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Publication Number: FHWA-HRT-06-139
Date: October 2006

Traffic Detector Handbook:Third Edition—Volume II

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Research, Development, and Technology
Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, VA 22101-2296


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FOREWORD

The objective of the third edition of the Traffic Detector Handbook is to provide a comprehensive reference document to aid the practicing traffic engineer, planner, or technician in selecting, designing, installing, and maintaining traffic sensors for signalized intersections and freeways. Judicious application of the concepts and procedures set forth in the Handbook should result in improved installations and operations of traffic sensors and a long-term savings of public funds.

Sensor types include both in-roadway and over-roadway sensors. Topics covered include sensor technology, sensor applications, in-roadway sensor design, sensor installation techniques and sensor maintenance. The sensor technology chapter discusses the operation and uses of inductive loop detectors, magnetic sensors and detectors, video image processors, microwave radar sensors, laser radars, passive infrared and passive acoustic array sensors, and ultrasonic sensors, plus combinations of sensor technologies. Sensor application topics include safety, operation, multimodal issues, and physical and economic factors that affect installation and performance. The appendixes include a variety of research, background papers, and implementation guidance. The information contained in this Handbook is based on the latest research on available treatments and best practices in use by jurisdictions across the United States and elsewhere. References are provided for the student, practitioner, researcher, or decisionmaker who wishes to learn more about a particular subject.

The third edition is published in two volumes, of which this is the second, Volume II (FHWA-HRT-06-139), containing Chapters 5 and 6 and all Appendixes. Volume I (FHWA-HRT-06-108) contains Chapters 1 through 4.

Antoinette Wilbur, Director
Office of Operations
Research and Development

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

QUALITY ASSURANCE STATEMENT

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Technical Report Documentation Page

1. Report No.
FHWA-HRT-06-139
2. Government Accession No.3. Recipient’s Catalog No.
4. Title and Subtitle
Traffic Detector Handbook: Third Edition–Volume II
5. Report Date
October 2006
6. Performing Organization Code
7.Author(s)
Principal Author: Lawrence A. Klein
Coauthors: Milton K. Mills, David R.P. Gibson
8. Performing Organization Report No.
 
9. Performing Organization Name and Address
Lawrence A. Klein
3 Via San Remo
Rancho Palos Verdes, CA 90275
10. Work Unit No. (TRAIS)
11. Contract or Grant No.
Contract No. DTFH61-03-P00317
12. Sponsoring Agency Name and Address
12. Sponsoring Agency Name and Address
Federal Highway Administration
Turner-Fairbank Highway Research Center
6300 Georgetown Pike, HRDO-04, Room No. T204
McLean, VA 22101-2296
13. Type of Report and Period Covered
Implementation Package
14. Sponsoring Agency’s Code
15. Supplementary Notes
David R.P. Gibson (David.Gibson@fhwa.dot.gov) at the Turner-Fairbank Highway Research Center (http://www.fhwa.dot.gov/research/tfhrc/) was the Technical Representative for the Federal Highway Administration (FHWA). Milton K. Mills, Advanced Research Team FHWA, contributed many technical papers. Traffic sensor researchers and practitioners contributed significantly to document organization, content, and exhibits. The peer review panel, consisting of Darcy Bullock of Purdue University, Dan Middleton of Texas Transportation Institute, and Tom Urbanik of the University of Tennessee, provided peer review and advice based on their use and testing of sensors. Tom Potter of Reno A&E gave technical advice on the electrical functioning of loop detectors. Sensor vendors provided technical information and exhibits on their technologies. In addition, many FHWA staff members participated as sensor group members and/or provided comments throughout the project, including Pamela Crenshaw, Ralph Gillman, Peter Huang, David Jones, and Raj Ghaman.
16. Abstract
The objective of this Handbook is to provide a comprehensive resource for selecting, designing, installing, and maintaining traffic sensors for signalized intersections and freeways. It is intended for use by traffic engineers and technicians having responsibility for traffic sensors, whether in-roadway or over-roadway sensors. These two families of sensors have different characteristics and thus corresponding advantages and disadvantages that are discussed throughout the Handbook. Topics covered include sensor technology, applications, in-roadway sensor design, installation techniques, and maintenance. The sensor technology chapter discusses the operation and uses of inductive loop detectors, magnetic sensors and detectors, video image processors, microwave radar sensors, laser radars, passive infrared and passive acoustic array sensors, and ultrasonic sensors, plus combinations of sensor technologies. The sensor application topics addresses safety, operational performance, multimodal issues, and physical and economic factors that the practitioner should consider. Appendixes include research, background papers, and implementation guidance. The information contained in this Handbook is based on the latest research available on treatments and best practices in use by the surveyed jurisdictions. References are provided for the student, practitioner, researcher, or decisionmaker who wishes to learn more about a particular subject.

The third edition is published in two volumes, of which this is the second, Volume II (FHWA-HRT-06-139), containing Chapters 5 and 6 and all Appendixes. Volume I (FHWA-HRT-06-108) contains Chapters 1 through 4.
17. Key Words
Traffic detectors, sensors, detector installation, detector maintenance, signalized intersections, intersection safety, intersection treatments, infrared sensor, inductive loop, magnetometer, video image processor, microwave radar sensor, laser radar sensor, acoustic sensor, ultrasonic sensor, magnetic sensor.
18. Distribution Statement
No restrictions. This document is available to the public through the National Information Technical Service, Springfield, VA, 22161 and Research and Technology Product Distribution Center, 9701 Philadelphia Court, Unit Q, Lanham, MD 20706; telephone: 301–577–0818; fax: 301–577–1421.
19. Security Classif. (of this report)
Unclassified
20. Security Classif. (of this page)
Unclassified
21. No. of Pages
394
22. Price
Form DOT F 1700.7 (8-72)Reproduction of completed page authorized.

