{"response":{"docs":[{"id":"dlg_ggpd_y-ga-bt700-pp4-bs1-bt7-b2013-belec-p-btext","title":"2013 Georgia Traffic Monitoring Program [Dec. 2013]","collection_id":"dlg_ggpd","collection_title":"Georgia Government Publications","dcterms_contributor":["Georgia. Department of Transportation. Division of Permits and Operations. Office of Transportation Data"],"dcterms_spatial":["United States, Georgia, 32.75042, -83.50018"],"dcterms_creator":["Georgia. Department of Transportation. Division of Permits and Operations. Office of Transportation Data"],"dc_date":["2013-12"],"dcterms_description":["Began in 2012?","Description based on: 2012 ; title from PDF title page (Georgia Government Publications database, viewed June 13, 2017).","Latest issue consulted: 2013 (Georgia Government Publications database, viewed June 13, 2017)."],"dc_format":["application/pdf"],"dcterms_identifier":null,"dcterms_language":["eng"],"dcterms_publisher":["Atlanta, Ga. : Georgia. Department of Transportation. Division of Permits and Operations. Office of Transportation Data"],"dc_relation":null,"dc_right":["http://rightsstatements.org/vocab/InC/1.0/"],"dcterms_is_part_of":null,"dcterms_subject":["Georgia"],"dcterms_title":["2013 Georgia Traffic Monitoring Program [Dec. 2013]"],"dcterms_type":["Text"],"dcterms_provenance":["University of Georgia. Map and Government Information Library"],"edm_is_shown_by":["https://dlg.galileo.usg.edu/do:dlg_ggpd_y-ga-bt700-pp4-bs1-bt7-b2013-belec-p-btext"],"edm_is_shown_at":["https://dlg.galileo.usg.edu/id:dlg_ggpd_y-ga-bt700-pp4-bs1-bt7-b2013-belec-p-btext"],"dcterms_temporal":null,"dcterms_rights_holder":null,"dcterms_bibliographic_citation":null,"dlg_local_right":null,"dcterms_medium":["publications (documents)"],"dcterms_extent":null,"dlg_subject_personal":null,"iiif_manifest_url_ss":null,"dcterms_subject_fast":null,"fulltext":"Traffic Monitoring Program 2013 \n \nThis document is an overview of Georgia's extensive, quality driven traffic monitoring program including continuous monitoring, short-term monitoring, weigh-inmotion, and other sources of traffic data. Quality control and assurance will be outlined for both the weekly and annual data processes. \nOffice of Transportation Data \nFacilitator: Jane Smith, State Transportation Data Administrator \nPrepared By: Kiisa Wiegand, Business Analyst \nOriginal Draft Date: 4/5/2012 Date of Last Revision: 12/15/2013 \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTABLE OF CONTENTS \nI. PURPOSE......................................................................................................................... 2 \nII. BACKGROUND ................................................................................................................ 2 \nIII. TRAFFIC DATA COLLECTION PROGRAM OVERVIEW................................................. 3 \nIV. TRAFFIC DATA COLLECTION ........................................................................................ 4 \nContinuous Counts ......................................................................................................... 4 Portable Traffic Monitoring System (PTMS) .................................................................. 4 Short-Term Counts.......................................................................................................... 4 Portable and Continuous Weigh-In-Motion (WIM)......................................................... 4 Special Requests............................................................................................................. 4 ITS and Data Sharing ...................................................................................................... 4 Research .......................................................................................................................... 5 \nV. CONTINUOUS MONITORING PROGRAM ....................................................................... 6 \nSelection Criteria for Installation of a New ATR Site .................................................... 8 \nVI. SHORT-TERM MONITORING PROGRAM ....................................................................... 9 \nNumber of Counts, Period of Monitoring, and the Cycle of Monitoring ...................... 9 Spatial and Temporal Distribution of Traffic Counts ...................................................10 \nVII. WEIGH-IN-MOTION PROGRAM .....................................................................................11 \nVIII. QUALITY CONTROL AND ASSURANCE .......................................................................12 \nIX. WEEKLY DATA PROCESSING ......................................................................................13 \nWeekly Data Processing for Continuous Monitoring Sites .........................................13 Weekly Data Processing for Short-Term Monitoring Sites..........................................15 \nX. ANNUAL DATA PROCESSING.......................................................................................18 \nManagement of Traffic Count Segments ......................................................................19 Calculation of Traffic on High Volume Roads (Step Down Method) ...........................20 Traffic Count Collection and Estimation on Local Roads ...........................................22 Traffic Adjustment Factors ............................................................................................23 \nXI. OTHER CONSIDERATIONS............................................................................................26 \nREFERENCES .........................................................................................................................27 \nAppendix A: FHWA 13-Bin Vehicle Classification Scheme..................................................28 \nAppendix B: 2011 to 2013 Portable Traffic Collections ........................................................29 \nAppendix C: Permanent Weigh-In-Motion Sites ...................................................................31 \nAppendix D: Portable Weigh-In-Motion Sites........................................................................32 \nAppendix E: Georgia Counties and FIPS Identification Numbers .......................................34 \nAppendix F: Traffic Calculations ...........................................................................................35 \n \n2013 Traffic Monitoring Program \n \n1 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nI. PURPOSE \nFederal Regulations 23 CFR 500.202 states, \"Traffic monitoring system means a systematic process for the collection, analysis, summary, and retention of highway and transit related person and vehicular traffic data.\" Federal Regulations 23 CFR 500.203 mandates, \"Each state shall develop, establish, and implement, on a continuing basis, a TMS to be used for obtaining highway traffic data...\" This document is intended to record the current procedures and practices of the Georgia Department of Transportation's traffic monitoring system. \nThis document provides a comprehensive analysis that fulfills the Federal regulation stated above. The study of traffic data procedures and monitoring is an extensive and very detailed subject with numerous publications and publicly available documentation. The focus of this document will be constrained to specifics on the Office of Transportation Data's management of the traffic data collection program, as currently performed, including collecting traffic data; quality control and assurance; weekly and annual data processing; and other considerations. \n \nII. BACKGROUND \nThe Federal Highway Administration (FHWA) requires every state to submit an annual Highway Performance Monitoring System (HPMS) report containing traffic count data, physical characteristics and other pertinent road data. This submittal is used in legislation, and to determine state funding of highway and road projects. According to the HPMS Field Manual, \"State Maintenance of a comprehensive traffic monitoring data program to provide quality, timely, and complete traffic volume and vehicle classification data is important for meeting HPMS requirements.