Weigh-In-Motion (WIM) Data Collection & Reporting Office of Highway Policy Information 2012 Highway Information Seminar - Session: 6B Thursday, October 25, :00 am – 9:30 am By: David L. Jones Sr.,Transportation Specialist
Provide Background and Update Describe Truck Weight Program State Reporting Requirements (TMG) Update WIM System Deployment & Sensor Technology Identify Data Collection Issues TWS Status & National Loading Trends Open Discussions dialogue OBJECTIVE
1831Thaddeus Fairbanks 1918BPRs First Road Test 1934 Hayden-Cartwright Act 1939 Type A Loadometer 181 Years of Vehicle Weighing
1942Strain Gage Load Cell 1950O.K. Norman 181 Years of Vehicle Weighing
1985Traffic Monitoring Guide 1955AASHO Road Test Approved 1971TWS Manual 181 Years of Vehicle Weighing 2012Traffic Monitoring Guide Update
Ensure Quality Input Data Provide Latest Procedural and Program Guidelines Transferable Techniques and Procedures ITS Data Bike and Pedestrian TMG Update Project Goals
Chapter 1 – Traffic Monitoring Theory, Technology, and Concepts Chapter 2 – Traffic Monitoring Program – Business Planning and Design Chapter 3 – Traffic Monitoring Methodologies Chapter 4 – Traffic Monitoring for Non- Motorized Traffic Table Of Contents
Chapter 5 – Transportation Management and Operations Chapter 6 – HPMS Requirements for Traffic Data Chapter 7 – Traffic Monitoring Data Formats Appendices: Table Of Contents
Speed Non-motorized data Data Formats Reporting Requirements Expanded Examples, Appendixes and References What’s New
Updated ~2+ days NHI TMG Training Course Public Website: Other Associated Work Project Information // Project Schedule // Panel Members // Panel // Public Review and Comment
Weigh-In-Motion? Process of Measuring Dynamic Tire Forces Using in Pavement Sensors To Estimate a Static Vehicle Weight
Why Weigh?
Pavement Design / Maintenance
Bridge Design / Loading
Pavement Design / Maintenance Bridge Design / Loading
Pavement Design / Maintenance Bridge Design / Loading Enforcement
Pavement Design / Maintenance Bridge Design / Loading Enforcement Research
Pavement Design / Maintenance Bridge Design / Loading Enforcement Research Freight Movement
Why Weigh in Motion? Traffic Stream Use of the Highway System
Truck Weight Program Components Users Needs –End in Mind –2002 Pavement Design Guide Resources –Federal-aid and construction funds Locations –Available funds Truck Weight Groups –Criteria for groups
A.Define truck weight roadway groups Maximum Weight in a Given Weight Group (x 1,000 lbs) Fraction of Axles in Each Weight Group Heavily Loaded Moderately Loaded Lightly Loaded Tandem Axle Load Distributions
A.Define truck weight roadway groups RuralUrban Interstate and arterial major through-truck routes Interstate and arterial major truck routes Other roads (e.g., regional agricultural roads) with little through traffic Interstate and other freeways serving primarily local truck traffic Special cases (e.g., recreational, ports)
A.Define truck weight roadway groups B.6 sites / group RuralUrban Interstate and arterial major through-truck routes Interstate and arterial major truck routes Other roads (e.g., regional agricultural roads) with little through traffic Interstate and other freeways serving primarily local truck traffic Special cases (e.g., recreational, ports)
A.Define truck weight roadway groups B.6 sites / group C.One continuous WIM within group Capture day-of-week and seasonal changes within each group
A.Define truck weight roadway groups B.6 sites / group C.One continuous WIM within group Capture day-of-week and seasonal changes within each group D. Calibrate, Calibrate, Calibrate
Criteria for Groups Can be easily applied in any state Logical means for disguising between heavy and light loaded roadways
WIM Sensor Technology Bending Plates” – Strain gauge/load cells Load Cell” – Hydraulic load cells Piezo” -electric cables/film/quartz Capacitance” mats/pads/strips Bridge” Strain gauges on bridge beams
