Showing papers in "IEEE Transactions on Vehicular Technology in 1970"
TL;DR: A highway transportation subsystem which could be implemented in the near future, and which retains the driver as an integral part of the system, but is expected to enhance the driver's performance by unburdening his route guidance task and allowing more attention to the primary task of controlling the vehicle is presented.
Abstract: The electronic route-guidance system (ERGS) is the result of an effort by the Office of Research and Development, Bureau of Public Roads, to develop a new concept for guiding the motorist. To implement the concept, a system has been developed which makes use of electronic equipment both in the participating vehicles, and at intersections which are to supply guidance instructions. The system is destination oriented. The driver enters a code word, representing his intended destination, into the vehicle equipment. Then as the vehicle approaches each instrumented intersection, the destination code is transmitted to the roadside where it is decoded, according to a stored program, and a routing instruction is transmitted back to the vehicle. In the vehicle, the routing instruction is displayed to the driver in the form of a symbol or word message, which gives the maneuver the driver should make at the upcoming intersection or interchange to reach his destination optimally. The development of the system from its conception to its future application and benefits are discussed. The descriptions of today's highway routing problems in the "static" and "dynamic" situations are presented, then the outline of the Bureau of Public Road's developmental effort and the major contributions of its various contractors is discussed; Philco-Ford's development of a destination coding system and techniques for solving optimal routings, General Motors Corporation's development of an installed and operating engineering model, Serendipity's determination of driver-information requirements for ERGS, and Kollsman Instrument Corporation's development of an automobile head-up display for the ERGS routing symbols. A separate section gives a description of the General Motors system design at the functional and component level. Future development and system benefits are discussed. Dynamic system requirements over and above the present or static ERGS are envisioned, including both additional hardware and software. Benefits to the highway system and to the highway user are given for the static or preprogrammed system and for the dynamic system. A highway transportation subsystem which could be implemented in the near future, and which retains the driver as an integral part of the system, but is expected to enhance the driver's performance by unburdening his route guidance task and allowing more attention to the primary task of controlling the vehicle, is presented. Furthermore, the addition of central control facilities and communications links to intersections is expected to permit more uniform distribution of traffic over the highway network.
84 citations
TL;DR: In this paper, the essential properties of small-zone systems are generalized to show that zone size alone is not an adequate parameter to distinguish large-from-small-zone system.
Abstract: Parameters of a large-scale highly coordinated mobile telephone system are discussed, particularly those of system size and frequency spectrum required. The concept of small-zone coverage areas to serve large customer densities is discussed, and the essential properties of small-zone systems are generalized to show that zone size alone is not an adequate parameter to distinguish large- from small-zone systems. A high-capacity small-zone system model using several zone sizes is presented. Advantages of small-zone operation other than spectrum economy are enumerated, as are the attendant disadvantages.
72 citations
TL;DR: In this paper, three different electromagnetic loop vehicle detector designs are described: self-tuning, bridge balance, and phase shift, and principles of operation, design limitations, and design trade-offs for each method are presented in detail.
Abstract: Three different electromagnetic loop vehicle detector designs are described: self-tuning, bridge balance, and phase-shift. Principles of operation, design limitations, and design trade-offs for each method are presented in detail. The characteristics of the lead-in wire used are shown to be the primary limitation in loop detector performance and stability. Characteristics of commercially available wire used in present-day loop detector installations are discussed. Design equations and graphs illustrate the tradeoff considerations in the determination of optimum loop configuration and inductance.
50 citations
TL;DR: The history of traffic signals is traced from the signal fires which guided early man to the sophisticated electromechanical signal devices of today, and early experiments with officer-operated semaphores, lanterns, and electric lights are discussed.
Abstract: The history of traffic signals is traced from the signal fires which guided early man to the sophisticated electromechanical signal devices of today. Early experiments with officer-operated semaphores, lanterns, and electric lights are discussed. The influence of railroad signaling is noted, as are the innovative efforts of inventors who saw the problems of congestion and hazard developing to the point where control measures were essential. Descriptions of several devices show the imagination of early practitioners, and one may reflect with some humor on what might have been developed for use today. Some of the earliest attempts at automatic control even made use of the policeman's whistle, blown by a small compressor, while later efforts included clanging bells as a substitute. The extent to which some of these quite primitive devices survived in actual use into the post-World War II era is remarkable; devices unique to an area often hung on, long beyond the time when they were made obsolete by newer devices. Credit is given to several pioneers in the field, along with appropriate references to the few who have contributed to preservation of parts of the history of this interesting subject.