\" This report serves as a primary component for determining the Federal transportation funding apportionment allocated to states. \nThe data that the Office of Transportation Data (OTD) collects is used for many reasons by internal departments, including the Office of Planning, the Office of Bridge Design and the Office of Materials and Research. Traffic counts are used to determine traffic patterns and flows for modeling purposes. They are also used to alleviate congestion with the construction of new routes or alternate designs. The Office of Bridge Design uses Annual Average Daily Traffic (AADT) data to determine the Bridge Sufficiency Rating. Additionally, the Office of Materials Research uses a combination of truck percentages and AADT data to develop factors that assess the deterioration of pavement. The Traffic Operations Office uses the volume data for safety related purposes (e.g., calculating crash rates and addressing safety issues). \nOTD provides data to a large variety of external customers. Customers of the data include transportation planning professionals, educational institutions, design engineers, contractors, real estate agencies, private companies, and other government agencies. Traffic data is important in determining which routes citizens are using for their daily commutes and leisure travel. During emergency evacuations in inclement weather, critical traffic data is provided to the Georgia Emergency Management Agency and surrounding states. The data is used on both a state and national level by the U.S. Department of Transportation and other customers for planning, modeling, allocation of funding, informational purposes, etc. \n \n2013 Traffic Monitoring Program \n \n2 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nIII. TRAFFIC DATA COLLECTION PROGRAM OVERVIEW \nThe Georgia Department of Transportation's Office of Transportation Data has an extensive, quality driven traffic count program in compliance with all Federal regulations and guidelines. OTD is comprised of two main groups: the Data Administration Group and the Geospatial Transportation Data Group. The Data Administration Group within OTD is responsible for the management of the traffic monitoring program. Traffic count data is collected using continuous counters, portable traffic monitoring system sites, short-term counts, or portable and continuous weigh-in-motion sites. All incoming data is processed with defined and established quality assurance and control measures. \nFHWA requires that all states collect traffic data on the Federal-aid system and provide Vehicle Miles Traveled (VMT) estimates for the local functional classification (FC) systems as directed by Federal regulations. The traffic collection program is designed to provide statistically valid data for the HPMS report which is also required by FHWA on an annual basis. The design of the program closely follows the guidelines of the FHWA's Traffic Monitoring Guide (TMG). The following is a list of the road systems included in the traffic collection program: \n State Routes o Interstates o U.S. Routes \n County Roads  City Streets  Ramps \nGeorgia's State Traffic and Reporting Statistics (STARS) provides AADT counts collected from permanent and portable traffic collection devices throughout the state for every segment of Georgia's Public Road System. The traffic count data is updated on this website annually: http://www.dot.ga.gov/informationcenter/Statistics/stars/Pages/default.aspx. \nGeorgia's Transportation Polling and Analysis System (TPAS) provides traffic data collected 24 hours per day, seven days per week, 365 days per year from permanent traffic collection devices throughout the state for Georgia's Public Road System. Georgia's TPAS is intended for the general public to view current traffic information and historical traffic information dating back to January 1, 2008. The traffic data is updated on this website daily: http://www.dot.ga.gov/informationcenter/statistics/TrafficData/pages/tpas.aspx. \nAlso, Automatic Traffic Recorder (ATR) Traffic Data Reports are published by OTD annually and contain information such as truck percentages by location, vehicle classification by functional classification and hour, and maps for locating ATR sites. The annual reports can be viewed on the following website: http://www.dot.ga.gov/informationcenter/statistics/TrafficData/Pages/atr.aspx. \n \n2013 Traffic Monitoring Program \n \n3 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nIV. TRAFFIC DATA COLLECTION \nThe foundation of the traffic monitoring program is the collection of traffic data. Data can be collected using continuous counters, portable traffic monitoring system sites, short-term counts, or portable and continuous weigh-in-motion sites. Specific sites and types of traffic data collection can be requested by internal GDOT offices only from the Office of Planning. Other potential future sources of traffic data include Intelligent Transportation System (ITS) data and data sharing partnerships. OTD is also participating in a research project with the Georgia Institute of Technology. \nContinuous Counts As of November 2013, OTD has 229 operational, permanent Automatic Traffic Recorder (ATR) sites located on road systems throughout the state. These sites are operational 24 hours per day, seven days per week, 365 days per year excluding any necessary maintenance periods. Permanent sites are polled on a daily basis. Vehicle classification data, traffic volume, and traffic speed is collected. Vehicle classification can also be referred to as classification or class data. \nPortable Traffic Monitoring System (PTMS) The Portable Traffic Monitoring System (PTMS) is a seasonally collected ATR site that does not have either a cellular or a land line connection. A field technician drives to the PTMS site and physically connects a portable traffic loop counter to the site. Traffic data is typically collected for a forty-eight hour period every three months. \nShort-Term Counts Portable collection devices consist of one or more pneumatic tubes stretched across a road and secured on both sides by a field technician. They are connected to a counter on one side of the road and the data is usually collected for a 48-hour period. The devices can be programmed to collect vehicle classification counts as well as volume counts. OTD collects short-term volume counts at approximately 9,000 locations statewide annually. \nPortable and Continuous Weigh-In-Motion (WIM) Portable and permanent Weigh-In-Motion (WIM) sensors and the related data collection equipment are utilized to collect truck weight data statewide. OTD collected data from 34 portable WIM sites located across the state in 2013. Additionally, OTD has 11 permanent WIM sites that collect data 24 hours per day, seven days per week, 365 days per year excluding any necessary maintenance periods. The permanent WIM sites also function as ATRs by providing volume and vehicle classification data. \nSpecial Requests Specifically requested traffic data or special requests are collected at site specific and project specific locations statewide by a traffic data collection consultant through the Office of Planning. Primarily, special requests are requested for project specific studies, which may include short-term vehicle classification, volume counts or turning movements at an intersection. \nITS and Data Sharing The FHWA has encouraged all states to invest in innovative collection practices, such as data sharing or use of Intelligent Transportation System (ITS) data. Through the years, OTD has been actively seeking methods to augment traffic collection through partnerships. From 2006 to the 2012, OTD participated in a series of meetings with Information Technology Outreach Services (ITOS) a part of the University of Georgia's Carl Vincent Institute of Government, and local governments in attempts to collaborate on \n \n2013 Traffic Monitoring Program \n \n4 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nequipment and quality control standards in order to integrate traffic data. Despite quality control and formatting challenges, OTD plans to explore data sharing opportunities more in the future. \nThe ITS or Video Detection System (VDS) data, which is primarily focused on high volume Interstates in metropolitan areas, provides a limited coverage of the traffic monitoring program. In 2011, OTD did a comparison study of ATR data and GDOT's Traffic Management Center's VDS data at several locations around Atlanta and discovered that the AADT volumes varied from 10-50%. It was determined that this was not adequate for AADT and VMT calculations, and reporting purposes. In 2013, a research project compared VDS traffic count data and ATR traffic count data at several Interstate locations resulting in mixed results depending upon the location. OTD is planning to review and use traffic counts on ramps collected by the VDS in 2013. However, defined data quality standards and goals; an examination of the calibration methods; and additional field testing still needs to occur for OTD to widely use the VDS data. \nResearch Many signalized intersections operate under some form of actuated control, in that the intersection approaches have some type of sensor. The most common is an inductive loop which can be configured to provide traffic counts. The Office of Traffic Operations is currently installing traffic signal detectors (inductive loops) in