Post on 16-Dec-2015
Weigh-In-Motion (WIM) Data Collection & Reporting
Office of Highway Policy Information2012 Highway Information Seminar - Session: 6BThursday, October 25, 2012 8:00 am – 9:30 amBy: 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
• 1831 Thaddeus Fairbanks• 1918 BPRs First Road Test• 1934 Hayden-Cartwright Act• 1939 Type A
Loadometer
181 Years of Vehicle Weighing
• 1942 Strain Gage Load Cell
• 1950 O.K. Norman
181 Years of Vehicle Weighing
• 1985 Traffic Monitoring Guide
• 1955 AASHO Road Test Approved• 1971 TWS Manual
181 Years of Vehicle Weighing
• 2012 Traffic 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: http://fhwatmgupdate.camsys.com/
Other Associated Work
Project Information // Project Schedule // Panel Members // Panel // Public Review and Comment
Weigh-In-Motion?
Process of Measuring Dynamic Tire ForcesUsing in Pavement Sensors
To Estimate a Static Vehicle Weight
Why Weigh?
• Pavement Design / Maintenance
• 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)
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50
Fra
cti
on
of
Ax
les
in
Eac
h W
eig
ht
Gro
up
Heavily Loaded
Moderately Loaded
Lightly Loaded
Tandem Axle Load Distributions
A. Define truck weight roadway groupsRural Urban
Interstate and arterial major through-truck routes
Interstate and arterial major through-truck routes
Interstate and arterial major truck routes Interstate and arterial major truck routes
Other roads (e.g., regional agricultural roads) with little through traffic
Other roads (e.g., regional agricultural roads) with little through traffic
Interstate and other freeways serving primarily local truck 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 / groupRural Urban
Interstate and arterial major through-truck routes
Interstate and arterial major through-truck routes
Interstate and arterial major truck routes Interstate and arterial major truck routes
Other roads (e.g., regional agricultural roads) with little through traffic
Other roads (e.g., regional agricultural roads) with little through traffic
Interstate and other freeways serving primarily local truck 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 cellsLoad Cell” – Hydraulic load cellsPiezo” -electric cables/film/quartzCapacitance” mats/pads/stripsBridge” 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
TMASProducts• 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 VehiclesVTRIS Reports:
https://fhwaapps.fhwa.dot.gov/vtris-wp/
COMPARISON OF GROWTH IN VOLUME AND LOADINGS ON THE RURAL INTERSTATE SYSTEM
1970 72 74 76 78 80 82 84 86 88 90 92 94 96 98 00 02 04 06 080
100
200
300
400
500
600
700
RURAL AVERAGEDAILY LOAD
RURAL AVERAGEDAILY TRAFFIC
YEARSource: Truck Weight Study
Rural Interstate Travel by Vehicle Type
1 Equivalent axle loads provide a means of measuring vehicle wear on pavements by relating them to an 80 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 and recreational vehicles and motor homes.)
80
246
16
92
Average Daily Traffic Equivalent Single Axle Loads0
20
40
60
80
100
Per
cent
Automobiles, Buses and Light Trucks
Heavy Single Unit Trucks
All Combination Trucks
Distribution of Average Daily Traffic Volumes and EquivalentAxle Loads on the Rural Interstate System as a Percent of Total
Urban Interstate Travel by Vehicle Type
1 Equivalent axle loads provide a means of measuring vehicle wear on pavements by relating them to an 80 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 and recreational vehicles and motor homes.)
89
44
14
7
82
Average Daily Traffic Equivalent Single Axle Loads0
20
40
60
80
100
Per
cent
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
Source: VTRIS Truck Weight Study
Distribution of Vehicle Travel by Laneby Vehicle Type
57.1
42.9
21.3
78.7
11.3
88.7
Lane 2 Lane 10
10
20
30
40
50
60
70
80
90
100
Per
cen
t
Greater than 10M tons per year5 to 10 M tons per yearLess than 5 M tons per year
0
20,000
40,000
60,000
80,000
100,000
120,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Av
era
ge
Da
iy G
VW
Month
Statewide Average Gross Vehicle Weight (GVW)by Functional Classification
Single_Unit
Single_TT
Multi_TT
Monthly Average GVW Variations
State of Maryland South Bound I83 June 25 2004
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour of Day
Ave
rag
e G
ross
Veh
icle
Wei
gh
t(P
ou
nd
s)
Average GVW Class 9 Truck
Hourly Average GVW Variations
Data Quality ActData 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 http://dms.dot.gov/dataquality.cfm
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 TrendsGISFreight ManagementSafety
“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.djones@dot.gov