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The National Traffic Data Acquisition Conference was attended by representatives from all 50 states and many foreign countries. Presentations and demonstrations indicated that the collection of traffic data will be an area of increasing importance due to recent and pending Federal Legislation. The papers contained within this publication are a compilation of those presented at the Conference. Following is a list of those papers. Abstracts are included where available.
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OPENING GENERAL SESSION

Automated Traffic Data Collection and Demonstration Project 76
Perry M. Kent, FHWA, Washington, D.C.

Long Term Pavement Performance Continuation of SHRP-LTPP at FHWA
Paul Teng, FHWA-LTPP Division, Washington, D.C.

FHWA Perspectives on the Need for Improvement in Traffic Data Acquisition
E. Dean Carlson, FHWA, Washington, D.C.

An Individual Perspective on the ASTM and AASHTO Traffic Initiatives
David P. Albright, Strategic Alliance for Transportation Research, Albuquerque, NM

Interstate 95 Multi-State Traffic Monitoring Evaluation Project
Bruce Littleton, Delaware DOT and Ran Marshall, Pennsylvania DOT

Clean Air Act and Its Implications on Traffic Data Collection
Bob O'Loughlin, FHWA, San Francisco, CA

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PLANNING AND RESEARCH - PART I

Summary of Session
Peggy Eidman, Maryland DOT

Utilization of Weigh In Motion Data for Transportation Planning and Decision Making
Jerry J. Hajek, John R. Billing, and Gerhard Kennepohl, Ontario Ministry of Transportation, Ontario, Canada

Participation in the SHRP and C-SHRP long term pavement performance monitoring programs has led all state and provincial highway agencies in the United States and Canada to install at least one weigh-in-motion (WIM) scale. The WIM scales provide not only the traditional traffic monitoring data, but also a very large amount of detailed data for individual vehicles including length, speed, axle weights and axle spacing. Because the WIM data are often associated only with pavement research, many potential users are not yet aware of (a) the capabilities of WIM technology, (b) the type of data available, and (c) the opportunities to utilize WIM data in their areas of expertise.

This paper briefly describes traffic monitoring data generated by typical WIM installations. A number of practical examples show that WIM data are useful for a wide range of transportation planning and decision-making purposes. The specific application areas discussed include:

• planning and programming of transportation facilities
• pavement design and rehabilitation
• apportionment of pavement damage
• compliance with vehicle weight regulations
• development of geometric design standards
• compliance and regulatory policy development of truck dimensions
• safety analysis
• traffic operation and control
• analysis related to highway bridges

WIM data can be used in all these application areas. Its usefulness cuts right across the organizational structure of any highway agency. Thus, WIM data should be considered corporate data, and should be managed accordingly.

Performance and Application of a Capacitative Strip Tyre Force Sensor
Dr. David J. Cole and D. Cebon, University of Cambridge, Cambridge, U.K.

A capacitative strip Weigh-in-Motion (WIM) sensor is described and the theory of its operation is discussed. A theory is then developed for the design of multiple-sensor WIM systems to minimize the errors caused by the dynamic axle loads of heavy vehicles moving at highway speeds. The theory is verified using measurements from a wheel load measuring mat of total length 38 m. incorporating 96 of the capacitative strip WIM sensors. conclusions are drawn regarding the accuracy of the sensors and the design of multiple-sensor WIM systems.

Development of a New England Vehicle Classification and Truck Weighing Program
Frederick P. Orloski, FHWA, Albany, NY

Identifying and Advancing Long-Range and Short-Range Research Needs
John L. Hamrick, Idaho DOT

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PLANNING AND RESEARCH - PART II

Summary of Session
Jon P. Underwood

Arkansas' Experience Piezo-Electric Cable Weigh In Motion Systems in Asphaltic Concrete Pavements
Thomas F. Black, Arkansas State Highway and Transportation Department

The Feasibility of Multiple-Sensor Weighing for Increased Accuracy of WIM
Dr. Tom Gillespie and Steven M. Karamihas, University of Michigan Transportation Research Institute

Efforts to measure truck axle weights at normal highway speeds by a single scale installed in the road are ineffective because of the dynamic load variations on the axle. The extended measurement distance required to average out load variations is in conflict with the layout of axles on typical trucks. As a consequence, multiple weight sensors are required. The performance of multiple-sensor weigh-in-motion systems are evaluated measuring the load of 95 axles on 21 simulated trucks. A three-sensor system appears capable of measuring loads on axles with leaf-spring and some air-spring suspensions to an accuracy of 5% to 8% on most roads. Measurement of axles with poorly damped wheel-hop resonance modes is much less accurate, with errors on the order of 15%.