the pavement of various high volume corridors in the Atlanta vicinity. The traffic signal detectors are part of the Regional Traffic Operations Program (RTOP), a multi-jurisdictional, signal timing program with the goal of improving traffic flow and reducing vehicle emissions through improved signal timing. \nIn April 2013, OTD submitted a research needs statement, Integrating Intersection Traffic Signal Data into a Traffic Monitoring Program, to GDOT's Research Advisory Council. A one-year project was approved and is currently being researched by Dr. Angshuman Guin, a professor with the Georgia Institute of Technology. This research project will determine if and how the traffic volume data from the inductive loops can be appropriately utilized in OTD's traffic monitoring program. \n \n2013 Traffic Monitoring Program \n \n5 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nV. CONTINUOUS MONITORING PROGRAM \n \nContinuous monitoring sites or otherwise known as Automatic Traffic Recorder (ATR) sites are installed on all types of roadways (State Routes, County Roads, and City Streets) in both asphalt and concrete. OTD's ATR sites provide volume, speed, and vehicle classification. These sites are continuously operational (24 hours per day, seven days per week, 365 days per year) except during any necessary maintenance periods. The data is stored on site in an ATR Controller Cabinet, prior to being automatically polled every night through the use of land line or cellular modems located at each ATR site. \n \nATR Controller Cabinet \n \nIn Georgia, all ATR sites have equipment configurations that are capable of collecting vehicle classification in addition to volume counts. The ATR sites utilize two Inductive Loop Sensors and one Class II Piezoelectric Sensor embedded in each lane that operates according to the manufacturer's specifications. The system may require one of more of the following items as part of the system: Controller Cabinet, lightning suppressors, pull boxes, conduits, grounding electrodes, poles, concrete aprons, batteries and a solar panel. The piezoelectric sensors, equipment cabinet, inductive loops, cables, leads, and electronic hardware and software are furnished, installed, tested, calibrated and made ready for operation by OTD's contractor. Stringent adherence to calibration and set-up routines for equipment are required to ensure a high level of traffic data accuracy. \n \nATR Installed in Pavement \n \nInductive Loop \n \nPiezoelectric Sensor \n \n2013 Traffic Monitoring Program \n \n6 |Page \n \n Georgia DOT Georgia ATR Site Locations \nATR sites provide valuable data statistics, such as: \n AADT, vehicle classification, and truck percentages \n Daily, monthly, and axle adjustment factors by traffic pattern group \n Design hour factors (peak hour and 30th highest hour) used for the design of highways \n Traffic growth and patterns  Accurate traffic volume data \nused to calculate high volume Interstate and other freeway traffic (Step Down Method) \n2013 Traffic Monitoring Program \n \nOffice of Transportation Data \nAs of November 2013, OTD has 229 operational sites which are managed by the Data Administration Group. This number fluctuates due to road construction and equipment failures. For example, between April 2012 and November 2013, the number of operational ATR sites decreased from 234 to 229. Several of the sites had equipment failures with the piezoelectric loops in the pavement that are scheduled for repair. The other sites are not operational, because there has been road construction in the area which has damaged the sites. Permanent sites are polled on a daily basis by the TPAS software. Incoming data (vehicle classification, volume, and speed) is processed through quality control checks and reviewed by office personnel. Refer to Appendix A: 13-Bin FHWA Vehicle Classification Scheme for detailed illustration on vehicle classification. Atlanta ATR Site Locations \n7 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nSelection Criteria for Installation of a New ATR Site When funding allows for a new ATR site to be installed, a potential new ATR site is chosen based upon defined selection criteria. Then, the Data Administration Group makes a field inspection of any recommended new ATR site to ensure site feasibility and optimal placement for the physical installation of the ATR equipment within the traffic count segment. The Data Administration Group will review the results of the field inspection and approve the installation. The TMG states, \"The main objectives of installing and operating ATRs are to provide highly accurate vehicle classification, track changes in volume over time, determine travel patterns, and create adjustment factors and factor groups.\" \n \nSelection Criteria \n \nField Evaluation \n \nInstallation of a New ATR Site \n \nThe following is a list of the selection criteria that must be considered: \n1. Primary Selection Criteria a. Minimum of five to eight ATR sites per Traffic Factor Group depending upon the traffic patterns and precision desired \n2. Secondary Selection Criteria a. Critical nodes on high volume roads that are used in the Step Down Method b. Replacement of ATR sites that were eliminated due to construction c. Adequate coverage in each of the seven GDOT Districts to ensure geographic differences in travel trends are captured d. Minimum of one operational ATR site per Interstate route e. Minimum of one operational ATR site on other major arterials (e.g., SR-400 and SR-316) f. Area of particular interest to GDOT management for planning purposes or to meet specific Federal requirements (e.g., Mechanistic-Empirical Design Pavement Guide of New and Rehabilitated Pavement Structures) \nIn the last three years due to budget constraints, OTD has only installed one new ATR site located on I-85 in Gwinnett County near Jimmy Carter Boulevard. Seventeen installed ATR sites are inactive due to active construction projects, as of November 2013. OTD is considering installing a new ATR site on SR400 near the new interchange with I-85. The above selection criteria will be used in this decision. \n \n2013 Traffic Monitoring Program \n \n8 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nVI. SHORT-TERM MONITORING PROGRAM \nThe short-term program collects roadway segment-specific traffic count information on a scheduled cycle, collected at each segment for a 48-hour period. The short-term program can also be called the portable collection or the coverage program. The portable collection devices can be configured to collect vehicle classification counts as well as volume counts. OTD collects short-term volume counts at approximately 9,000 locations annually that are distributed statewide. \nPortable collection devices have pneumatic tubes that are stretched across a road and secured on both sides by a field technician. They are connected to a counter on one side of the road where the data is stored. When a vehicle's axle crosses the road tube, the pulse of air that is created is recorded and processed by the traffic counter. Depending upon the type of count needed, one of several different road tube configurations may be set-up in the roadway. \nThere are two different types of portable collection devices used by OTD. In-house staff collects traffic data using the PEEK ADR1000 Portable Traffic Counter/Classifier. The majority of the portable traffic count collection is performed by a contractor that uses the MetroCount 5600 Series Roadside Unit. More information on the two systems can be found at the following websites: http://www.peektraffic.com/products_data.php and http://www.metrocount.com/products/mc5600/. \nNumber of Counts, Period of Monitoring, and the Cycle of Monitoring The Federated Road Enhanced Database (FRED) database houses the Road Characteristics (RC) file, AADT and is used in the development of HPMS. Each road system is defined by a beginning and ending mile point in FRED. The road systems are divided into smaller sections designated with Traffic Count (TC) numbers that have similar traffic volumes. Each TC number has an AADT volume. \nGeorgia has approximately 27,000 TC numbers or segments. It is not possible to collect traffic counts on every road segment in Georgia every year due to practical limitations. Therefore, portable traffic is collected on a defined section of roadway (TC segment) on an annual or cyclical basis which varies with collection intervals ranging from two to four or six years. Traffic counts that are collected on a cyclical basis are adjusted with growth factors in years when they are not counted and marked as Estimated. AADT data is marked as either Estimated or Actual for each collection year for each TC number. \nFederal Regulations 23 CFR 500.204 states, \"Documentation of field operations shall include the number of counts, the period of monitoring, the cycle of monitoring, and the spatial and temporal distribution of count sites.