46 citations
TL;DR: In this article, the physical characteristics of the various required subsystems for vehicle guidance and control and the optimum operation of the overall highway system are discussed, together with the complex interrelationships which exist among them.
Abstract: Highway automation is an attractive possible solution to some of the problems posed by an ever-increasing number of motor vehicles, as it would probably result in substantial increases in traffic-flow rates and a dramatic reduction in the numbers of highway accidents and fatalities. One practical system involves a roadway complex of the future, consisting of both automated and nonautomated roads, which will have evolved in an orderly and progressive manner from the roadway system of today. Only the main highways would be automated, and dual-mode vehicles would be used. The two major related technical areas in this framework are the physical characteristics of the various required subsystems for vehicle guidance and control and the optimum operation of the overall highway system. The elements of the former are divided into eleven categories: automatic longitudinal control, vehicle-spacing detection, communication systems, automatic lateral control, automatic merging control, controlled lane changing, vehicle propulsion, system decision-making capability, compatible manual mode, automatic vehicle checkout, and evolutionary developments. The role and state of the art of each category are discussed in detail, together with the complex interrelationships which exist among categories. Although some research has been accomplished, substantial future research and development progress will be necessary before an automated highway system is a practical reality.
27 citations
TL;DR: In this article, three different physical phenomena are discussed as applied to the detection of roadway vehicular traffic, and a comparative analysis is made of radar, acoustical, and magnetic detectors, as well as mechanical, magnetic, induction, and optical detectors.
Abstract: Three different physical phenomena are discussed as applied to the detection of roadway vehicular traffic. These detectors are the input data sources for vehicle-actuated traffic signal light control mechanisms, control systems, freeway surveillance, and statistical analysis. Radar detectors using microwave radio frequencies in the 2.5-10 MHz are discussed with regard to operating principles, design consideration, and practical application. Similarly, acoustical detectors operating in the 20-kHz range and low-flux density change magnetic detectors are discussed. A comparative analysis is made of radar, acoustical, and magnetic detectors, as well as mechanical, magnetic, induction, and optical detectors.
14 citations
TL;DR: In this paper, the authors present the design of these systems as well as the methods that have been proposed and/or developed using the other sensing technologies, including magnetic, infrared, optical, sonic, radioactive, radio frequency (RF) transmission, microwaves, have been surveyed and investigated to determine their applicability for an automatic vehicle identification (AVI) system.
Abstract: Many agencies, both governmental and private, in the highway transportation field need a system which would automatically identify motor vehicles. The basic concept of such a system requires a vehicle-mounted coded device, a transponder, that uniquely identifies that vehicle. As this vehicle comes within the range of a system interrogator installed along or on the highway, the code is read by this interrogator and the identification of the vehicle is obtained. The ideal transponder is passive and requires no power; has no effect on, and is not affected by the vehicle; does not require physical contact with the interrogator, and requires no action by the vehicle operator. Sensing at a distance (noncontact) involves the detection of some type of energy; either radiated or reflected from the object being monitored. Many different sensing techniques, including magnetic, infrared, optical, sonic, radioactive, radio frequency (RF) transmission, microwaves, have been surveyed, investigated, and analyzed to determine their applicability for an automatic vehicle identification (AVI) system. This analysis has concluded that a low-frequency induction system is presently the most appropriate method for use on the highway environment, Several diverse systems differing in design details have been constructed and tested, utilizing this basic technique. This paper describes the design of these systems as well as the methods that have been proposed and/or developed using the other sensing technologies.
12 citations
TL;DR: In this article, the use of the spectrum allocated to the land mobile radio service is discussed and the following fundamental technical questions concerning the spectrum allocation are discussed: 1) Is it technically feasible to increase the number of assignable channels within the allocated spectrum space? 2) Are other modulation methods more or less suitable for providing more channels?