Video Imaging for Vehicle Classification
Randy Ronning, California DOT

Advances in Fiber Optic Weigh In Motion Technology at the Oak Ridge National Laboratory
Jeff D. Muhs, Oak Ridge National Laboratory, Oak Ridge, TN

Experimental results on a portable, low-speed fiber optic weigh-in-motion system are described which demonstrate the applicability of fiber optic-based sensors in transportation, defense, and law enforcement applications where accurate weight determination of moving vehicles is necessary. Details are given on the systems' measurement approach, specifications, and limitations. In the paper a discussion of the sources of error associated with low-speed weigh-in-motion systems and methods of minimizing these errors for practical deployment are given along with a discussion of the characteristics of silicone rubber optical fiber.

A Description of the California Highway Performance Monitoring System (HPMS) Program
Paul Teeter, California DOT

INTELLIGENT VEHICLE/HIGHWAY SYSTEMS (IVHS) AND COMMERCIAL VEHICLE (CVO) TECHNOLOGIES

Development of An Expert System for Traffic Analysis
Gregory Fulton, Colorado Department of Highways; George Hovey and Dr. Henry Horsey, Ballofet and Associates, Denver, CO

The Advantage I-75 Program
James W. Schmidt, JHK & Associates

Automatic Vehicle Identification and Toll Collection
Dr. Claude Maeder, ECM, France

Meteor Burst Communication Project
Charles Cerocke, Nevada DOT

SHRP-FHWA LONG TERM PAVEMENT PERFORMANCE (LTPP) PROGRAM

Synthesis of FHWA-LTPP Traffic Data Collection
Michael M. Marti and Guy W. Kohlnhofer, Braun Intertec, Minnesota

Regional Conference - Traffic Data Collection, North Central Region
Michael Marti, Braun Intertec, Minnesota

Summary Report, SHRP Traffic Data Collection Status in the Southern Region
Mark Gardner, Brent Rauhut Engineering, Austin, TX

Summary of Questionnaire Responses from State/Provincial Agencies Within the North Atlantic Region
Randy Plett, Pavement Management Systems, New York

LTPP Western Region Coordination Office SHRP/FHWA-LTPP Program
Earl Laird, Nichols Consulting Engineers, Reno, Nevada

Future Traffic Activities in Support of SHRP/FHWA-LTPP
H. K. (Kris) Gupta, FHWA-LTPP Division, Washington, D.C.

VEHICLE WEIGHT ENFORCEMENT

Port of Entry Operations
Dave Nakao, California DOT and Sgt. Ray Wineingar, California Highway Patrol

Mainline Screening for Enforcement
Milan Krukar and Ken Evert, Oregon DOT

Currently, truck weight, permit, and registration verification procedures at weigh stations and ports-of-entry are labor intensive and time consuming. This will become an even greater problem in the future, given the rate of increase in infrastructure demand (i.e., greater number of commercial vehicles) and the limitations being imposed on state budgets. At the same time, the trucking industry is demanding the use of technology to prevent delays and stoppages at truck inspection facilities. This demand is somewhat justified in that only a small percentage of vehicles are in fact in violation of weights, dimensions, or credential regulations.

The State of Oregon has been screening heavy vehicles since 1984 on entrance ramps at several port-of-entry (POE) using weigh-in-motion (WIM), automatic vehicle identification (AVI), and signal lights to direct vehicles. These on-ramp screening systems have been a success, but there are still problems with queuing during peak periods and distraction with signal lights. In order to maximize efficiency, it is desirable to screen vehicles on the mainline at highway speeds. This would avoid congestion and other safety problems by decreasing the volume passing over the static scales through the port/weigh station and provide the least possible delay to the trucking industry.

