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Slide 1

Traffic Monitoring Guide - Training Mini-Course

Powerpoint presentation (154 KB)

Slide 2

Instructors

• Jeff Patten
  • Phone (202) 366-5052
  • Email jeff.patten@fhwa.dot.gov
• Harshad Desai
  • Phone (202) 366-5047
  • Email harshad.desai@fhwa.dot.gov
• David Jones
  • Phone (202) 366-5051
  • Email david.jone@fhwa.dot.gov

Slide 3

Course Objectives

• Define the structure of a traffic monitoring program
• Describe the purpose and appropriate use of the TMG procedures
• Use the procedures for obtaining data for Federal and State programs
• Identify issues impacting data quality

Slide 4

Agenda

• 8:00 Introduction
• 8:45 Volume
• 9:30 Break
• 9:45 Classification
• 10:15 Weight
• 10:45 Summary
• 11:00 Adjourn

Slide 5

Define the Structure

• Main Components
  • Continuous counts
  • Short term counts
  • Special need counts
• Design 4 C's
  • Comprehensive
  • Cooperation
  • Coordination
  • Consistent

Slide 6

Traffic Data Types

• WIM
  • 31 — Weight data provides damage factors used for pavement design.
• CLASSIFICATION
  • 2299 — 48 Hr Volumes and Classification (Short term counts Monitoring Sites)
    
    
  • 245 — (Continous counts Monitoring Sites)
    1. Axle & seasonal correction factors
    2. K, D, & T factors
• COUNTS
  • 5051 — 48 Hr Volumes (Short term counts Monitoring Sites)
  • 50 (Continous counts Monitoring Sites)
    1. Seasonal correction factors
    2. K amp; D factors

Slide 7

Describe the Purpose and Appropriate Use of the TMG Procedures

• Starting point
• One size doesn't fit all
• Improve
• Advance
• Insure

Slide 8

Use the procedures for obtaining data for

• Federal Programs
  • HPMS
  • TVT
  • LTPP & Truck and Weight Studies
• State Programs
  • Planning
  • Design
  • Safety
• Other data users

Slide 9

Identify issues impacting data quality

• Quality Control "collection"
• Quality Assurance "processing"
• Action Plan

Slide 10

Guidance Repair

• Data Elements
  • Traffic Management System Regulation
  • State Procedures
    • HPMS Field Manual
    • Traffic Monitoring Guide
    • AASHTO Guidelines for Traffic Data
    • ASTM Standards

Slide 11

Traffic Monitoring System Regulation (TMS)

• A traffic monitoring system means a systematic process for the collection, analysis, summary, and retention of highway and transit related person and vehicular traffic data.
  
  
• 23 CFR Part 500 B
  http://www.fhwa.dot.gov/legsregs/directives/fapg/cfr050b.htm
  
  
• Operational October 1, 1997
  
  
• No Sanctions

Slide 12

TMS to be used when data:

• are supplied to the U.S. DOT
• are used in support of studies or systems which are the responsibility of the U.S. DOT
• collection is supported by programs of the U.S. DOT
• are used in the apportionment or allocation of Federal funds by the U.S. DOT
• are used in the design or construction of an FHWA funded project; or
• are required as part of a federally mandated program of the U.S. DOT.

Slide 13

TMS Extent of Application

• All public roads except
  • Rural local
  • Urban local
  • Rural minor collector or
  • those that are federally owned
• State's TMS applies to all data used for the enumerated purposes regardless of source, including:
  • local governments and
  • All other public or private entities

Slides 14-15

TMS Components

• Shall meet precisions of HPMS
  
  
• Continuous Counters sufficient to develop DOW, Seasonal, Axle, and Growth factors
  
  
• Short Counts:
  • Adjusted to AADT
  • VC on NHS sufficient to provide (3-yr cycle) on major links:
    • Single Trailer Combo, Multi Trailer Combo, 2A4T,Buses, Total
  
  
  
• Vehicle Occupancy for Auto, Light Trk, Bus
  
  
• Field Ops
  • Equipment Testing process and frequency
  • Document number, duration, cycle, temporal and spatial distribution
  
  
  
• Retention of original data
  
  
• Factoring Procedures
  
  
• Use of month, DOW, Axle, Growth with factors reviewed annually and updated every 3 yrs
  
  
• Process used to produce AADT will be documented
  
  

Slides 16 and 17

HPMS Field Manual

Appendix F - Traffic Monitoring —Procedures for HPMS

• HPMS samples on 3 year cycle
• All roads, not just state owned
• Traffic counts on all roads on 6 year cycle — volume groups
• 48 hour monitoring
  See http://www.fhwa.dot.gov/ohim/hpmsmanl/hpms.htm
• Continuous
  • At least one ATR on each PAS/NHS
  • At least 2 full days for each day of week for each month
• Short Term
  • Random scheduled geographically and temporally
  • Use axle correction factors
  • Machine error factors not allowed

Slide 18

2001 Traffic Monitoring Guide

• Support HPMS
• Improve quality of truck information
• Describe "good practice"
• Provide flexibility

Slide 19

Data Collection Framework

• All program elements (volume, class, and weight) require
  • Continous traffic counts (CTR, ATR, PTR....)
  • Short term counts
  • Special counts

2001 Traffic Monitoring Guide

Slide 20

Slides 21-23

• Traffic Monitoring Program Elements
  • Traffic Volume
  • Vehicle Classification
  • Truck Weight
• Initial Classification Goal:
  • 25 — 30% of all counts [volume+class] be classification counts
  • At least one classification count per "road"
  • Supports a factoring approach that accounts for truck variability, not just volume variability
  • Length Classification
• Each "road" should have accurate reliable truck weight information
  • Gross vehicle weights
  • Axle weight distributions
  • Load Spectra
  • Truck volumes
• Truck Groups

Slide 24

2001 Traffic Monitoring Guide

• Key Points
  • Partnerships with data users
  • Emphasis on truck volumes
  • Factor truck counts
  • Use other data sources
  • Truck data — New Pavement Design Guide

Slide 25

AASHTO Guidelines — 1992

• Major objectives and principles
  • Improve the quality of State and national traffic data
  • Move toward standardization of traffic data procedures
  • The concept of truth-in-data

Slide 26

AASHTO Recommendations

• Data collection needs
• Field equipment
• Data editing
• Summarizing data
• Retaining data
• Quality control
• Data definitions

Slide 27

Revise AASHTO Guidelines

• Published in 1992
• New technologies
• New methods
• NCHRP Project 7-16
  • States involved Minnesota, Ohio, California, Idaho, Florida, Pennsylvania
  • Starting Date: March 2005
  • Duration: Two years

Slide 28

ASTM Standards

• E 1318 WIM Equipment
  • Specifications
  • Testing
  • Calibration
• E 1442 Traffic Monitoring
• E 1572 Classifying Vehicles

Slide 29

Data Quality Act

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.

Data Quality

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

Slide 30

FHWA Traffic Data Needs

• HPMS
  • Federal aid fund apportionments
  • Conditions and Performance Report
  • Highway Statistics
• Traffic Volume Trends (TVT)
• Vehicle Classification (HVTIS)
• Truck Weight Study (TWS)
• Safety Statistics

Slide 31

Data Elements

• AADT
• K-factors
• D-factors
• % Trucks
• Average
• Peak
• Load Factors