SI* (Modern Metric) Conversion Factors


CONTENTS OF VOLUME I

Chapter 1. Introduction

  1. SCOPE AND OBJECTIVES OF THE HANDBOOK
  2. THE NEED FOR SENSORS IN MODERN TRAFFIC MANAGEMENT SYSTEMS
  3. EVOLUTION OF TRAFFIC FLOW SENSOR TECHNOLOGY
  4. NEED FOR SENSOR ALTERNATIVES
  5. SENSOR TECHNOLOGY CHARACTERISTICS
  6. MODERN VEHICLE SENSORS
  7. DEFINITION OF TERMS
  8. ORGANIZATION OF HANDBOOK
  9. REFERENCES

Chapter 2. Sensor Technology

  1. INDUCTIVE LOOP DETECTORS
  2. THEORY OF OPERATION
  3. LOOP CHARACTERISTICS
  4. CALCULATING INDUCTANCE
  5. TEMPORARY LOOPS
  6. ELECTRONICS UNITS
  7. MAGNETIC SENSORS
  8. THEORY OF OPERATION
  9. TWO-AXIS FLUXGATE MAGNETOMETERS
  10. MAGNETIC DETECTORS
  11. THEORY OF OPERATION
  12. VIDEO IMAGE PROCESSORS
  13. MICROWAVE RADAR SENSORS
  14. LASER RADARS
  15. PASSIVE INFRARED SENSORS
  16. ULTRASONIC SENSORS
  17. PASSIVE ACOUSTIC ARRAY SENSORS
  18. SENSOR COMBINATIONS
  19. REFERENCES

Chapter 3. Sensor Applications

  1. PRESENCE AND PASSAGE SENSORS
  2. SPEED MONITORING WITH INDUCTIVE LOOP AND OTHER POINT SENSORS
  3. TRAFFIC MANAGEMENT CONCEPTS FOR FREEWAYS
  4. SIGNAL CONTROL CONCEPTS FOR CITY STREETS
  5. SYSTEMS ENGINEERING PROCESS IN DESIGN OF TRAFFIC SIGNAL SYSTEMS
  6. FREEWAY SURVEILLANCE AND CONTROL
  7. COORDINATED OPERATION OF FREEWAYS AND SURFACE ARTERIALS
  8. TRAFFIC DATA COLLECTION
  9. DETECTION OF PRIORITY VEHICLES
  10. PEDESTRIAN DETECTION AND SIGNAL ACTUATION
  11. DRIVER WARNING FOR RED SIGNAL AHEAD
  12. TRAFFIC COUNTING AND VEHICLE CLASSIFICATION
  13. OVERHEIGHT SENSORS
  14. WEATHER SENSORS
  15. VEHICLE-MOUNTED SENSORS THAT ENHANCE SAFE OPERATION
  16. IN-VEHICLE SENSORS FOR DISTANCE WARNING, CRUISE CONTROL, AUTOMATIC HIGHWAY SYSTEM FUNCTIONS, AND PRECRASH DETECTION
  17. IN-VEHICLE OPTICAL SENSORS FOR PASSENGER DETECTION, VISION ENHANCEMENT, AND LANE CONTROL
  18. REFERENCES

Chapter 4. In-Roadway Sensor Design

  1. SELECTION CRITERIA
  2. DESIGN CONSIDERATIONS
  3. LOW-SPEED APPROACHES
  4. REST-IN-RED SPEED CONTROL
  5. INDUCTIVE LOOP DETECTOR DESIGN ALTERNATIVES
  6. SPECIAL FUNCTION APPLICATIONS
  7. DETECTION OF LONG, HIGH-BED VEHICLES
  8. QUEUE DETECTION
  9. INDUCTIVE-LOOP DETECTOR DESIGN FOR TRAFFIC SIGNAL CONTROL SYSTEMS
  10. INDUCTIVE-LOOP DETECTOR ELECTRONICS UNITS
  11. MAGNETOMETER CONFIGURATIONS
  12. MAGNETIC-DETECTOR CONFIGURATION
  13. REFERENCES

CONTENTS OF VOLUME II

CHAPTER 5. SENSOR-INSTALLATION TECHNIQUES
     TYPICAL PREINSTALLATION ACTIVITIES
          SCALE DRAWING OF SENSOR INSTALLATION SITE
          FIELD VISITS
          INSTALLATION CREW ESTIMATES
          EQUIPMENT REQUIREMENTS
          MATERIAL REQUIREMENTS
     INDUCTIVE-LOOP DETECTOR INSTALLATION
          INSTALLATION TECHNIQUES
          INDUCTIVE-LOOP DETECTOR FAILURES
               Causes of Inductive-Loop Detector Failures
               Failure Frequency
               Failure Mechanisms
          LOOP LAYOUT AND SAWCUTS
               Corner Treatment
               Saw-Cutting Operations
                    Overview of Saw-Cutting Equipment
                    Diamond-Blade Design
                    Saw-Blade Troubleshooting
                    Saw Horsepower
                    Wet Versus Dry Cutting
                    Sawcut Depth
                    Finishing the Sawcut
          INSTALLING LOOP WIRE
               Wire Type
                    Ducted Wire
                    Prewound Loops
                    Preformed Loops
                    Metal-Sheathed Loop Cable
               Wire Insertion
          CROSSING PAVEMENT JOINTS
          TWISTING THE LOOP WIRE LEAD-IN
          CROSSING CURBS
          INSTALLATION OF PULL BOX AND CONDUIT
          TESTING THE LOOP
          SEALING THE SAWCUT
               Types of Sealants
               Sealant Application Techniques
          SPLICING THE WIRE
               Connecting the Wires
               Sealing the Splice from the Operating Environment
          LEAD-IN CABLE INSTALLATION
          FINAL TESTS AND RECORD KEEPING
          GENERAL INSTALLATION GUIDELINES
     INDUCTIVE-LOOP DETECTOR INSTALLATION ALTERNATIVES
          SLAB LOOPS
          ROUND LOOPS
               Round-Loop Installation in Roadways
               Round-Loop Installation on Sidewalks
     INSTALLATION OF TWO-AXIS FLUXGATE MAGNETOMETERS
          INSTALLATION OF SENSING PROBE
          SPLICING THE CABLES
          TESTING THE SYSTEM
          SEALING THE HOLES AND CUTS
     INSTALLATION OF MAGNETIC DETECTORS
          INSTALLATION PROCEDURE
          TRENCHING
          CONNECTING THE SYSTEM
          TESTING THE SYSTEM
     OVER-ROADWAY SENSOR INSTALLATION
          INITIAL SENSOR EVALUATIONS
     VIDEO IMAGE PROCESSORS
          SITE SURVEYS
          LENS SELECTION
          CALIBRATION ISSUES
          SERIAL DATA INTERPRETATION SOFTWARE
          AUTOSCOPE 2004 VIDEO IMAGE PROCESSOR DETECTION ZONES
          TRAFICON VIP2 VIDEO IMAGE PROCESSOR DETECTION ZONES
     MICROWAVE RADAR SENSORS
          WHELEN TDN-30 CW DOPPLER SENSOR
          MICROWAVE SENSORS TC-20 CW DOPPLER SENSOR
          EIS RTMS FMCW RADAR
          ACCUWAVE 150LX FMCW RADAR
     LASER RADAR SENSORS
     PASSIVE INFRARED SENSORS
     ULTRASONIC SENSORS
     PASSIVE ACOUSTIC SENSORS
          IRD SMARTSONIC SINGLE-LANE ACOUSTIC SENSOR
          SMARTEK SAS-1 MULTIPLE-LANE ACOUSTIC SENSOR
     SENSOR COMBINATIONS
     REFERENCES