Abstract: The following fundamental technical questions concerning the use of the spectrum allocated to the land mobile radio service are discussed. 1) Is it technically feasible to increase the number of assignable channels within the allocated spectrum space? 2) Are other modulation methods more or less suitable for providing more channels? The primary resource material used to answer these questions is the response of the Land Mobile Section, Industrial Electronic Division, Electronic Industries Association [49]. Only the frequency spacing question is treated in this paper.
12 citations
TL;DR: System parameters to be discussed will include: spectrum efficiency, Federal Communications Commission licensing considerations, required and achievable location accuracies, data-system speeds and reliability, and elements of cost effectiveness analysis.
Abstract: Various land mobile communities are actively seeking new tools which will offer significant improvements in the efficiency with which they manage the operations of their mobile fleets. The various types of location and information reporting techniques which can be used to supplement existing voice-radio communications to achieve this goal are described. Both fixed- and random-route location systems will be considered in terms of system characteristics as these relate to the needs of specific user groups such as law enforcement agencies and transportation organizations. The location techniques considered will include electronic signposts, trilateration (direct measurement using both wide-band (pulse) and narrow-band (phase) modulation), and automatic navigation systems. System parameters to be discussed will include: spectrum efficiency, Federal Communications Commission licensing considerations, required and achievable location accuracies, data-system speeds and reliability, and elements of cost effectiveness analysis. Finally, requirements for other types of vehicular information which are needed to produce a practical total system will be explored.
11 citations
TL;DR: In this article, the frequency and range variations of composite incidental man-made radio noise power in metropolitan areas have been analyzed using a knowledge of the propagation characteristics of irregular surface terrain for low-height antennas and the noise-source spectral power densities for a Poisson distributed random noise process.
Abstract: The surface distribution of composite incidental man-made radio noise power in metropolitan areas displays frequency and range variations which are predictable from a knowledge of the propagation characteristics of irregular surface terrain for low-height antennas and the noise-source spectral power densities for a Poisson distributed random noise process. The observed frequency variation of composite surface noise power in the very-low-frequency (VLF) through the lower very-high-frequency (VHF) band is porportional to the product of 1) the inverse first power of frequency, introduced by irregular terrain basic path loss dispersion for low antennas, and 2) the inverse quadratic frequency dependence of the noise-source spectral density. In the upper portion of the VHF band and in the ultrahigh-frequency (UHF) range, the basic path loss dispersion remains unchanged while the emission spectrum of the surface noise sources asymptotically approaches that of band-limited white noise. The observed first-order surface range dependence for composite man-made noise within an urban area is predictable from the measured variation of irregular terrain basic path loss for low-height antennas and displays a somewhat smaller exponent than the free space propagation function. The general range function for composite metropolitan area man-made noise power displays a quadratic exponential variation with distance from the urban center. The level of man-made noise power, observed from 1 to 5 miles above metropolitan areas, can be related to the surface noise distribution, the radiation pattern of the receiving antenna, and the coordinates of the airborne detector, relative to the urban center. The noise level, the noise spectral density, and the position dependence of the airborne noise power are predictable from this information plus a recognition that, as the receiver field of view increases with altitude or beamwidth, the amplitude distribution of the surface sources approaches a unit normal distribution in conformity with the central limit theorem for multiple independent random sources. Tests of the validity of the theoretical predictions of the range and frequency dependence of both surface and airborne man-made incidental radio noise power in the VHF-UHF bands have been performed, using accumulations of both surface and airborne noise data obtained from measurements in and above urban areas in Europe, Asia, Australia, and North and South America. Theoretical and experimental comparisons have confirmed the validity of the noise generation and propagation models and support their use for calculating the deterministic characteristics of metropolitan area incidental man-made noise.
11 citations
TL;DR: In this paper, the authors present some of the economic and technical considerations for development of future noncooperative vehicle-detector systems, including accuracy requirements, installation cost, location, and the roadway environment.
Abstract: This paper presents some of the economic and technical considerations for development of future noncooperative vehicle-detector systems. Vehicle-detector accuracy requirements, installation cost, location, and the roadway environment are used to develop a set of preferred vehicle detector characteristics. In addition, a description of vehicle detectors, considered for development by the Bureau of Public Roads, and some of the current vehicle-detector concepts under development, are presented.