\" The plan for the portable traffic collection program, including the number of counts and the cycle of monitoring, is re-evaluated each year. The period of monitoring is a 48-hour interval with data recorded for every hour of each day; a typical collection time for many state Department of Transportations. The 48-hour data from the portable traffic sites is usually collected Tuesday through Thursday. Refer to Appendix B: 2011 to 2013 Portable Traffic Collections for further details on the number of counts and cycle of monitoring. \n \n2013 Traffic Monitoring Program \n \n9 |Page \n \n Georgia DOT \n \nOffice of Transportation Data \n \nOTD is striving to meet the demands of internal GDOT customers by increasing traffic collection near bridges and, in the future, near railroads. Collecting traffic counts near bridge and railroads will provide valuable information to our internal customers and improves their ability to make informed decisions related to their respective responsibilities. The collected data on these facilities (railroads and bridges) also improves the reliability and timeliness of other federally required reports such as Pontis and the Federal Railroad Administration reports. For reference, Pontis is a software application developed to assist in managing highway bridges and other structures. \nSpatial and Temporal Distribution of Traffic Counts Submitted portable traffic data includes details such as the time, date and location of collection. Garmin Global Positioning System (GPS) units are used during traffic data collection to record the physical location of the collected traffic count. The GPS data is used to create digital maps of the actual collected traffic count sites which are compared to the planned sites and reviewed for quality control. \n \n2013 Traffic Monitoring Program \n \n10 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nVII. WEIGH-IN-MOTION PROGRAM \nEach year, OTD collects Weigh-in Motion (WIM) data at 11 permanent sites and approximately 34 nonpermanent sites located throughout Georgia. Refer to Appendix C: Permanent Weigh-In-Motion Sites and D: Portable Weigh-In-Motion Sites for a complete list of permanent and portable WIM sites, respectively. According to the FHWA guidelines, 10 of these sites should be on Interstate highways. OTD plans to install three more permanent sites. The permanent sites are not polled; data is retrieved at the physical location of the site on a regular basis (approximately once per month). \nThe permanent WIM sites collect vehicle weight, as well as vehicle classification, speed, and volume using a piezo-loop-piezo sensor configuration. The piezo-sensor utilized is a Kistler quartz piezoelectric sensor which provides 95% accuracy when collecting vehicle weight data. Temperature fluctuations do not affect the accuracy of this sensor. \nWeigh-in Motion technology is used to measure vehicle counts, axle and gross weight, vehicle classification, and speed data. WIM data is used for pavement and capacity studies, enforcement and inspection purposes, and for analysis of truck transport practices. The data from these sites are provided to FHWA each year. FHWA runs the data through their software and produces summary W-table reports, which can be viewed at the following website: https://fhwaapps.fhwa.dot.gov/vtris-wp/. \nGDOT has contracted with a consultant to study how to implement the latest Mechanistic-Empirical Pavement Design Guide of New and Rehabilitated Pavement Structures recommendations. The recommendations from this study may call for additional permanent WIM sites; however, funding will need to be identified, because these sites are very expensive to install and maintain. OTD has provided the consultant with collected WIM data and will review the consultant's implementation recommendations when presented. \n \n2013 Traffic Monitoring Program \n \n11 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nVIII. QUALITY CONTROL AND ASSURANCE \nOne of the main goals of the traffic collection program is to provide an accurate portrayal of statewide traffic data and trends. With very few exceptions, OTD's collection program covers the complete State Highway System (about 18,000 miles). Every effort is made to collect the portable traffic data during typical travel conditions (excluding holidays or weekends). A one-time event, such as a county fair, is not an accurate representation of an `average day' and is not a long-term traffic trend. On the other hand, there are conditions which do influence long-term changes in traffic characteristics. The following is a list of some of these conditions: addition of lanes, new intersections/interchanges, new roads, new business or residential developments, changes in the economy, changes in land use, etc. \nQuality assurance refers to efforts made throughout the traffic collection cycle to ensure a high standard of data output. For example, OTD has documented procedures and staff training for the installation and calibration for all types of equipment. Additionally, all equipment installed by a contractor is closely reviewed by the Data Administration Group for adherence to guidelines. OTD employs the following approaches for data quality assurance: \n \nStaff training and use of guidelines Data processing rules and checklists Proven software and data processing methods Tight control on vendors' compliance with guidelines Quality control checks with proven algorithms Stringent adherence to calibration and set-up routines for equipment \n \nAccording to the TMG, \"Each highway agency should have formal, documented rules and procedures for their quality control efforts.\" OTD has established quality control (QC) rules and procedures that evolve in conjunction with new technologies and software enhancements which ensure accurate statewide traffic data. There are many quality control checks preformed on the traffic data by both OTD and the FHWA. For example, each month OTD submits ATR data to the FHWA online through the Travel Monitoring Analysis System (TMAS) which has built-in quality control checks. The Data Administration Group performs quality control reviews on a daily or weekly basis and also conducts a comprehensive review as part of the annual data processing. \n \n2013 Traffic Monitoring Program \n \n12 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nIX. WEEKLY DATA PROCESSING \nThe weekly data processing of incoming ATR data and portable collection data is managed through two different processes mainly within one system (TPAS) which allows office personnel to quickly view the status of incoming data. Any data that does not meet standards of the established quality control rules is either rejected immediately or considered flagged data. The flagged data can be subjected to further review, as deemed necessary. Proven software and data processing methods enable OTD to efficiently process all data with a high level of quality. \nWeekly Data Processing for Continuous Monitoring Sites OTD can immediately identify the current status of every ATR site at a glance, such as: not polling, transfer errors, conversion errors, database errors, broken hardware, successful poll, multi-unit wait, unknown, atypical, and passed or failed QC rules. OTD can re-poll a particular site and also manually upload a data file to the system. Office personnel can view all details pertaining to a site regarding any issue with polling or quality control. A High Level Overview of the ATR QC Process is shown below in Figure 1: \n \nSTART \nIf Yes Then, Poll Again \nInitiate Polling (Autopoll, Manual Poll) \n \n1st Fail to Connect \n \nATR \n \nNo \n \nMaintenance \n \nFailed Queue \nNo \nPolling Successful \n \nAll Detail Goes to Log \n \nAll Detail Goes to Log \nReview \n \nDetailed Log \nAll Detail Goes to Log \n \nRules Thresholds Site Details \nSchedule Lane Relationship Special Event/ Holiday \nResults Log Status of Site Analysis View \nLane Data Classification Data \n \nOverride \nFail \n \nIf No, Day Stored \nas Fail \nYes \n \nPass/Fail QC \n \nTPAS Production \nServer \n \nDay Stored as Pass \n \nIf Yes, Bin File Downloaded \nFigure 1: High Level Overview of ATR QC Process \nThe standard practice is to poll the data from ATR sites each night at 1:00 a.m. However, in inclement weather, OTD can configure the ATR sites to enable Real Time Polling in Emergency Mode which polls data from the ATR sites identified on hurricane evacuation routes every 15 minutes and has priority over the auto-poll. The data is stored in a directory on the TPAS server and is retrieved by the Emergency Operations Center (EOC) for critical planning and use. \nATRs are