CHAPTER 6. SENSOR MAINTENANCE
     NATURE OF THE PROBLEM
     FAILURE MODES IN INDUCTIVE-LOOP DETECTOR SYSTEMS
          FAILURE MECHANISMS
               Omitted Phase
               Stuck Signal
               Phase Extending to Maximum
               Intermittent Problems
               Crosstalk
               Splashover
          CAUSES OF LOOP SYSTEM FAILURE
          FACTORS AFFECTING REQUIRED MAINTENANCE
     TROUBLESHOOTING PROCEDURES FOR INDUCTIVE-LOOP DETECTORS
          SAWCUT MAINTENANCE
          REARRANGEMENT OF LOOP CONNECTIONS
          ELIMINATING CROSSTALK
          SUBSTITUTION OF ELECTRONICS UNITS
          OPERATIONAL CHECK OF MALFUNCTIONING INDUCTIVE-LOOP DETECTOR
               Adjacent Lane Detection
               Intermittent Operation
               System Sensitivity
          ELECTRICAL TESTING OF AN INDUCTIVE-LOOP DETECTOR SYSTEM
          TEST PROCEDURES
               Sequential Test Procedure
                    Step 1. Conduct Visual Inspection
                    Step 2. Check Operation of Inductive-Loop Electronics Unit
                    Step 3. Measure Parameters Needed To Determine Quality Factor Q
                    Step 4. Determine Q
                    Step 5. Measure Sensitivity of Inductive-Loop System
                         Method 1
                         Method 2
                    Step 6. Analysis
     MAGNETOMETER SYSTEM MAINTENANCE
          CAUSES OF MAGNETOMETER FAILURES.6-17
               Probe Burial Depth
               Probe Movement
               Probe Cable
               Sawcut Maintenance
          TROUBLESHOOTING PROCEDURES
     MAGNETIC DETECTOR MAINTENANCE
     OVER-ROADWAY SENSOR MAINTENANCE
          VIDEO IMAGE PROCESSORS
          MICROWAVE RADAR SENSORS
     MAINTENANCE COST COMPARISONS AMONG SENSOR TECHNOLOGIES
     REFERENCES

APPENDIX A. INDUCTIVE-LOOP SYSTEM EQUIVALENT CIRCUIT MODEL
     ABSTRACT
     INTRODUCTION
     LOOP CAPACITANCE THEORY
          INTERNAL-LOOP CAPACITANCE
          EXTERNAL-LOOP CAPACITANCE
     LOOP RESISTANCE THEORY
          LOOP RESISTANCE
          INTERNAL INDUCTANCE AND RESISTANCE PER UNIT LENGTH FOR A CYLINDRICAL CONDUCTOR
     LOOP-INDUCTANCE THEORY
          SELF-INDUCTANCE OF SINGLE-TURN CIRCULAR LOOP
          SELF-INDUCTANCE OF MULTITURN CIRCULAR LOOP
          EXTERNAL INDUCTANCE OF SINGLE-TURN RECTANGULAR LOOP
          SELF-INDUCTANCE OF SINGLE-TURN RECTANGULAR LOOP
          SELF-INDUCTANCE OF MULTITURN RECTANGULAR LOOP
          MUTUAL INDUCTANCE OF PARALLEL FILAMENTARY CIRCUITS
          MUTUAL INDUCTANCE OF TWO COAXIAL AND PARALLEL RECTANGULAR LOOPS
          SELF-INDUCTANCE OF MULTITURN QUADRUPOLE LOOP
          GENERAL FORMULA FOR MUTUAL INDUCTANCE OF PARALLEL FILAMENTS
          INDUCTIVE-LOOP CIRCUIT MODEL
     LOOP TRANSMISSION LINE THEORY
          LOOP TRANSMISSION LINE MODEL
          FREQUENCY SHIFT ELECTRONICS UNIT SENSITIVITY
     LOOP TRANSFORMER THEORY
          INDUCTIVE-LOOP TRANSFORMER MODEL
     LOOP-DETECTOR ANALYSIS SYSTEM PROGRAM
     COMPARISON OF CALCULATED AND MEASURED LOOP SELF-INDUCTANCE AND QUALITY FACTOR
          CONCLUSIONS
     APPENDIX A-1
          LOOP GROUND-RESISTANCE DERIVATION
     APPENDIX A-2
          REAL PART OF COMPLEX BESSEL FUNCTION OF FIRST KIND
          DERIVATIVE OF REAL PART
          IMAGINARY PART OF COMPLEX BESSEL FUNCTION OF FIRST KIND
          DERIVATIVE OF IMAGINARY PART
     APPENDIX A-3
          COMPLETE ELLIPTIC INTEGRAL OF FIRST KIND
          COMPLETE ELLIPTIC INTEGRAL OF SECOND KIND
     APPENDIX A-4
          SERIES TO PARALLEL CIRCUIT TRANSFORMATION
     APPENDIX A-5
          TRANSFORMER MODEL INPUT IMPEDANCE
     REFERENCES

APPENDIX B. CURRENT SHEET FORMULA FOR CALCULATION OF LOOP INDUCTANCE
     SAMPLE INDUCTANCE CALCULATION
     REFERENCES

APPENDIX C. LOOP INDUCTANCE AND QUALITY FACTOR TABLES
     ABSTRACT

APPENDIX D. ELECTRICAL CHARACTERISTICS OF WIRE AND CABLE
     CAPACITANCE OF PARALLEL CONDUCTORS
     INDUCTANCE OF PARALLEL CONDUCTORS