This paper discusses the principles of mainline screening and describes the State of Oregon's past, present, and future mainline screening projects.

California's Experience with WIM at Enforcement Scales
Dave Nakao and Ting Co, California DOT

The FHWA and State Weight Enforcement Program
Tom Klimek, FHWA, Washington, D.C.

DATA COLLECTION, PROCESSING AND ANALYSIS

Summary of Workshop on Data Collection, Processing and Analysis
Perry M. Kent, FHWA, Washington, D.C.

Travel Data Collection for Air Quality Planning and Congestion Management
Charles R. Goodman, FHWA, Washington, D.C.

Accuracy of Traffic Monitoring Equipment Project
R. Scott Knight, Georgia DOT

An Update on FHWA's Traffic Monitoring Guide Software
Ralph Gillmann, FHWA, Washington, D.C.

IMPLEMENTATION OF THE HELP PROJECT

Summary of Session
Milan Krukar, Oregon DOT

Technical Problems Related to Data Processing
Rich Quinley and Koney Archuleta, California DOT

Technical Problems Related to Equipment Installation
Edward K. Green and Joe Waicekauskas, Arizona DOT

Advanced Transportation Controller
Terry Quinlan, California DOT

DESIGN AND MAINTENANCE PROGRAM

Summary of Session
Craig Copelan, California DOT

Weigh In Motion Data Used in Pavement Design
Herbert F. Southgate, Kentucky Transportation Center, Lexington, KY

Vehicle Detector Study
Jeff McRae, California DOT

Collection of Traffic Data from 170 Signal Controller
Rick Wells and Bob Triplett, California DOT

The Monitoring of Structures to Determine the Effects of Truck Traffic
Harold Bosch, FHWA, Washington, D.C.

Bridge engineers must make many assumptions regarding a structure's loading conditions and response behavior. In recent years, automated instrumentation systems have been used to acquire detailed information on truck characteristics and bridge response at more than 80 sites. This data has been and is being used to improve our understanding of the effects of truck traffic on structures. Some applications will be discussed in what follows.

Installation of Piezo-Electric Axle Sensors
Nick Jones and Steve Malkson, California DOT

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CLOSING GENERAL SESSION

A Concept of IVHS in Commercial Vehicle Operation: The HELP/Crescent Program
Dr. C. Michael Walton, Center for Transportation Research

The HELP Program and Crescent Demonstration Project is a bi-national multi-jurisdictional cooperative research and demonstration project involving the public and private sectors in an application of advancing technologies in the creation of an integrated heavy vehicle management system with applications to both highway and vehicle systems. This initiative is a leading example of the Intelligent Vehicle Highway Systems (IVHS) in commercial vehicle operations (CVO).

The selected technologies are being integrated into a heavy vehicle management system. These technologies include: (1) automatic vehicle identification (AVI), (2) weigh-in-motion (WIM), (3) automatic vehicle classification (AVC), (4) data communication networks and systems integration. The program, initiated approximately eight years ago, consists of three phases which include assessing the feasibility of the concept, technical studies involving laboratory and field tests, and lastly, the demonstration phase. Perhaps the most significant activity of this project centers on the subject of institutional arrangements associated with the integration of emerging technologies with current operational policies and practices, within both government and industry sectors.

The demonstration element of the program, referred to as the Crescent Demonstration Project, began in 1991 and involves six U.S. states and one Canadian province. The project will be phased into a full scale operation over the next three years. It is estimated that the cost of this program to date is approximately $20 million shared by both industry and government in testing this landmark program. This paper provides an overview of the program and the components of the implementation plan.

Conference Summation
Perry M. Kent, FHWA, Washington, D.C.

Appendix 1: List of Registered Participants
Appendix 2: The Emphasis on Automated Traffic Data Collection Technology for the Future, Clyde E. Lee, The University of Texas at Austin

key words: automatic vehicle classification, automatic vehicle identification, traffic counting equipment, traffic data collection, Weigh-In-Motion

This document is available to the public through NTIS, Springfield, VA 22161.

Last Modified: November 2007

Maintained by: traffic@nmsu.edu

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