TL;DR: The dispersed array mobile radio system as mentioned in this paper represents a radical new approach to the problem of spectrum congestion in the land-mobile radio service, which provides a very substantial improvement in spectrum utilization over the present mode of operation and at a cost to the user of about 20 percent less.
Abstract: The dispersed array mobile radio system represents a radical new approach to the problem of spectrum congestion in the land-mobile radio service. This new approach provides a very substantial improvement in spectrum utilization over the present mode of operation and at a cost to the user of about 20 percent less. Spectrum efficiency is achieved by a dynamic combination of space, time, and frequency diversity. Cost reduction is achieved because the mobile radio unit is a compact low-power short-range all solid-state transceiver.
TL;DR: In this article, the response of an untuned 16.5-foot vertical whip antenna mounted on the rear comer of a jeep, relative to a half-wave horizontal dipole at 15 feet above ground, was measured at high frequency with an ionospheric sounder.
Abstract: The response toward the zenith of an untuned 16.5- foot vertical whip antenna mounted on the rear comer of a jeep, relative to the response of a half-wave horizontal dipole at 15 feet above ground, was measured at high frequency with an ionospheric sounder. At 4 MHz, the relative response of the whip was -52.5 dB, and it increased with frequency at a rate greater than 12 decibels per octave (i.e., greater than frequency to the fourth power). The absolute power gain of the whip at 4 MHz was estimated at about -37.5 dB, ±6 dB relative to an isotropic radiator, and the variation with frequency was approximately a fifth-power law [i.e., G p ≈ -70 + 55 log 10 (f MHz ) dB] in the frequency range of 4 to 8 MHz. The short-path sky-wave signal received by the untuned whip can be enhanced by about ±10 dB, ±4 dB relative to that received with a vertical whip, by bending the whip away from the vehicle at an angle of 30° or more. When the same whip is bent forward and tied down over the hood of the vehicle, the received sky-wave signal is enhanced by only +3 dB, ±4 dB. These results should apply regardless of whether the vehicle is traveling in open or wooded terrain.
TL;DR: In this paper, a two-way communications system for highway right-of-way is proposed, in which a stable roadside frequency is transmitted from the local headquarters' control point and confined to the highways on an F 1 -F 1 repeater system.
Abstract: As part of the future improvement of the nation's highways, the Bureau of Public Roads is planning a two-way communications system. This system will incorporate various sensors to provide for better control and also many safety and convenience services which would be desirable for more efficient use of the highways. A unique radio system confined to highway right-of-way which is economical and has the inherent growth capability which would be required for a nationwide system is outlined. The design concept makes use of recently developed F 1 -F 1 repeater techniques which would result in a nationwide system requiring only two radio frequencies, one from the headquarters' control to the cars or trucks and one from the car to the headquarters. The highly stable roadside frequency is transmitted from the local headquarters' control point and confined to the highways on an F 1 -F 1 repeater system. The car equipment is a transponder unit whose frequency is controlled by the highway system. Automatic location identification of the car signal is provided. Signals can be either voice or digital. For growth and integration with other special services such as car or truck identification, traffic control, route guidance, etc., time-sharing channels can be added to both the highway system and to those cars that require it.
TL;DR: A computer-directed traffic-control system is described which is intended to increase the efficiency and safety of the merging maneuver by detecting and tracking gaps in the merging lane of the freeway and by dynamically controlling ramp vehicles into these gaps.
Abstract: A computer-directed traffic-control system is described which is being designed under the sponsorship of the Bureau of Public Roads. The system is intended to increase the efficiency and safety of the merging maneuver by detecting and tracking gaps in the merging lane of the freeway and by dynamically controlling ramp vehicles into these gaps. This system is also concerned with optimizing throughput in the freeway corridor by distributing traffic demand between the freeway facility and supporting network of arterial streets. The description of this system is supported by a treatment of the parametric relationships governing traffic control on freeway, and reference to the historical development of merging control systems.
TL;DR: In this paper, a closed-circuit television system for displaying contours of constant illumination intensity is described, which is capable of rapidly performing vehicle-mounted headlamp testing per SAE-J579a and could be adapted for use at state inspection stations.