APPENDIX E. VEHICLE DETECTION SENSITIVITY FORMULAS FOR RECTANGULAR LOOPS
     ABSTRACT
     INTRODUCTION
     VEHICLE DETECTION SENSITIVITY THEORY
          VEHICLE MODEL
          REINFORCING STEEL MODEL
          CIRCUIT MODEL FOR ONE-TURN LOOP
               Circuit Equations for One-Turn Loop
               Inductive-Loop Driving-Point Impedance
               Inductive-Loop Sensitivity
          CIRCUIT MODEL FOR TWO-TURN LOOP
               Circuit Equations for Two-Turn Loop
          CIRCUIT EQUATIONS FOR MULTITURN LOOP
          VEHICLE DETECTION SENSITIVITY FOR A MULTITURN LOOP
          INDUCTIVE-LOOP DETECTOR SENSITIVITY
     LOOP-DETECTOR SENSITIVITY MEASURED DATA AND CALCULATED RESULTS
          LOOP-DETECTOR SENSITIVITY COMPUTER PROGRAM
          MEASURED-LOOP DETECTOR SENSITIVITY DATA
          COMPARISON BETWEEN MEASURED AND CALCULATED SENSITIVITY DATA
          EFFECT OF LOOP TURNS ON SENSITIVITY
          EFFECT OF LOOP VOLUME ON SENSITIVITY
          EFFECT OF LEAD-IN CABLE INDUCTANCE ON SENSITIVITY
          EFFECT OF MESH ON SENSITIVITY
          EFFECT OF LEAD-IN CABLE AND MESH ON SENSITIVITY
     RESULTS AND CONCLUSIONS
     REFERENCES

APPENDIX F. DIGITAL FREQUENCY-SHIFT ELECTRONICS UNIT ANALYSIS
     ABSTRACT
     ANALYSIS

APPENDIX G. DIGITAL RATIOED FREQUENCY-SHIFT ELECTRONICS UNIT ANALYSIS
     ABSTRACT
     ANALYSIS

APPENDIX H. DIGITAL PERIOD-SHIFT ELECTRONICS UNIT ANALYSIS
     ABSTRACT
     ANALYSIS

APPENDIX I. DIGITAL RATIOED PERIOD-SHIFT ELECTRONICS UNIT ANALYSIS
     ABSTRACT
     ANALYSIS

APPENDIX J. NEMA DETECTOR STANDARDS EXCERPTS
     INTRODUCTION
     NEMA TS 1 AND TS 2 TRAFFIC CONTROL SYSTEMS
     DETECTOR TERMS AND DEFINITIONS
          1.2.4 DETECTION
               1.2.4.1 Advisory Detection
               1.2.4.2 Passage Detection
               1.2.4.3 Presence Detection
          1.2.5 DETECTOR
               1.2.5.1 Bidirectional Detector
               1.2.5.2 Calling Detector
               1.2.5.3 Classification Detector
               1.2.5.4 Directional Detector
               1.2.5.5 Extension Detector
               1.2.5.6 Infrared Detector
               1.2.5.7 Light-Sensitive Detector
               1.2.5.8 Loop Detector
               1.2.5.9 Magnetic Detector
               1.2.5.10 Magnetometer Detector
               1.2.5.11 Nondirectional Detector
               1.2.5.12 Pedestrian Detector
               1.2.5.13 Pneumatic Detector
               1.2.5.14 Pressure-Sensitive Detector
               1.2.5.15 Radar Detector
               1.2.5.16 System Detector
               1.2.5.17 Side-Fire Detector
               1.2.5.18 Sound-Sensitive Vehicle Detector
               1.2.5.19 Ultrasonic Detector
          1.2.6 DETECTOR MODE
          1.2.7 INDUCTIVE LOOP DETECTOR SYSTEM
          1.2.8 INDUCTIVE LOOP DETECTOR UNIT
          1.2.9 LEAD-IN CABLE
          1.2.10 OUTPUT
               1.2.10.1 Extension Output
               1.2.10.2 Delayed Output
          1.2.11 PROBE
          1.2.12 SENSOR
          1.2.13 VEHICLE DETECTOR SYSTEM
          1.2.14 ZONE OF DETECTION (SENSING ZONE)
     ENVIRONMENTAL TESTING OF DETECTORS
          2.8 LOOP DETECTOR UNIT TESTS
               2.8.1 Environmental Requirements
                    2.8.1.1 Voltage, DC Supply
                    2.8.1.2 Temperature and Humidity
                    2.8.1.3 Transients, DC Powered Units
                    2.8.1.4 Transients, Loop Detector Input Terminals
                    2.8.1.5 Vibration
                    2.8.1.6 Shock
     MINIMUM REQUIREMENTS FOR DETECTORS
          6.5 INDUCTIVE LOOP DETECTOR UNITS
               6.5.1 Loop Detector Unit Definitions
                    6.5.1.1 Channel
                    6.5.1.2 Crosstalk
                    6.5.1.3 Detector Mode
                    6.5.1.4 Lead-In Cable
                    6.5.1.5 Loop Detector System
                    6.5.1.6 Loop Detector Unit
                    6.5.1.7 Reset Channel
                    6.5.1.8 Reset Unit
                    6.5.1.9 Sensor Loop
                    6.5.1.9 Vehicle Detector System
                    6.5.1.9 Zone of Detection
               6.5.2 Functional Standards
                    6.5.2.1 Operation
                    6.5.2.2 Configurations and Dimensions
                         6.5.2.2.1 Configurations
                         6.5.2.2.2 Dimensions
                    6.5.2.3 Accessibility
                    6.5.2.4 Material and Construction of Rigid Printed Circuit Assemblies
                         6.5.2.4.1 Materials
                         6.5.2.4.2 Component Identification
                    6.5.2.5 Power Inputs
                         6.5.2.5.2 Low Supply Voltage Automatic Reset
                    6.5.2.6 Logic Ground
                    6.5.2.7 Earth Ground
                         6.5.2.8.1 Low or Active State
                         6.5.2.8.2 High or Inactive State
                         6.5.2.8.3 Transition Voltage Zone Of Input Circuitry
                         6.5.2.8.4 External Transition Time
                         6.5.2.8.5 Maximum Current
                         6.5.2.8.6 Signal Recognition
                         6.5.2.8.7 Activation of Delay/Extension Feature
                         6.5.2.8.8 Activation of Detector Unit Address Feature
                         6.5.2.9 Data Receive (RX) Input
                         6.5.2.9.1 Mark State (Binary 1)
                         6.5.2.9.2 Space State (Binary 0)
                         6.5.2.9.3 Other States
                         6.5.2.9.4 Transient Withstand
                    6.5.2.10 Loop Inputs
                    6.5.2.11 Loop/Lead in Electrical Properties
                    6.5.2.12Test Loop Configurations
                    6.5.2.13 Test Vehicle Definition
                    6.5.2.14 Sensitivity
                    6.5.2.15 Sensitivity Control
                    6.5.2.16 Approach Speed
                    6.5.2.17 Modes of Operation
                         6.5.2.17.1 Presence
                         6.5.2.17.2 Pulse
                    6.5.2.18 Recovery from Sustained Occupancy
                    6.5.2.19 Response Time
                         6.5.2.19.1 Variation in Response Time
                    6.5.2.20 Tuning
                    6.5.2.21 Self-Tracking
                    6.5.2.22 Recovery From Reset
                    6.5.2.23 Crosstalk Avoidance
                    6.5.2.24 Delay/Extension
                         6.5.2.24.1 Delay
                         6.5.2.24.2 Extension
                    6.5.2.25 Controls and Indicators
                    6.5.2.26 Outputs
                         6.5.2.26.1 Solid State Channel Detection Outputs
                         6.5.2.26.2 Channel Status Outputs
                         6.5.2.26.3 Channel Status Reporting
                         6.5.2.26.4 Data Transmit Output (TX)
                              6.5.2.26.4.1 Mark State (Binary 1)
                              6.5.2.26.4.2 Space State (Binary 0)
                              6.5.2.26.4.3 High Impedance State
                              6.5.2.26.4.4 Output Impedance During Power Off
                              6.5.2.26.4.5 TX Output Shorts
                              6.5.2.26.4.6 Rise/Fall Time
                              6.5.2.26.4.7 Transient Withstand
                    6.5.2.27 Communication Port Functional Requirements
                         6.5.2.27.1 Communication Port Electrical Requirements
                         6.5.2.27.2 Baud Rate
                         6.5.2.27.3 Communication Parameters
                         6.5.2.27.4 Slot Addresses
                    6.5.2.28 Electrical Connections
                         6.5.2.28.1 Connector Description
                         6.5.2.28.2 Connector Terminations
                         6.5.2.28.3 Type A Two Channel Without Delay / Extension Timing
                         6.5.2.28.4 Type B Four Channel Without Delay / Extension Timing
                         6.5.2.28.4 Type C Two Channel With Delay / Extension Timing
     REFERENCES