categorized into groups, such as Interstates or low volume, which apply specific quality control rules. The system also has adjustable thresholds for quality control rules, when applicable. The QC rules check for various issues, such as incoming data format, volume minimums/maximums, vehicle classification comparisons, atypical days (holidays or special events), etc. Also, double-sided ATR stations are checked to ensure that both sides of the roadway are operational. A complete list of the Quality Control Rules for Continuous Monitoring Sites can be viewed in Table 1 on the following page: \n \n2013 Traffic Monitoring Program \n \n13 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTable 1: Quality Control Rules for Continuous Monitoring Sites \n \nQuality Control Rule \n \nDescription \n \nAll Counts/ One Bin \n \nThe system will reject the data if all the traffic for one vehicle class bin is in one lane for the day. \n \nMaximum Threshold \n \nAtypical Day or Holiday \nClass 1 Greater than Class 2 \n \nThe system will accept data that would have been marked as flagged based upon a predetermined list of atypical days or holidays. It will not accept incomplete data. The system will flag any day(s) where the volume in vehicle class 1 exceeds the volume in vehicle class 2. \n \nClass 14 Exceeds X \n \nThe system will flag the day(s) that have vehicles in class 14 greater than X percent of the total volume. \n \n0.7% \n \nClass 15 Exceeds X \n \nThe system will reject the day(s) that have vehicles in class 15 greater than X percent of the total volume. \n \n0.7% \n \nClass 3 Greater than Class 2 \n \nThe system will flag any day(s) where the volume in vehicle class 3 exceeds the volume in vehicle class 2. \n \nClass 8 Greater than Class 9 \n \nThe system will flag any day(s) where the volume in vehicle class 8 exceeds the volume in vehicle class 9. \n \nDaily Directional Volume The system will flag the entire set of counts if volume in one \n \n70% \n \nCheck \n \ndirection is over X percent of the total volume. This check is \n \nnot applied to non- directional data. \n \nDaily Ratio of Class 2 to The system will flag any day(s) where the daily total of vehicle \n \n56% \n \nDaily Total \n \nclass 2 data is greater than X percent of the total volume. \n \nLess than 24 Hours of Data \n \nThe system will reject any blank volume in one direction. \n \nMax Zeros \n \nThe system will reject the data if there are more than X \n \n7 \n \nconsecutive hours of zeros. \n \nMissing Lane Data \n \nThe system will reject the data if there are no vehicle counts \n \nduring the day for a lane or not enough data records have \n \nbeen provided. There should be one data record for each hour \n \nfor each lane defined in the incoming data. \n \nMulti-Unit Wait \n \nThe system will assign the ATR unit that has data (double-side \n \nsites only) with the temporary status of MULTI_UNIT_WAIT \n \nuntil data for the 2nd side is received. \n \nSum of Combination \n \nThe system will flag any day(s), where the total of the volumes \n \nVehicles Exceeds Class 9 in vehicle classes, 11, 12, and 13 exceeds the volume in vehicle \n \nclass 9. \n \nZero Bound \n \nThe system will reject any day that has an hour with zero \n \n50 \n \nvehicles that has the immediate hour before and after the zero \n \nwith a volume over X vehicles. \n \n2013 Traffic Monitoring Program \n \n14 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nWeekly Data Processing for Short-Term Monitoring Sites Portable traffic data collected by field technicians is processed on a daily or weekly basis by office personnel. Counties are closed out as the portable data collection is completed. Refer to Appendix E: Georgia Counties and Federal Information Processing Standards (FIPS) Identification Numbers for a list of counties. \n \nPortable traffic collection is tracked and monitored. In Figure 2, 54% of the portable traffic collected has passed quality control (indicated in green); 2% has failed, has been marked uncountable or is parked (indicated in yellow); and 44% not been completed, yet (indicated in red). This is a typical status for May. \n \nAs discussed in section V. Short-Term Monitoring Program, GPS \n \ndata and Field Notes collected at every portable data collection site assist with the quality control of the traffic count. Regarding GPS, office personnel compare the offset measured in meters \n \nFigure 2: Status of 2012 Portable Traffic Collection as of 5/30/2012 \n \nbetween the current year and the last year of data collection. Recorded GPS data coordinates need to be \n \nwithin the assigned TC segment. \n \nIf incoming traffic data is flagged, office personnel perform further analysis, such as: evaluate GPS data coordinates, review the QC rule that the count has failed, view historical comparison for site, study trend analysis graphs, and compare traffic count data from adjacent sites. A complete list of the Quality Control Rules for Portable Data Collection can be viewed in Table 5. \n \nPortable counts can be assigned into different categories: passed, failed, uncountable, reviewed, assigned, \nQC/load error, parked, or not reviewed. If a count has failed, the office personnel can assign it to a parked category where it will wait until the 2nd count data comes in for comparison. One, none or both counts can \nbe accepted at that time. There is a comment box where reasons for the decision can be noted. A High Level Overview of the Portable QC Process is shown below in Figure 3: \n \nDetermine the Traffic Collection \nPlan \n \nNo, delete and reload \n \nCreate Maps, Assign Traffic Count Sites, and Program GPS \nUnits \n \nCollect Portable Traffic, GPS, Field Notes \n \nData uploaded to Application \n \nSuccessful upload \nYes \n \nQC Review of Failed Count \nQC Rules GPS/ Field Notes \nSpecial Event/ Holiday \nHistorical Data Trend Analysis \n \nFail, but reset is ordered \nFigure 3: High Level Overview of the Portable QC Process \n \nMarked as `Fail' in application \nNo \n \nYes \nOverride \nFail \n \nMarked as `Pass' in application \n \nPass/Fail QC \n \nPass \n \nand Reset?? \n \n2013 Traffic Monitoring Program \n \n15 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTable 2: Quality Control Rules for Short-Term Monitoring Sites Quality Control Description Rule Blank (No Data) The system will reject any blank volume in one direction. Check \n \nMinimum Maximum \n \nThreshold Threshold \n \n-- \n \n-- \n \nClass 14 \n \nThe system will flag the day(s) that have vehicles in vehicle \n \n-- \n \n5% \n \nclass bin 14 greater than X percent of the total daily \n \nvolume. \n \nClass 15 \n \nThe system will flag the day(s) that have vehicles in vehicle \n \n-- \n \n1% \n \nclass bin 15 greater than X percent of the total daily \n \nvolume. \n \nClass 3 greater The system will flag any day where the volume in vehicle \n \n-- \n \n-- \n \nthan Class 2 \n \nclass bin 3 exceeds the volume in vehicle class bin 2. \n \nDaily Directional The system will calculate the directional distribution (D Volume Check Factor) of the traffic. If the D Factor is greater than X \npercent, the counts are flagged. \n \n-- \n \n70% \n \nDaily Ratio of The system will compare the ratio of vehicle class 1 bin \n \n-- \n \n-- \n \nClass 1 to 2 \n \ndata to vehicle class 2 bin data. If class 1 is higher, the data \n \nfor the day will be flagged. \n \nDirection Check \nFactor AADT Outside Range \n \nThe system will check that the direction for the site is correct. The system should PASS a 0 (non-directional) OR a pair (1:3 OR 2:4) at every TC Number. It would NOT accept a lone direction or an incorrectly matched directional pair (example: North-1 and East-2). The system calculates the AADT based on the factor groups using daily, monthly, and axle factors. Then, the system compares the computed hourly AADT to the historical AADT and will flag sites that are outside the established volume group tolerances limits. \n \n-Variable \n \n-Variable \n \n2013 Traffic Monitoring Program \n \n16 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nQuality Control Rule Historical Volume Check for Portable \nHourly Zero Volume Check \n \nDescription \nThe system averages the last 3 years of the AADT history. If 3 years of data is not available, the system will average the last 2 years of the AADT history. If 2 years is not available, the system will use one year of AADT history. The data is flagged, if it is outside the volume group tolerance limits. The system will reject any hour with zero volume in one direction when the current AADT for the site is greater than 10,000. \n \nMinimum Maximum Threshold Threshold Variable Variable \n \n-- \n \n10,000 \n \nLess Than 48 The system should reject the entire set of counts if there \n \n-- \n \nHours of Data are not at least 48 hours of data. This means one or more \n \nrow(s) in a PRN file is missing. If a row has a blank PRN file, \n \nthe system still counts the row. \n \nMax Hourly \n \nThe system will reject the entire set of counts with an \n \n-- \n \nVolume \n \nhourly volume count of greater than X \n \n-5,000 \n \nMidnight/ Noon The system will reject the entire set of counts, if the \n \nCheck \n \nmidnight count is higher than the noon count. \n \n-- \n \n-- \n \nPeak Hours (6-9 a.m.) (3-6p.m.) \n \nThe system will reject the entire set of counts with an \n \n-- \n \nhourly volume count of zero between the hours of 6 a.m.  \n \n9 a.m. and 3 p.m.  6 p.m. when the functional class is not \n \nequal to 9 or 19. \n \nPortable Truck The system will calculate the truck percent by adding \n \n-- \n \nPercent \n \nvehicle class bins 4 - 14 for the day and dividing by the \n \ntotal daily traffic count. Incoming data will be flagged, if \n \nthe truck traffic is greater than X percent. \n \nSum of \n \nThe system will flag any day, where the total of the \n \n-- \n \nCombination volumes in vehicle class bins 11, 12 and 13 exceeds the \n \nVehicles \n \nvolume in vehicle class bin 9. \n \nExceeds Class 9 \n \nVolume Check The system will flag any incoming data if there is an hourly \n \n0 \n \nvolume count of greater than 9999. Allowable volumes are \n \nfrom 0 to 9999. \n \n-40% \n-9,999 \n \n2013 Traffic Monitoring Program \n \n17 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nX. ANNUAL DATA PROCESSING \n \nAnnual data processing is a cycle that involves planning, traffic data collection, quality control, traffic calculations, reporting and publishing. Planning begins in November. Portable traffic collection begins in mid-January and ends around mid-November. The comprehensive review of the annual traffic begins in January. Refer to Appendix F: Traffic Calculations for further detail on traffic calculations. Reporting and publishing is usually in February or March. The following is a list of tasks that are performed during Annual Data Processing: \n \nUpdate Systems and Report Traffic \n \nEstablish the Plan \n \nImplement the Plan \n \n1. Establish the Plan a. Review TC segmentation b. Review collection cycle for portable data c. Compare TPAS site information and \n \nCalculate Estimates/ \nFactors \n \nCollect Traffic \n \nplanned collection (Coverage List) \n \n2. Implement the Plan \n \nReview Annual Traffic \n \na. Synchronize the Coverage List and TPAS \n \nb. Create lists of portable traffic count \n \nFigure 4: High Level Overview of \n \nAnnual Data Processing \n \nlocations for field technicians and consultants \n \n3. Collect Traffic a. Collect and review (QC) portable data, including GPS Data and Traffic Data Files b. Poll and review(QC) ATR data \n \n4. Review Annual Traffic a. Ensure all portable and continuous traffic has been collected and has passed quality control standards \n \n5. Calculate Estimates/ Factors a. Calculate traffic adjustment factors b. Estimate AADTs at uncounted TC sites based upon historical data and current year ATR data c. Calculate traffic on high volume roads (Step Down Method) d. Estimate traffic on local roads e. Calculate peak hour traffic data and K-factors \n \n6. Update Systems and Report Traffic a. Populate the Federal Reporting Enhanced Database with traffic data b. Provide traffic data for external public viewing (GA STARS and ATR Reports) c. Report traffic data to the FHWA in the HPMS submittal \n \n2013 Traffic Monitoring Program \n \n18 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nManagement of Traffic Count Segments According to the HPMS Field Manual, \"Selection of count station locations should be based on previous count experience, recent land developments, and the existence of uncounted sections along the routes.\" Although TC segments were initially created to be homogenous (i.e., similar traffic for the entire segment); traffic has a fluid dynamic and, as such, updates must be made annually in order to maintain the integrity of the segments. Break points are added, deleted, or moved to reflect changes reported in the road inventory and actual field conditions. \nOTD evaluation criteria for adding and spacing TC segments are as follows:  TC segments must meet Federal-aid eligibility requirements. Federal-aid roadways are any public road with a functional classification higher than a local road or rural minor collector. Local roads are randomly sampled for traffic data reporting; meaning only select locations on local roads have TC numbers. \n Typically, and wherever possible, segments should span from major intersection to a major intersection or a major traffic generator. A major intersection is defined as an arterial roadway. An example of a major traffic generator is an entrance/exit to a major retail store, such as a Super Wal-Mart. \n The Data Administration Group's office personnel evaluate a road's segmentation if adjacent AADT volumes are varying by 20% or more. In connection with this effort, the last three or more years of traffic history is considered during the analysis. \n New business requirements may require additional TC segments. For example, OTD added traffic count segments containing bridges to the coverage program in 2009. \nOTD evaluation criteria for retiring a TC segment are as follows:  If there is a re-classification in functional classification which makes the road a local road without the presence of a bridge or railroad, the TC number would be retired. \n Also, OTD reviews and evaluate sample sites if adjacent segments have less than 5% difference in the AADT volumes. If the evaluation process supports a modification, OTD will delete a sample and expand the terminus of the adjacent TC segment. \n Additionally, there could be a change in Federal requirements or funding levels. \n There may also be cases where it is not safe or feasible for a field technician to collect the data. \n \n2013 Traffic Monitoring Program \n \n19 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nCalculation of Traffic on High Volume Roads (Step Down Method) \n \nGDOT uses the ramp counting \n \nprocedure described in FHWA's TMG to estimate AADT volumes \n \nATR \n \nfor Interstates and freeways. It is \n \nreferred to as the Step Down \n \nTraffic Count 0927 \n \nMethod, which is also known to some states as Ramp Balancing. The \n \n8,179 \n \n-- \n \n+ \n \n7,915 \n \nAADT: 71,357 \n \nhigh volumes on these roads make \n \nthem impossible to collect with a \n \nportable collection device due to the \n \n-- \n \nsafety of the field crew. For example, the main Interstate through \n \n4,604 \n \n+ \n \n5,842 \n \nAtlanta, I-75, has an AADT (2012) \n \nTraffic Count 0371 \n \nof 336,490, and ramps at the I-285 \n \nCalculated AADT: 67,442 \n \nand I-85 interchange in DeKalb County (also known as Spaghetti \n \n7,268 \n \n-- \n \n+ \n \n8,153 \n \nJunction) have AADTs (2012) from \n \n6,000 to 45,000. \n \n-- \n \n+ \n \nThe Step Down Method involves counting all entrance and exit ramps between two established mainline anchor points (or nodes) and then reconciling the count data to calculate the mainline AADT. As shown in Figure 5: Example of Step Down Method, the calculated AADTs reduce in volume or `step down' from TC0927 to TC0446. The ramps are counted using either portable collection devices or, in a few locations, PTMS sites. OTD makes every effort to use ATR sites as nodes. \nAn AADT for each uncounted mainline link is calculated by addition or subtraction of ramp AADT (multiplied by an adjustment factor) to or from mainline AADT, starting from one anchor point/node. The allocation of the volume difference to the ramps (and subsequently to the mainline volume estimates) is carried out by proportionally distributing the volume difference remaining at the ending control point to each of the ramps. The adjustment to each \n \n5,012 \n \n4,922 \n \n675 \n \nTraffic Count 0369 \n \nCalculated AADT: 63,608 \n \n8,256 \n \n9,502 \n \n-- \n \n+ \n \n-- \n \n+ \n \n3,295 8,373 \n \n3,163 8,747 \n \nTraffic Count 0367 Calculated AADT: 53,885 \n \n-- \n \n+ \n \n+ \n \n-- \n \n2,416 \n \n2,267 \n \nTraffic Count 0446 AADT: 42,869 \n \n-- \n \nATR \n \nLegend Exiting Traffic \nEntering Traffic + \n \nFigure 5: Example of Step Down Method \n \n2013 Traffic Monitoring Program \n \n20 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nramp is computed as the ratio of the difference in volume (remaining at the end of the reconcilement) to the sum of the ramp volumes. \nIn the past, the process was time-consuming and labor intensive, because it was performed manually. Currently, the processing for the Step Down Method is calculated using a computer program after the AADTs have been calculated for the ATR sites. OTD does not calculate the AADT volumes derived by the Step Down Method by direction of travel. \n \n2013 Traffic Monitoring Program \n \n21 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTraffic Count Collection and Estimation on Local Roads According to the FHWA, \"States are required to report annually to the Federal Highway Administration (FHWA) aggregate estimates of VMT on the rural minor collector and local functional systems in rural, small urban and urbanized areas.