Abstract: Automobile headlamp illumination is of concern because uniformity and shape of the beam pattern are quite important for optimum road visibility and safety for oncoming drivers. The Society of Automotive Engineers' specification on headlamp illumination [1] designates the maximum and minimum intensities at several spots within the beam. Many states require inspection of vehicle-mounted headlamps for illumination and aiming, and this test is commonly performed using a device which clamps on the headlamp lens. This clamp-on device is limited to checking the maximum intensity at beam center, rather than checking the overall beam pattern to the SAE-J579a specifications. In addition, mechanical limitations of this device have often resulted in the mis-aiming of vehicle headlamps. Present instrumentation available for measuring light intensity per SAE-J579a is primarily of the photo-cell type device, and the point-to-point measurement of light intensities is quite tedious and time consuming. A technique is described in this paper which incorporates electronic signal processing into a closed-circuit television system for displaying contours of constant illumination intensity. The technique is capable of rapidly performing vehicle-mounted headlamp testing per SAE-J579a and could be adapted for use at state inspection stations.
TL;DR: Analysis of potential communications systems demonstrates that a one-mile interval terminal design providing two-way voice communication between the motorist and an aid dispatch center provides the best benefit-cost ratio consistent with a satisfactory level of service.
Abstract: The nature and magnitude of the demand for emergency communications generated by users of rural freeways is described. A classification diagram of potential communications systems is presented and a preliminary selection of candidate systems is made on the basis of overall technical and economic considerations. The operating efficiency of the selected systems is analyzed in terms of their estimated detection efficiency and detection time performance. This analysis when combined with system cost projections demonstrates that a one-mile interval terminal design providing two-way voice communication between the motorist and an aid dispatch center provides the best benefit-cost ratio consistent with a satisfactory level of service. The operational characteristics of the selected system are described in some detail.
IBM1
TL;DR: In this article, the use of digital computers in traffic is becoming more common, after years of experimentation and promise, and the theoretical requirements of such systems and a description of the physical and programming characteristics of systems in operation in several locations in the United States are dealt with.
Abstract: The use of digital computers in traffic is becoming more common, after years of experimentation and promise. Both the theoretical requirements of such systems and a description of the physical and programming characteristics of systems in operation in several locations in the United States will be dealt with. The improvements in traffic flow and the managerial, manpower, and organizational requirements will be discussed. Finally, the probable short-range and long-range direction of new systems will be hypothesized.
TL;DR: The motoring public is increasingly conscious of the fact that the U. S. street and highway systems is rapidly becoming choked with vehicles and it is necessary to ensure the proper balance between the various modes of transportation, air, water, road, guided or tracked vehicles, and the substitution of communications for personal travel.
Abstract: The motoring public is increasingly conscious of the fact that the U. S. street and highway systems is rapidly becoming choked with vehicles. In many instances the answer to this problem does not lie in pouring more concrete. Instead it is necessary to first, ensure the proper balance between the various modes of transportation, air, water, road, guided or tracked vehicles, and in some cases the substitution of communications for personal travel; second, research and development (RD and cost must be within an acceptable range.
TL;DR: A moving-base car-following simulator was designed and constructed and closely approximated results from corresponding highway experiments; thus, the simulator can be used to obtain valid data pertaining to the driver-vehicle system in such studies.
Abstract: A moving-base car-following simulator was designed and constructed for studying the driver-vehicle system under various simulated highway conditions. The simulator consists of four primary components-- a moving-base cockpit, a model lead car on a variable-speed treadmill on which a two-lane road is continuously positioned, a closed-circuit television system, and a laboratory analog computer--which are described in detail. The results obtained in car-following studies using this simulator closely approximated results from corresponding highway experiments; thus, the simulator can be used to obtain valid data pertaining to the driver-vehicle system in such studies. However, the simulator is characterized by several disadvantages that limit the range of its applications. These disadvantages are discussed, and various highway situations that can be effectively studied are described.
TL;DR: A comprehensive traffic-flow control and stoppage-detection system now being implemented is also discussed, which will employ four small-scale digital computers working in pairs at both the Holland and Lincoln Tunnels.