APPENDIX K. CALTRANS TRANSPORTATION ELECTRICAL EQUIPMENT SPECIFICATIONS (TEES) FOR ELECTRONICS UNITS AND MAGNETIC DETECTORS
     SECTION 1. GENERAL REQUIREMENTS
          5.1.1 CHANNEL INDEPENDENCE AND POWER REQUIREMENTS
          5.1.2 SENSOR UNIT FEATURES
          5.1.3 OUTPUT DEVICE TYPE
          5.1.4 OUTPUT SIGNAL CHARACTERISTICS
          5.1.5 INTERFACE REQUIREMENTS
          5.1.6 OUTPUT DEVICE SWITCHING TIME
          5.1.7 SERIAL OUTPUT DEFINITION
          5.1.8 ELECTRICAL SURGE PROTECTION
     SECTION 2. MODEL 222E AND 224E LOOP DETECTOR SENSOR UNIT REQUIREMENTS
          5.2.1 OUTPUT SIGNAL DEFINITION
          5.2.2 MALFUNCTIONING LOOP SIGNAL DEFINITION
          5.2.3 SUPPORTED LOOP CONFIGURATIONS
          5.2.4 INDUCTANCE AND Q RANGE OF SUPPORTED LOOP AND LEAD-IN CABLE ASSEMBLIES
          5.2.5 TRANSFORMER ISOLATION OF LOOP INPUTS
          5.2.6 NUMBER OF SUPPORTED OPERATING FREQUENCIES
          5.2.7 DRIFT COMPENSATION OF TUNING CIRCUITS
          5.2.8 PULSE AND PRESENCE MODE SUPPORT
               5.2.8.1: Pulse Mode Description
               5.2.8.2: Presence Mode Description
          5.2.9 SENSITIVITY
          5.2.10 RESPONSE TIME
          5.2.11 NORMAL OPERATION TIME
          5.2.12 TRACKING RATE
          5.2.13 TRACKING RANGE
          5.2.14 TEMPERATURE CHANGE
     SECTION 3. MAGNETIC DETECTOR REQUIREMENTS
          5.3.1 MODEL 231E MAGNETIC DETECTOR SENSING ELEMENT
               5.3.1.1 Design Requirements
               5.3.1.2 DC Resistance
          5.3.2 MODEL 232E TWO CHANNEL MAGNETIC DETECTOR SENSING UNIT
               5.3.2.1 Output Signal Definition
     REFERENCES

APPENDIX L. CLASSIFICATION OF SENSOR SYSTEMS BY SENSOR DENSITY LEVEL
     ABSTRACT
     TERMINOLOGY
          UNCOORDINATED SIGNALS or UNCOORDINATED CONTROL
          TIME-BASED COORDINATION or TIME-BASED COORDINATED CONTROL
          INTERCONNECTED CONTROL
          TRAFFIC ADJUSTED CONTROL
          TRAFFIC RESPONSIVE CONTROL
          TRAFFIC ADAPTIVE CONTROL
     SENSOR WEB DENSITY LEVELS
          SENSOR WEB DENSITY LEVEL 0.0
          SENSOR WEB DENSITY LEVEL 0.5
          SENSOR WEB DENSITY LEVEL 1.0
          SENSOR WEB DENSITY LEVEL 1.5
          SENSOR WEB DENSITY LEVEL 2.0
          SENSOR WEB DENSITY LEVEL 2.5
          SENSOR WEB DENSITY LEVEL 3.0
          SENSOR WEB DENSITY LEVEL 3.5
          SENSOR WEB DENSITY LEVEL 4.0
     GENERAL OBSERVATIONS
     REFERENCES

APPENDIX M. EXTENT AND CAUSES OF INDUCTIVE-LOOP FAILURES
     STUDIES SUMMARIZED IN THIS APPENDIX
     OREGON STUDY
          OREGON SURVEY RESULTS
          OREGON CONCLUSIONS AND RECOMMENDATIONS
     WASHINGTON STUDY
          WASHINGTON SURVEY RESULTS
          WASHINGTON CONCLUSIONS AND RECOMMENDATIONS
     MINNESOTA STUDY
          MINNESOTA SURVEY RESULTS
          MINNESOTA CONCLUSIONS AND RECOMMENDATIONS
     NEW YORK STUDY
          NEW YORK SURVEY RESULTS
          NEW YORK CONCLUSIONS AND RECOMMENDATIONS

