVIGATION AIDS AND IVHS
`
`29.17
`
`ATIS systems acquire, analyze, communicate, and present information to assist surface trans—
`portation travelers in moving from one location to another. Initially called ADIS (Advanced
`Driver Information Systems) by Mobility 2000 and essentially limited to navigation, route
`guidance, and traffic information presented by in-vehicle systems, ATIS concepts now also
`encompass the provision of transit schedules and connections to home, office, kiosk and hand—
`held PPATIS (Portable ATIS) units as well as in-vehicle units. Vision enhancement devices for
`drivers also fall under the ATIS category.
`Although PPATIS concepts are proliferating, most early ATIS market activity is expected
`to be what was originally called ADIS and will be centered on in-vehicle navigation and route
`guidance systems. A 1991 Delphi study by the University of Michigan forecasts some form of
`navigation incorporating GPS will be used in 5 percent of all vehicles sold annually by 2000
`and in 50 percent by 2012. IVHS strategic planning assumes that manufacturers will sell 2.5
`million vehicles annually with factory-installed ATIS by the year 2000.
`The potential of the ATIS market is also illustrated by the fact that approximately 500,000
`sophisticated automobile navigation systems had already been sold (mostly as factory
`options) in Japan by the end of 1993, even though they must operate autonomously because
`mobile communication links to ATMS traffic operations centers for enabling dynamic route
`adjustment according to traffic conditions have thus far been limited to developmental tests.
`
`29.4.3 Advanced Vehicle Control Systems (AVCS)
`
`Whereas ATIS assists drivers by providing information to facilitate efficient and safe opera—
`tion, AVCS provides direct assistance with vehicle control. An existing example is ABS
`(antilock braking system). Other early forms of AVCS include obstacle detection and warn-
`ing systems and intelligent cruise control. Intelligent cruise control automatically adjusts
`speed according to distance and speed of the vehicle being followed, and enables platooning
`concepts wherein closely spaced vehicles travel in groups to increase lane capacity and safety.
`AVCS may ultimately lead to fully automated chauffeuring.
`Most of the more advanced forms of AVCS such as automatic lane keeping (lateral steer-
`ing control) are still in the laboratory stage. Although driver warning, perception enhance-
`ment, and assistance/control systems are under active research and testing in the United
`States, Europe, and Japan, the most comprehensive demonstrations to date have been accom-
`plished under Europe’s PROMETHEUS program.
`
`29.4.4 Commercial Vehicle Operations (CVO)
`
`In addition to benefiting from ATMS, ATIS, and AVCS functions, commercial vehicle opera—
`tions may be made more productive through additional IVHS functions. These include auto-
`matic vehicle location monitoring, computerized dispatch and fleet management systems for
`dynamic scheduling and routing, Weigh—in—motion (WIM), automatic vehicle classification
`(AVC), automatic vehicle identification (AVI), on—board data acquisition computers, etc.
`The earliest CVO applications were for managing critical urban fleets (e.g., police vehicles
`starting in the 1970s). However, extensive application of communication and location report—
`ing schemes to long-distance trucking fleets got underway in the 19805. Much of the present
`CVO activities (e.g., AVI, AVC, WIM) focus on this application with the objective of elimi-
`nating stops and regulatory paperwork now required when traveling from state to state.
`
`29.4.5 Advanced Public Transportation Systems (APTS)
`
`APTS encompasses some forms of CVO (e.g., automatic vehicle location reporting), as well
`as additional functions such as schedule monitoring for transit buses. APTS also includes
`
`651
`651
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`

`

`29.18
`
`EMERGING TECHNOLOGIES
`
`HOV (high-occupancy vehicle) lanes and instant car—pooling services. Although AVL imple—
`mentation for transit buses was limited until the present generation of GPS—based systems
`started becoming available, extensive research and trials were conducted during the 19705
`under auspices of the Urban Mass Transit Administration (recently renamed Federal Transit
`Administration). The use of AVL and communications technologies to monitor, control, and
`manage public transit continues to be a central thrust of APTS.
`New APTS thrusts include making timely and accurate information on traffic conditions
`and on transit and ride-sharing alternatives readily available to travelers (especially com-
`muters who normally drive alone) for pretrip planning. Another is to improve the customer
`interface through the use of integrated electronic fare systems such as smart cards valid for all
`transportation modes, and through the provision of real-time transit service information at
`homes, offices, and public places as well as at stops, aboard vehicles, etc. APTS also includes
`systems for controlling HOV access and enforcing proper usage.
`
`29.4.6 Advanced Rural Transportation Systems (ARTS)
`
`ARTS has the greatest overlap with other segments of the IVHS industry in that few, if any,
`additional functions or technologies are required. Instead, safety dominates rural IVHS plan—
`ning with emphasis on in—Vehicle safety advisory and warning systems, prevention of single—
`vehicle off-road accidents, prevention of passing accidents, warnings of animals on or near the
`roadway, vision enhancement, and Mayday calls from stranded vehicles. Although virtually all
`of these may evolve under other IVHS segments, ARTS communications considerations dif-
`fer significantly from those of urban areas because lower population densities and fewer
`roads combined with greater distances among facilities require greater dependence upon
`wide—area communications.
`
`REFERENCES
`
`5.
`
`1. R. L. French, “Historical overview of automobile navigation technology,” Proceedings, 36th IEEE
`Vehicular Technology Conference, Dallas, Texas, May 20—22, 1986, pp. 350—358.
`2. D. A. Rosen, Mammano, F. J., and Favout, R., “An electronic route guidance system for highway vehi—
`cles,” IEEE Transactions on Vehicular Technology, vol.,VT—19, 1970, pp. 143—152.
`3. R. L. French, “Evolution of automobile navigation in Japan,’7 Proceedings, 49th Annual Meeting of the
`Institute of Navigation, Cambridge, Massachusetts, June 21—23, 1993, pp. 69—74.
`4. R. L. French, “Map matching origins, approaches, and applications,” Proceedings, Second International
`Symposium on Land Vehicle Navigation, Munster, Germany, July 4—7, 1989, pp. 93—116.
`J. L. Buxton, Honey, S. K., Suchowerskyj,W. E., and Tempelhof, A., “The Travelpilot: a second—genera-
`tion automotive navigation system,” IEEE Transactions on Vehicular Technology,” vol. 40, no. 1, 1991,
`pp. 41—44.
`6. K. Ishikawa, Ogawa, M.,Azuma, S., and Ito, T., “Map navigation software of the Electro-Multivision of
`the ’91 Toyota Soarer,” Proceedings, VNIS’9Z———Vehicular Navigation & Information Systems Confer—
`ence, vol. 1, Dearborn,