Abstract: A description of an operational vehicular tunnel traffic-flow control system is presented. Using photoconductive cells as vehicle detectors in the Lincoln Tunnel South Tube and a fixed logic hardware controller to activate traffic signals and signs at the tunnel entrance, traffic is metered in a manner which results in less congestion. The vehicle detectors use wall-mounted high-intensity light sources aimed at a cell which is located below a hole in the tunnel roadway. The cell is hard-wire connected to the logic controller. The controller, using discrete solid-state components, determines the number of vehicles between two points in a tunnel lane; in addition the controller calculates the speed of each vehicle at both points. Using these parameters, the controller decides if the entering traffic-flow rate should be lowered. If a decrease in the rate is warranted, amber traffic signals and a sign which states "pause here-then go" is then energized. When the threat of possible congestion is alleviated, the entrance controls are automatically de-energized by the controller. A comprehensive traffic-flow control and stoppage-detection system now being implemented is also discussed. This system will employ four small-scale digital computers working in pairs at both the Holland and Lincoln Tunnels. Basic raw data will come from both induction-loop vehicle detectors and photocell vehicle detectors arranged in alternating pairs at seven points in each of the ten traffic lanes comprising the two facilities. Output will consist of control signals to entrance traffic devices, as well as alarms designed to draw the attention of facility personnel to one of nine or more television monitors per tube showing the area of a detected stoppage.
TL;DR: Some streets in the heart of Washington, D. C., are to become a test site for trying new traffic-control strategies, and traffic parameters compatible with existing surveillance equipment and suitable for traffic control and evaluation have been selected.
Abstract: Some streets in the heart of Washington, D. C., are to become a test site for trying new traffic-control strategies. Surveillance (detection of vehicle presence and estimation of traffic conditions from this information) is an important function of this test site. Traffic parameters compatible with existing surveillance equipment and suitable for traffic control and evaluation have been selected, and their characteristics analyzed. These parameters are volume, occupancy, and queue length. Of these, only queue length uses estimation of individual vehicle motion and therefore is characterized by the greatest uncertainty. Its potential usefulness, however, is great enough to warrant considerable analytical and experimental effort. Equipment required for the surveillance task includes the vehicle detectors, communications, and digital computer. Selection of the detector is influenced by local ordinances, as well as the system requirements; the result was the choice of an inductive loop detector. For the selection of the communications several techniques were compared, and a modified tone-multiplexing approach was chosen. The computer requirements for surveillance include handling high detector input rates, performing high-speed computation and bit manipulation, and providing disk and tape storage for the surveillance-derived data.
TL;DR: A review of proposed highway communication, surveillance, and control functions, indicates future requirement for a very substantial bandwidth in the radio-frequency spectrum, as well as the need for localization and directionalization of signaling fields to minimize interference difficulties.
Abstract: Problems are discussed that are presented by shortage of available radio channels if conventional space-wave propagation modes are to be utilized on any extensive basis in establishing new communication and control facilities on interstate highways to enhance safety and efficiency of operation. The need for an integrated-system approach to attain maximum efficiency in the use of the radio spectrum, and adaptability to orderly expansion by compatible stages in accommodating future functions such as those involved in the automatic-highway concept are emphasized. A review of proposed highway communication, surveillance, and control functions, indicates future requirement for a very substantial bandwidth in the radio-frequency spectrum, as well as the need for localization and directionalization of signaling fields to minimize interference difficulties. Use of coaxial-cable systems, with roadside transmission facilities positioned below ground level, is proposed in lieu of microwave or other radio-relay techniques for a number of point-to-point communication and control functions of value to the public and to highway departments. The technical aspects of these roadway services, as well as factors relating to utilization of induction-radio transmission methods as a means of restricting effective signaling range substantially within the right-of-way for vehicular communication functions are discussed. Field strength and other measurement data as derived from experimental tests of roadside-cable systems at various carrier frequencies are incorporated.
Journal Article•
TL;DR: VEHICLE-DETECTOR ACCURACY REQUIREments, INSTALLATION COST, LOCATION, and the ROADWAY ENVIRONMENT are used to develop a set of PREFERRED VEHicle-DetECTor CHARACTERISTICS to develop future non-cooperative vehicles.