Minimum quarterly WIM submittal truck weight data from permanent weight-in-motion (WIM) sites within 26 days after the close of the quarter. ***Monthly WIM Submittal is Encouraged*** Reporting Requirements
Truck Weight Study Status
TMAS Products System wide Vehicle weight by vehicle class Axle Load Distribution Equivalent Single Axle Load (ESAL) Day-of-Week and Seasonal Patterns
W-Tables (TWS) W1-Weigh Station Characteristics W2-Comparison of Weighted vs. Counted W3-Average Empty, Loaded, and Cargo Weights W4-Equivalency Factors W5-Gross Vehicle Weights W6-Overweight Vehicle Report W7-Distribution of Overweight Vehicles VTRIS Reports:
Rural Interstate Travel by Vehicle Type 1Equivalent axle loads provide a means of measuring vehicle wear on pavements by relating them to an80 kilonewton (18,000 pound) single axle load. 2 All 2-axle, 4-tire trucks. Includes pickup trucks, panel trucks, vans and other vehicles (such as campers,motor homes, etc.) 3 All vehicles on a single frame have either 2 axles and 6 tires or 3 or more axles (including camping andrecreational vehicles and motor homes.) Average Daily TrafficEquivalent Single Axle Loads Percent Automobiles, Buses and Light Trucks Heavy Single Unit Trucks All Combination Trucks Distribution of Average Daily Traffic Volumes and Equivalent Axle Loads on the Rural Interstate System as a Percent of Total
Urban Interstate Travel by Vehicle Type 1Equivalent axle loads provide a means of measuring vehicle wear on pavements by relating them to an80 kilonewton (18,000 pound) single axle load. 2 All 2-axle, 4-tire trucks. Includes pickup trucks, panel trucks, vans and other vehicles (such as campers,motor homes, etc.) 3 All vehicles on a single frame have either 2 axles and 6 tires or 3 or more axles (including camping andrecreational vehicles and motor homes.) Average Daily TrafficEquivalent Single Axle Loads Percent Automobiles, Buses and Light Trucks Heavy Single Unit Trucks 3- & 4-Axle Combination Trucks Distribution of Average Daily Traffic Volumes and Equivalent Axle Loads on the Rural Interstate System as a Percent of Total
Greater than 10M tons per year 5 to 10 M tons per year Less than 5 M tons per year
Monthly Average GVW Variations
Hourly Average GVW Variations
Data Quality Act Data Quality Quality Assurance Statement The Federal Highway Administration 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. Requests for Correction On October 1, 2002, the Department of Transportation (DOT) issued agency guidelines to ensure the quality of disseminated information. If you are affected by information that the Department has disseminated on or after October 1, 2002 (i.e., if you are harmed because the information does not meet the standards of the guidelines or a correction of the information would benefit you), you may request that the Department correct that information. We regard information originally disseminated before October 1, 2002, as being subject to this correction process only if it remains readily available to the public (e.g., it is posted on a DOT website) and it continues to play a significant, active role in Department programs or in private sector decisions. Information on how to submit a request can be found at
Data Quality Elements Data collection Data Processing Process improvement Implementation plan Data quality program.
FUTURE WIM’s Future Role
National estimates of heavy vehicle highway travel on a monthly basis National estimates of axle loadings and highway ton-miles of freight moved each month, and Highway specific estimates of truck volumes and loadings Travel Monitoring Analysis System
46 Traffic Volume Trends GIS Freight Management Safety “THE EASY BUTTON” Travel Monitoring Analysis System
Session 6B Summary Truck Weight User Needs? Truck Weight Program Components? Submittal Requirements? Data Quality? Truck Weight Data Reports?
Questions What questions do you still have about the Traffic Monitoring Program? Expectations met?
THANK YOU ! David L. Jones Sr.