APPENDIX N. GROUNDING (DESIGN GUIDELINES)
     SECTION I—REASONS FOR GROUNDING
          1. SAFETY GROUNDING
          2. SYSTEM GROUNDING
          3. LIGHTNING DISCHARGE
     SECTION II—CALCULATION OF RESISTANCE TO GROUND
          1. GENERAL
          2. SOIL RESISTIVITY
          3. GROUND ELECTRODE RESISTANCE TO GROUND
               3.1 Ground Rods
               3.2 Pedestals
               3.3 Plate Electrodes
               3.4 Wire Grids
               3.5 Multiple Rods
               3.6 Combination Rod and Wire Grids
               3.7 Single Wire
               3.8 Summary of Calculations
               3.9 Application
               3.10 Problem Areas
               3.11 Application Guidelines
     SECTION III—EFFECTS OF LIGHTNING
          1. GENERAL
          2. DESIGN CRITERIA
          3. POWER SURGES
          4. OTHER SOURCES OF POSSIBLE DAMAGE
     SECTION IV—SUMMARY OF DESIGN GUIDELINES
          1. TRAFFIC SIGNAL SYSTEMS
     SECTION V—REFERENCES

APPENDIX O. GROUNDING (MAINTENANCE GUIDELINES)
     SECTION I—TRAFFIC SIGNAL GROUNDING
          1. HYDRO GROUNDS
          2. SERVICE GROUNDS
          3. CABINET GROUNDS
          4. SPECIAL SOIL CONDITIONS
          5. SYSTEM GROUND
          6. ROUTINE INSPECTION
          7. EMERGENCY INSPECTION
          8. MEASUREMENTS
          9. STEEL FOOTINGS
          10. GROUND RODS
          11. GOOD PRACTICE
     SECTION II—REFERENCES

APPENDIX P. GLOSSARY

APPENDIX Q. REGISTERED TRADEMARKS


Figures in Volume I

CHAPTER 1. INTRODUCTION

  1. Figure 1-1. Growth in highway miles traveled in the U.S.
  2. Figure 1-2. Freeway-to-freeway HOV bypass lane structure under construction at intersection of CA-57 and CA-91 freeways in Anaheim, CA.
  3. Figure 1-3. Inductive-loop detector system
  4. Figure 1-4. Inductive-loop installation example.
  5. Figure 1-5. Magnetic anomaly in the Earth's magnetic field induced by magnetic dipoles in a ferrous metal vehicle.
  6. Figure 1-6. Overhead camera mounting on a mast arm as typically used to provide imagery to a VIP for arterial signal control.
  7. Figure 1-7. Microwave radar operation.
  8. Figure 1-8. Mounting of presence-detecting microwave radar sensors for multilane vehicle detection and signal actuation at an intersection.
  9. Figure 1-9. Scanning infrared laser radar two-beam pattern across a traffic lane.
  10. Figure 1-10. 3-D laser radar range image of a van pulling a boat.

CHAPTER 2. SENSOR TECHNOLOGY

  1. Figure 2-1. Inductive-loop detector system (notional).
  2. Figure 2-2. Magnetic flux around loop.
  3. Figure 2-3. Magnetic flux for solenoid (coil).
  4. Figure 2-4. Capacitive coupling between the loop wires themselves and the sawcut slot sidewalls.
  5. Figure 2-5. Equivalent electrical circuit for an inductive loop with capacitive coupling to the sidewalls of a sawcut slot.
  6. Figure 2-6. Average values of loop inductance vs. measuring frequency for series, parallel, and series-parallel connections of 6- x 6-ft (1.8- x 1.8-m) inductive loops.
  7. Figure 2-7. Loop system quality factor sample calculation.
  8. Figure 2-8. Four 6- x 6-ft (1.8- x 1.8-m) three-turn loops connected in series, parallel, and series-parallel.
  9. Figure 2-9. Bicycle detection showing induced eddy currents.
  10. Figure 2-10. Vehicle undercarriage model.
  11. Figure 2-11. Calculated sensitivity of three-turn inductive loops as a function of vehicle undercarriage height.
  12. Figure 2-12. Calculated sensitivity of three-turn inductive loops with 200 ft (60 m) of lead-in cable as a function of vehicle undercarriage height.
  13. Figure 2-13. Calculated sensitivity of two-turn long inductive loops as a function of vehicle undercarriage height.
  14. Figure 2-14. Calculated sensitivity of 6- x 6-ft (1.8- x 1.8-m) inductive loop over reinforcing steel.
  15. Figure 2-15. Equivalent total inductance from two inductive loops in series.
  16. Figure 2-16. Equivalent total inductance from two inductive loops in parallel.
  17. Figure 2-17. Single inductive loop connected to a pull box and electronics unit.
  18. Figure 2-18. Equivalent single loop electrical circuit.
  19. Figure 2-19. Two inductive loops connected in series to a pull box and electronics unit.
  20. Figure 2-20. Equivalent electrical circuit for two loops connected in series to a pull box and electronics unit.
  21. Figure 2-21. Two inductive loops connected in parallel to a pull box and electronics unit.
  22. Figure 2-22. Equivalent electrical circuit for two loops connected in parallel to a pull box and electronics unit.
  23. Figure 2-23. Typical installation of mat-type temporary inductive loop detector.
  24. Figure 2-24. Five-layer temporary open loop detector configuration.
  25. Figure 2-25. Nevada portable open loop installation.
  26. Figure 2-26. Inductance change produced by a small motorcycle as a function of lead-in cable length for series, parallel, and series-parallel connections of four 6- x 6-ft loops.
  27. Figure 2-27. Measurement of inductive loop oscillation period by a reference clock.
  28. Figure 2-28. Model S-1500 inductive-loop vehicle classifier and speed sensor.
  29. Figure 2-29. Classes available from inductive-loop classifying sensor.
  30. Figure 2-30. Axle location and vehicle classification using an array of inductive loops.
  31. Figure 2-31. Shelf-mounted NEMA electronics unit.
  32. Figure 2-32. Two-channel card rack mounted electronics unit.
  33. Figure 2-33. Four-channel card rack mounted electronics unit.
  34. Figure 2-34. Delay operation.
  35. Figure 2-35. Extension operation.
  36. Figure 2-36. Model 170 controller.
  37. Figure 2-37. Type 170 cabinet layout (California).
  38. Figure 2-38. Model 2070 controller.
  39. Figure 2-39. Magnetic sensor installation.
  40. Figure 2-40. Earth's magnetic flux lines.
  41. Figure 2-41. Equatorial belt showing where Earth's magnetic field is too small for deployment of simple vertical axis magnetometers between 20 degrees north and 20 degrees south of the Equator.
  42. Figure 2-42. Distortion of Earth's quiescent magnetic field by a ferrous metal vehicle.
  43. Figure 2-43. Magnetometer sensor electrical circuit (notional).
  44. Figure 2-44. Magnetometer sensor probe and electronics unit equivalent electrical circuit.
  45. Figure 2-45. SPVD-2 magnetometer system.
  46. Figure 2-46. Groundhog magnetometer sensors.
  47. Figure 2-47. Magnetic probe detector.
  48. Figure 2-48. Microloop probes.
  49. Figure 2-49. Tripline video image processors.
  50. Figure 2-50. Closed-loop tracking video image processor.
  51. Figure 2-51. Video image processor installed in a roadside cabinet.
  52. Figure 2-52. Conceptual image processing for vehicle detection, classification, and tracking.
  53. Figure 2-53. Vehicle count comparison from four VIPs and inductive-loop detectors.
  54. Figure 2-54. VIP vehicle count errors under varying illumination conditions.
  55. Figure 2-55. Distinguishing between two closely spaced vehicles.
  56. Figure 2-56. Distance d along the roadway at which a VIP can distinguish vehicles.
  57. Figure 2-57. Constant frequency waveform.
  58. Figure 2-58. CW Doppler microwave radars.
  59. Figure 2-59. FMCW signal and radar processing as utilized to measure vehicle presence and speed.
  60. Figure 2-60. FMCW microwave radars.
  61. Figure 2-61. Laser radar beam geometry.
  62. Figure 2-62. Autosense II laser radar sensor.
  63. Figure 2-63. EFKON Traffic Observation Module (TOM) laser radar sensor.
  64. Figure 2-64. Active infrared sensor installed for transmitting traffic conditions to motorists.
  65. Figure 2-65. Visible spectrum CCD camera imagery of approaching traffic typical of dawn and dusk lighting.
  66. Figure 2-66. Passive infrared sensor.
  67. Figure 2-67. Emission and reflection of energy by vehicle and road surface.
  68. Figure 2-68. Multiple detection zone configuration in a passive infrared sensor.
  69. Figure 2-69. TC-30C ultrasonic range-measuring sensor.
  70. Figure 2-70. Mounting of ultrasonic range-measuring sensors.
  71. Figure 2-71. Speed-measuring RDU-101 Doppler ultrasonic sensor.
  72. Figure 2-72. Operation of range-measuring ultrasonic sensor.
  73. Figure 2-73. Acoustic array sensors.
  74. Figure 2-74. Passive infrared combination sensors.