Abstract: THREE DIFFERENT ELECTROMAGNETIC-LOOP VEHICLE-DETECTOR DESIGNS ARE DESCRIBED: SELF-TUNING, BRIDGE BALANCE, AND PHASE-SHIFT. PRINCIPLES OF OPERATION, DESIGN LIMITATIONS, AND DESIGN TRADEOFFS FOR EACH METHOD ARE PRESENTED IN DETAIL. VARIATIONS IN THE CHARACTERISTICS OF THE LEAD-IN WIRE ARE THE PRIMARY LIMITATION OF LOOP DETECTOR PERFORMANCE AND STABILITY. CHARACTERISTICS OF COMMERCIALLY AVAILABLE WIRE USED IN PRESENT-DAY LOOP DETECTOR INSTALLATIONS ARE DISCUSSED. DESIGN EQUATIONS AND GRAPHS ILLUSTRATE THE TRADEOFF CONSIDERATIONS IN THE DETERMINATION OF OPTIMUM LOOP CONFIGURATION AND INDUCTANCE. THREE DIFFERENT PHENOMENA ARE DISCUSSED AS APPLIED TO THE DETECTION OF ROADWAY VEHICULAR TRAFFIC. THESE DETECTORS ARE THE INPUT DATA SOURCE FOR VEHICLE-ACTUATED TRAFFIC SIGNAL LIGHT CONTROL MECHANISMS, CONTROL SYSTEMS, FREE-WAY SURVEILLANCE, AND STATISTICAL ANALYSIS. RADAR DETECTORS USING MICROWAVE RADIO FREQUENCIES IN THE 2.5-10 MHZ ARE DISCUSSED WITH REGARD TO OPERATING PRINCIPLES, DESIGN CONSIDERATION, AND PRATICAL APPLICATION. SIMILARLY, ACOUSTICAL DETECTORS OPERATING IN THE 20 KHZ RANGE AND LOW-FLUX DENSITY CHANGE MAGNETIC DETECTORS ARE DISCUSSED. A COMPARATIVE ANALYSIS IS MADE OF RADAR, ACOUSTICAL, AND MAGNETIC DETECTORS, AS WELL AS MECHANICAL, MAGNETIC, INDUCTION, AND OPTICAL DETECTORS. THIS PAPER PRESENTS SOME OF THE ECONOMIC AND TECHNICAL CONSIDERATIONS FOR DEVELOPMENT OF FUTURE NONCOOPERATIVE VEHICLE-DETECTOR SYSTEMS. VEHICLE-DETECTOR ACCURACY REQUIREMENTS, INSTALLATION COST, LOCATION, AND THE ROADWAY ENVIRONMENT ARE USED TO DEVELOP A SET OF PREFERRED VEHICLE-DETECTOR CHARACTERISTICS. IN ADDITION, A DESCRIPTION OF VEHICLE DETECTORS, CONSIDERED FOR DEVELOPMENT BY THE BUREAU OF PUBLIC ROADS, AND SOME OF THE CURRENT VEHICLE-DETECTOR CONCEPTS UNDER DEVELOPMENT, ARE PRESENTED, VIZ., INDUCTION COIL DETECTOR (SENSES ELECTRICAL NOISE GENERATED BY THE VEHICLE) FIELD ASYMMETRY SENSING TECHNIQUE (USES TWO ORTHOGONAL COILS), AND RF DETECTOR (AIMS A RADAR BEAM AT THE UNDERSIDE OF A CAR). /AUTHOR/
TL;DR: The title "New Challenges for Vehicular Technology mineering" aptly describes the technical program of the Twentieth Annual Conference, which was held on December 4-5, 1969, in Columbus. OH, USA as discussed by the authors.
Abstract: The title "New Challenges for Vehicular Technology mineering" aptly describes the technical program of the Twentieth Annual Conference, which was held on December 4-5, 1969, in Columbus. OH, USA. The Conference Committee concluded that, while the IEEE Vehicular Technology Group had established strength in certain areas (e.g. mobile communications), the Twentieth Annual Conference presented an excellent opportunity to expand in several new and important directions. The resulting program, whicn is shown herein, thus represents an attempt by the Committee to stimulate interest in these new areas without diminishing interest and quality in our traditional areas of strength.