CHAPTER 3. SENSOR APPLICATIONS

  1. Figure 3-1. Vehicle speed measurement using two inductive-loop detectors placed a known distance apart.
  2. Figure 3-2. Isolated intersection control.
  3. Figure 3-3. Data processing at an intersection with isolated intersection control.
  4. Figure 3-4. Placement of sensors for fully actuated intersection control.
  5. Figure 3-5. Arterial open network and surface street closed network traffic signal configurations typical of those found in interconnected intersection control.
  6. Figure 3-6. UTCS timing plan selection procedure.
  7. Figure 3-7. Traffic flow characteristics during an incident.
  8. Figure 3-8. Freeway incident detection scenario.
  9. Figure 3-9. Conceptual ramp metering sensor and roadway configurations.
  10. Figure 3-10. Conceptual coordinated traffic responsive ramp control system.
  11. Figure 3-11. Principles of SWARM 1 ramp metering algorithm.
  12. Figure 3-12. Mainline metering configuration on I-80 westbound crossing the San Francisco-Oakland Bay Bridge.
  13. Figure 3-13. Freeway mainline metering at El Cajon, CA.
  14. Figure 3-14. Freeway-to-freeway metering at the junction of the I-105 and I-605 freeways in Norwalk, CA.
  15. Figure 3-15. Warning sign alerting drivers to unsafe speed.
  16. Figure 3-16. Infrared beacon priority system.
  17. Figure 3-17. Transmitter mounted under a vehicle identifies it to a subsurface inductive-loop detector.
  18. Figure 3-18. Inductive loop detection system for transit vehicles.
  19. Figure 3-19. Representative vehicle signatures obtained from loops excited by high-frequency signals from specialized electronics units.
  20. Figure 3-20. Sound detection priority system for 4-way intersection control.
  21. Figure 3-21. Manually operated pedestrian push button.
  22. Figure 3-22. Interactive pedestrian push button.
  23. Figure 3-23. Countdown timer showing time remaining for pedestrian crossing.
  24. Figure 3-24. Audible pedestrian signal device.
  25. Figure 3-25. Pedestrian crossing safety devices.
  26. Figure 3-26. PREPARE TO STOP lighted sign.
  27. Figure 3-27. Three-loop layout for counts.
  28. Figure 3-28. Directional detection using point sensors.
  29. Figure 3-29. Overheight sensor configuration.
  30. Figure 3-30. Integrated weather information system.
  31. Figure 3-31. Weather imagery and data display.
  32. Figure 3-32. Autovue lane tracking sensor.
  33. Figure 3-33. Output voltage generated by passive lane positioning sensor.

CHAPTER 4. IN-ROADWAY SENSOR DESIGN

  1. Figure 4-1. Actuated controller green phase intervals.
  2. Figure 4-2. Variable initial NEMA timing for green signal phase.
  3. Figure 4-3. NEMA gap reduction procedure.
  4. Figure 4-4. Intersection configured for loop occupancy control.
  5. Figure 4-5. Inductive loop detector length for loop occupancy control.
  6. Figure 4-6. Dilemma zone for vehicle approaching an intersection at 40 mi/h (64 km/h).
  7. Figure 4-7. PREPARE TO STOP sign on an arterial in nonilluminated and illuminated states.
  8. Figure 4-8. PREPARE TO STOP inductive-loop detector system.
  9. Figure 4-9. Small loop shapes.
  10. Figure 4-10. Caltrans-specified loop shapes.
  11. Figure 4-11. Long loop shapes.
  12. Figure 4-12. Caltrans standard sequential inductive loop configurations.
  13. Figure 4-13. PennDOT short inductive loop configurations.
  14. Figure 4-14. Wide inductive-loop detector layout.
  15. Figure 4-15. Left turn detection inductive loop configuration used by IDOT.
  16. Figure 4-16. "Cannot Stop" and "Cannot Go" regions.
  17. Figure 4-17. Dilemma zone (Xs Xc).
  18. Figure 4-18. Dilemma zone removal (Xs = Xc).
  19. Figure 4-19. Optional zone creation (Xs Xc).
  20. Figure 4-20. Green extension system using two inductive-loop detectors.
  21. Figure 4-21. Extended call inductive-loop detector system.
  22. Figure 4-22. Multiple inductive-loop detector placement (TxDOT) for alleviating the effects of dilemma zones.
  23. Figure 4-23. Quadrupole loop configuration.
  24. Figure 4-24. Bicycle sensor sign and markings used in Clarke County, GA.
  25. Figure 4-25. Special bicycle pavement marking used in San Luis Obispo, CA.
  26. Figure 4-26. Chevron loop configuration.
  27. Figure 4-27. Long loop with powerhead.
  28. Figure 4-28. Type D loop configuration (Caltrans).
  29. Figure 4-29. Type D loop installation.
  30. Figure 4-30. Wide coverage bicycle loop.
  31. Figure 4-31. Bicycle lane loop layout with side-by-side quadrupoles.
  32. Figure 4-32. Queue discharge system.
  33. Figure 4-33. Conceptual magnetometer sensor installation.
  34. Figure 4-34. Typical installation of magnetometers on a bridge deck.
  35. Figure 4-35. Magnetic field analyzer.
  36. Figure 4-36. Magnetometer probe placement in support of several data gathering functions.
  37. Figure 4-37. Setback of magnetic probe from stopline as a function of vehicle speed and allowable gap.
  38. Figure 4-38. Magnetic probe placement for a single-lane and two-lane approach to a stopline.
Figures in Volume II

CHAPTER 5. SENSOR INSTALLATION TECHNIQUES

CHAPTER 6. SENSOR MAINTENANCE

APPENDIX A. INDUCTIVE-LOOP SYSTEM EQUIVALENT CIRCUIT MODEL

APPENDIX D. ELECTRICAL CHARACTERISTICS OF WIRE AND CABLE

APPENDIX E. VEHICLE DETECTION SENSITIVITY FORMULAS FOR RECTANGULAR LOOPS

APPENDIX F. DIGITAL FREQUENCY-SHIFT ELECTRONICS UNIT ANALYSIS

APPENDIX G. DIGITAL RATIOED FREQUENCY-SHIFT ELECTRONICS UNIT ANALYSIS

APPENDIX H. DIGITAL PERIOD SHIFT ELECTRONICS UNIT ANALYSIS

APPENDIX I. DIGITAL RATIOED PERIOD-SHIFT ELECTRONICS UNIT ANALYSIS

APPENDIX J. NEMA STANDARDS

APPENDIX L. CLASSIFICATION OF SENSOR SYSTEMS BY SENSOR DENSITY LEVEL

APPENDIX M. EXTENT AND CAUSES OF INDUCTIVE-LOOP FAILURES

APPENDIX N. GROUNDING (DESIGN GUIDELINES)

APPENDIX O. GROUNDING (MAINTENANCE GUIDELINES)

TABLES IN VOLUME I

CHAPTER 1. INTRODUCTION

  1. Table 1-1. Strengths and weaknesses of commercially available sensor technologies.
  2. Table 1-2. Traffic output data (typical), communications bandwidth, and cost of commercially available sensors.

CHAPTER 2. SENSOR TECHNOLOGY

  1. Table 2-1. Resistance of cables commonly found in inductive-loop detector systems.
  2. Table 2-2. Rectangular loop inductance and quality factor parameters at f = 20 kHz.
  3. Table 2-3. Quadrupole loop inductance and quality factor parameters at f = 20 kHz.
  4. Table 2-4. Circular loop inductance and quality factor parameters at f = 20 kHz.
  5. Table 2-5. Twisted loop lead-in wire specifications.
  6. Table 2-6. Commercial lead-in cable specifications.
  7. Table 2-7. Influence of lead-in cable type and length on Q.
  8. Table 2-8. Influence of reinforcing steel on loop inductance (muH).
  9. Table 2-9. Comparison of sensitivities and response times of digital electronics units.
  10. Table 2-10. 2070 ATC module options.
  11. Table 2-11. 2070 ATC ITS cabinet options.
  12. Table 2-12. 2070 ATC models and cabinet options.
  13. Table 2-13. 2070 ATC modules corresponding to model and cabinet options.
  14. Table 2-14. Performance comparison of a visible spectrum video image processor using upstream and downstream viewing.

CHAPTER 3. SENSOR APPLICATIONS

  1. Table 3-1. Categories of traffic signal systems and their characteristics or requirements.
  2. Table 3-2. Local responsive ramp metering rates based on mainline occupancy.
  3. Table 3-3. Ramp metering rates by metering strategy.
  4. Table 3-4. Strategies supporting real-time traffic management.
  5. Table 3-5. Data supporting offline traffic planning and administration.
  6. Table 3-6. Collision avoidance strategies and preventable crash types that are supported by vehicle-mounted sensors.
  7. Table 3-7. Automotive radar requirements for distance warning systems.

CHAPTER 4. IN-ROADWAY SENSOR DESIGN

  1. Table 4-1. Minimum green interval.
  2. Table 4-2. Inductive-loop detector location and timing parameters.
  3. Table 4-3. Dilemma zone boundaries.
  4. Table 4-4. Wide inductive-loop detector dimensions.
  5. Table 4-5. Loop lengths for long-loop-occupancy detection.
  6. Table 4-6. Stopping and clearance distances for intersection width of 48 feet.
  7. Table 4-7. Stopping and clearance distances for intersection width of 15 meters.
  8. Table 4-8. Stopping and clearance distances for intersection width of 76 feet.
  9. Table 4-9. Stopping and clearance distances for intersection width of 23 meters.
  10. Table 4-10. Inductive-loop detector placement in extension or extended call systems used to ameliorate effects of dilemma zones.
  11. Table 4-11. Inductive-loop detector placement in multiple-point detection systems used to ameliorate effects of dilemma zones.

TABLES IN VOLUME II

CHAPTER 5. SENSOR-INSTALLATION TECHNIQUES

CHAPTER 6. SENSOR MAINTENANCE

APPENDIX A. INDUCTIVE-LOOP SYSTEM EQUIVALENT CIRCUIT MODEL

APPENDIX B. CURRENT SHEET FORMULA FOR CALCULATION OF LOOP INDUCTANCE

APPENDIX C. LOOP INDUCTANCE AND QUALITY FACTOR TABLES

APPENDIX D. ELECTRICAL CHARACTERISTICS OF WIRE AND CABLE

APPENDIX E. VEHICLE DETECTION SENSITIVITY FORMULAS FOR RECTANGULAR LOOPS

APPENDIX J. NEMA DETECTOR STANDARDS EXCERPTS

APPENDIX K. CALTRANS TRANSPORTATION ELECTRICAL EQUIPMENT SPECIFICATIONS (TEES) FOR ELECTRONICS UNITS AND MAGNETIC DETECTORS

APPENDIX M. EXTENT AND CAUSES OF INDUCTIVE LOOP FAILURES

APPENDIX N. GROUNDING (DESIGN GUIDELINES)

APPENDIX O. GROUNDING (MAINTENANCE GUIDELINES)

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