\" Collectively, these are referred to as local roads which have similar travel characteristics such as: providing direct access to adjacent land, providing service to travel over short distances as compared to higher classification categories, linking locally important traffic generators with their rural hinterlands, etc. Examples of local roads are a subdivision road or an unpaved country road. Generally, except for the local roads, OTD collects traffic data on all types of roads in Georgia. \nOn local roads, OTD collect a small number of samples to derive and compute VMT statistics for Federal reporting purposes. The total local road mileage is approximately 90,373 miles, as of the revision date of this document (December 2013). OTD has exceeded the HPMS sampling requirements with the total number of collected local traffic counts ranging from 800-1600 for the past several years. \nAccording to the HPMS Field Manual, \"Statistically speaking, a universe is a population from which a sample is taken. A population can be any set of sampling units, such as objects that can be observed or people who can be surveyed. A sampling frame is a list of all the sampling units in a universe.\" In our case, the universe for local roads is the total local road mileage. The sampling unit is a randomly selected local road segment stratified by six local road types: Urban Local  Not Atlanta, Urban Local  Atlanta, Small Urban Local, Rural  Paved, Rural  Unpaved, and Dead-end/ Cul-de-sac. \n \n2013 Traffic Monitoring Program \n \n22 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTraffic Adjustment Factors Federal Regulations 23 CFR 500.204 states, \"The procedures used by a state to edit and adjust highway traffic data collected from short-term counts at field locations to estimates of average traffic volume shall be documented.\" The raw hourly counts from portable traffic collection devices for a 48-hour period are adjusted by monthly, daily and axle factors to determine the AADT. Factors are used to estimate `average' conditions and to account for variability in the traffic stream. They are based on data provided by the ATRs and are currently calculated annually in TPAS. \n \nMonthly factors are calculated by dividing the AADT by the monthly average daily traffic (MADT) for each location. In Georgia, January is usually the month with the lowest traffic volumes. Therefore, portable traffic collected in January would have the highest monthly factors. \n \nDaily or day-of-the-week factors are calculated by dividing the AADT by the average daily traffic (ADT). Typically, the day of the week with the lowest traffic volumes is Sunday which consequently has the highest daily factors. \n \nAxle correction factors are developed based on data that represents all seasons of the year. The axle correction factors are applied to raw counts taken with portable traffic counters which register two axle impacts as one vehicle. It is used to account for vehicles with more than two axles, typically trucks with three or more axles, in the traffic stream on a particular type of road. They should be applied to all counts that are based on axle sensors. Rural Interstates have the lowest axle factors, because they have the highest percentage of truck traffic in Georgia. \n \nOTD plans to review our factoring approach every year based upon a variety of factors: additional ATR sites that are installed, traffic trends/patterns, high growth areas, truck traffic patterns, etc. The ATRs are currently grouped into 16 traffic factor groups (refer to Table 6: Factor Groups). As expected, Atlanta has significantly different traffic patterns compared to the rural areas of the state. The 2012 factors are shown in the following tables: \n \nTable 3: 2012 Axle Factors \n \nFactor \n \nAxle Factors \n \nGroup* \n \n1 \n \n0.97 \n \n2 \n \n0.94 \n \n3 \n \n0.91 \n \n4 \n \n0.78 \n \n5 \n \n0.80 \n \n6 \n \n0.78 \n \n7 \n \n0.99 \n \n8 \n \n0.96 \n \n9 \n \n0.89 \n \n10 \n \n0.99 \n \n11 \n \n0.98 \n \n12 \n \n0.97 \n \n13 \n \n0.98 \n \n14 \n \n0.99 \n \n15 \n \n0.94 \n \n16 \n \n0.87 \n \n*Factor Groups are described in Table 6: Factor Groups. \n \n2013 Traffic Monitoring Program \n \n23 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTable 4: 2012 Daily Factors \n \nFactor \n \nSun Mon Tues Wed Thu Fri Sat \n \nGroup* \n \n1 \n \n1.27 1.00 0.98 0.97 0.94 0.88 1.05 \n \n2 \n \n1.30 0.99 0.97 0.96 0.93 0.87 1.07 \n \n3 \n \n1.21 1.02 1.01 1.00 0.95 0.85 1.03 \n \n4 \n \n0.99 1.09 1.12 1.08 0.98 0.85 0.95 \n \n5 \n \n0.99 1.07 1.10 1.07 0.99 0.84 0.99 \n \n6 \n \n0.95 1.08 1.14 1.10 0.99 0.82 0.99 \n \n7 \n \n1.27 0.98 0.97 0.93 0.93 0.89 1.12 \n \n8 \n \n1.37 0.99 0.97 0.96 0.93 0.85 1.06 \n \n9 \n \n1.24 1.00 0.99 0.98 0.93 0.86 1.08 \n \n10 \n \n1.38 0.95 0.93 0.92 0.91 0.89 1.18 \n \n11 \n \n1.47 0.96 0.94 0.93 0.91 0.86 1.12 \n \n12 \n \n1.46 0.98 0.94 0.94 0.92 0.86 1.10 \n \n13 \n \n1.42 0.97 0.94 0.93 0.92 0.88 1.10 \n \n14 \n \n1.36 1.00 0.96 0.94 0.92 0.88 1.06 \n \n15 \n \n1.23 0.99 0.98 0.96 0.93 0.90 1.06 \n \n16 \n \n1.35 0.97 0.95 0.94 0.91 0.87 1.12 \n \nTable 5: 2012 Monthly Factors \n \nFactor Group* Jan Feb Mar Apr Ma Jun Jul Aug Sep Oct Nov Dec \n \ny \n \n1 \n \n1.06 1.01 0.95 0.98 0.97 1.00 1.03 1.00 0.99 0.96 1.01 1.06 \n \n2 \n \n1.06 1.01 0.96 0.98 0.98 1.00 1.03 1.00 1.00 0.97 0.99 1.04 \n \n3 \n \n1.10 1.04 0.99 0.99 0.98 0.96 0.97 1.00 1.01 0.95 1.00 1.06 \n \n4 \n \n1.16 1.06 0.91 0.97 1.00 0.89 0.89 1.05 1.12 1.02 0.99 1.04 \n \n5 \n \n1.18 1.09 1.02 0.99 0.98 0.92 0.90 0.97 1.02 1.01 0.98 1.00 \n \n6 \n \n1.19 1.09 0.98 0.95 0.97 0.90 0.89 1.00 1.05 1.01 1.00 1.04 \n \n7 \n \n1.01 0.99 0.95 0.99 0.97 1.02 1.03 0.98 1.00 1.00 1.02 1.03 \n \n8 \n \n1.06 0.98 0.96 0.99 0.98 0.99 1.01 1.00 1.02 1.00 1.00 1.02 \n \n9 \n \n1.08 1.01 0.95 0.98 0.98 0.97 0.98 1.01 1.04 1.00 1.00 1.03 \n \n10 \n \n1.04 0.99 0.95 0.98 0.97 1.02 1.05 0.99 1.00 0.97 1.00 1.05 \n \n11 \n \n1.03 0.95 0.95 0.98 0.98 1.02 1.06 0.99 1.00 0.99 1.00 1.06 \n \n12 \n \n1.05 0.98 0.97 0.98 0.99 1.00 1.03 1.00 1.00 1.02 1.00 1.00 \n \n13 \n \n1.07 1.00 0.97 0.99 0.99 1.00 1.02 0.97 0.98 1.01 1.01 1.01 \n \n14 \n \n1.06 1.00 0.98 0.99 0.99 1.00 1.03 0.98 0.99 1.01 1.00 0.98 \n \n15 \n \n1.07 1.02 0.99 0.99 0.99 0.98 0.98 0.99 1.00 1.00 1.01 1.01 \n \n16 \n \n1.09 1.00 0.97 0.99 0.99 0.97 0.99 0.99 1.00 1.03 1.02 1.01 \n \n*Factor Groups are described in Table 6: Factor Groups. \n \n2013 Traffic Monitoring Program \n \n24 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nTable 6: Factor Groups No. Factor Group \n \n1 \n \nRural - Local Collectors \n \n2 \n \nRural - Minor Arterial \n \n3 \n \nRural - Major Arterial \n \nDescription \nLocal roads or collectors in a rural area which provide low levels of travel mobility (e.g., a subdivision road or intracounty travel corridor) Routes which provide service to corridors with trip lengths and travel densities greater than that of collectors or local roads (e.g., Appling County SR-15) Routes which have a trip length and travel density indicative of substantial state wide travel (e.g., Bartow County SR-20) \n \n4 \n \nRural - I-75 \n \nI-75 Outside of an Urban Area \n \n5 \n \nRural - I-85 \n \nI-85 Outside of an Urban Area \n \n6 \n \nRural - Interstates \n \nInterstates that are accessed only using ramps and are outside of an Urban Area (e.g., I-16 in Bryan County) \n \n7 \n \nSmall Urban - Local Collector \n \nLocal roads or collectors in a small urban area which provide \n \nlow levels of travel mobility (e.g., a subdivision road or intra- \n \ncounty travel corridor) \n \n8 \n \nSmall Urban - Arterial \n \nRoutes of moderate to high lengths and travel that are \n \nwithin a small urban area (e.g., Bulloch County SR-67 \n \nBypass) \n \n9 \n \nSmall Urban/Urban - Freeways Freeways, Expressways and Interstates which are restricted \n \nInterstate (Not Atlanta) \n \naccess roadways and not in Atlanta (e.g., I-95) \n \n10 \n \nUrban - Local Collector \n \nLocal roads or collectors in an urban area which provide low \n \nlevels of travel mobility (e.g., a subdivision road or intra- \n \ncounty travel corridor) \n \n11 \n \nUrban - Minor Arterial \n \nRoutes that serve the major centers of activity with the \n \n(Not Atlanta) \n \nhighest traffic volumes and the longest trip lengths not in \n \nAtlanta (e.g., Catoosa SR-146) \n \n12 \n \nUrban - Major Arterial \n \nRoutes that serve the major centers of activity with the \n \n(Not Atlanta) \n \nhighest traffic volumes and the longest trip lengths not in \n \nAtlanta (e.g., Catoosa SR-146) \n \n13 \n \nUrban - Minor Arterial (Atlanta) Routes which provide trips of moderate length linking \n \nprincipal arterials in Atlanta (e.g., Fulton County SR-3) \n \n14 \n \nUrban - Major Arterial (Atlanta) Routes that serve the major centers of activity with the \n \nhighest traffic volumes and the longest trip lengths in \n \nAtlanta (e.g., Cobb County SR-5) \n \n15 \n \nUrban - Freeways Interstate \n \nFreeways, Expressways and Interstates which are restricted \n \n(Atlanta) \n \naccess roadways and are in Atlanta (e.g., I-75, I-85, SR-400, \n \nI-985) \n \n16 \n \nUrban - I-285 (Atlanta) \n \nI-285 Loop \n \n2013 Traffic Monitoring Program \n \n25 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nXI. OTHER CONSIDERATIONS \n \nA complete analysis of any program identifies and considers all relevant issues and challenges. The main program management challenge is balancing costs, resources, and statistical data needs. In a world not constrained by funding or other resources, every TC segment on every road would have actual traffic data count available every year. Perhaps, in a small geographical area with a large budget this is an actual possibility. However, as is the case with most state Department of Transportations, budget constraints must be continually balanced with resources (time and available staff) and the needs (quantity and quality of traffic counts collected). It is the classic paradox of project management. \n \nCosts \n \nResources \n \nNeeds \n \nDespite budget constraints, the demand for traffic data in all formats has not been reduced. For example, the most recent HPMS reassessment is requiring additional traffic data to be collected on ramps. Special requests for traffic counts are also a competing factor with the portable traffic count program. Often, these traffic counts revolve around a special event and are not valid for use in an AADT calculation. As previously mentioned, OTD has also added traffic counts specifically located near bridges to meet internal data needs. \n \nOther challenges include relational database struggles, software integration, staffing issues, and making traffic data accessible to the public in an easy-to-use interface. Most of the traffic data customers want an easy-to-use, simple interface that provides traffic counts. Other customers want all types of traffic data in detail as soon as it is available to them. OTD has made significant strides towards making data more accessible to the public and is continually exploring how to better serve customers. \n \nIn regards to traffic data collection, safety of the traffic data collection crew is the primary concern in collecting data on high-volume routes. Due to equipment failures, collecting traffic data in stop-and-go traffic conditions is a challenge. Increased traffic congestion increases the difficulty in obtaining reliable vehicle classification counts. Construction and incidents also impact traffic data collection activities. Data processing, and quality control and assurance are challenges especially for high traffic-volume routes. Atlanta, in particular, as a metropolitan area with approximately five million people has significant traffic congestion, construction, and traffic incidents. \n \n2013 Traffic Monitoring Program \n \n26 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nREFERENCES \nAmerican Association of State Highway and Transportation Officials (AASHTO), United States. (2009). AASHTO Guidelines for Traffic Data Programs. \nFederal Regulations, Title 23: Highways, Part 500-Management and Monitoring Systems, Subpart BTraffic Monitoring Systems, 500.201-204. Retrieved April 10, 2012 from http://ecfr.gpoaccess.gov/cgi/t/text/textidx?c=ecfr\u0026rgn=div5\u0026view=text\u0026node=23:1.0.1.6.14\u0026idno=23 \nGeorgia Department of Transportation, Office of Transportation Data. (June 2008). Traffic Data Collection Guide. \nNational Cooperative Highway Research Program, Transportation Research Board, National Research Council. (2008). Mechanistic-Empirical Pavement Design Guide of New and Rehabilitated Pavement Structures. Retrieved April 30, 2012, from http://onlinepubs.trb.org/onlinepubs/archive/mepdg/home.htm \nRandall, James L. (February 1, 2012). Texas Department of Transportation, Traffic Recorder Instruction Manual. Retrieved April 30, 2012 from http://onlinemanuals.txdot.gov/txdotmanuals/tri/images/FHWA_Classification_Chart_FINAL.png \nU.S. Department of Transportation, Federal Highway Administration, Office of Highway Policy Information. (March 2012). Highway Performance Monitoring System Field Manual. \nU.S. Department of Transportation, Federal Highway Administration, Office of Highway Policy Information. (Update: April 4, 2013). Traffic Monitoring Guide. Retrieved November 20, 2013 from http://www.fhwa.dot.gov/policyinformation/tmguide/. \n \n2013 Traffic Monitoring Program \n \n27 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nAppendix A: FHWA 13-Bin Vehicle Classification Scheme \n \nSource: Texas Department of Transportation's illustration of the FHWA 13-Bin Vehicle Classification Scheme \n \n2013 Traffic Monitoring Program \n \n28 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nAppendix B: 2011 to 2013 Portable Traffic Collections \n \nTable B-1: 2011 Portable Traffic Collections (Planned) \n \nRoad System \n \nCycle \n \nVolume Only Traffic Counts \n \nState Routes \nOff-System Federal - \nAid \nNon Federal-Aid Locals2 Critical Ramps3 Major Ramps4 Other Ramps5 \n \n2 Year 4 Year \n6 Year \nAnnual 2 Year 4 Year \n \n2,100 1,700 \n1,300 \n615 350 250 \n \nClassification Traffic Counts \n1,989 2981 \n200 \n---Total \n \nPTMS Counts \n11 2 \n35 \n \nTotal Traffic Counts 4,100 2,000 \n1,500 \n650 350 250 8,850 \n \nTable B-2: 2012 Portable Traffic Collections (Planned) \n \nRoad System \n \nCycle \n \nVolume Only Traffic Counts \n \nState Routes \nOff-System Federal- \nAid \nNon Federal-Aid Locals2 Critical Ramps3 Major Ramps4 Other Ramps5 \n \n2 Year 4 Year \n6 Year \nAnnual 2 Year 4 Year \n \n2,367 1,623 \n1,034 \n615 350 244 \n \nClassification Traffic Counts \n1,629 3711 \n359 \n--6 \n \nPTMS Counts \n11 2 \n-- \n35 --Total \n \nTotal Traffic Counts 4,007 1,996 \n1,393 \n650 350 250 8,646 \n \nTable B-3: 2013 Portable Traffic Collections (Planned) \n \nRoad System \n \nCycle \n \nVolume Only Traffic Counts \n \nState Routes Off-System FederalAid Non Federal-Aid Locals2 Ramps \n \n2 Year 4 Year \n6 Year \nMixed \n \n1,878 1,487 \n1,184 \n1,315 \n \nClassification Traffic Counts \n2,178 3321 \n529 \n-- \n \nPTMS Counts \n11 2 \n-- \n35 Total \n \nTotal Traffic Counts 4,067 1,821 \n1,713 \n1,350 8,951 \n \n2013 Traffic Monitoring Program \n \n29 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nFootnotes: \n1. The Off-System Federal-aid vehicle classification counts are on offsystem HPMS sample locations and National Highway System (NHS) Intermodal facilities. \n2. Non Federal-aid local counts include counts taken near bridges and railroads. 3. The ramp program will be divided into its own program based on priority to step-down, urban areas, and HPMS needs. \nCritical ramp interchanges are defined as the following: a. Interstate-to-Interstate b. Interstate-to-Freeway c. Strategic Atlanta Exits/Interchanges (High Volume Corridors): I-285, Inside Perimeter, I-85 in Gwinnett, I-75 in Cobb, \nand GA-400 in Fulton 4. Major ramp interchanges are defined as the following: \na. Other Atlanta Urbanized Area Boundary Interchanges b. I-95, I-516, I-520 Locations (Not Already in Critical Ramp Category) c. Other Step-down Interchanges 5. Other ramp interchanges are defined as the following: a. All other Step Down interchanges (rural locations) b. All other HPMS qualifying ramps not used in Step Down calculations \n \n2013 Traffic Monitoring Program \n \n30 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nAppendix C: Permanent Weigh-In-Motion Sites \n \nNo. \n \nSite ID \n \nWIM Lanes1 Location \n \n1 \n \n021-0334 \n \n1N \n \nI-75/SR 401 between I-475 and SR 247 \n \n021-0334 \n \n1S \n \nI-75/SR 401 between I-475 and SR 247 \n \n2 \n \n039-0218 \n \n1N \n \nI-95/SR 405 between the Florida State Line and St. Marys \n \nRoad (Camden County) \n \n039-0218 \n \n1S \n \nI-95/SR 405 between the Florida State Line and St. Marys \n \nRoad (Camden County) \n \n3 \n \n051-0368 \n \n2E/2W I-16/SR 404 0.6 miles east of SR 307 Dean Forest Road \n \n4 \n \n065-0118 \n \n1E/1W US 84/SR 38 north of Leland Smith Road, Homerville (Clinch \n \nCounty) \n \n5 \n \n067-2373 \n \n4N \n \nI-285/SR 407 at Orchard Road between mile post 16 and 17 \n \n(Cobb County) \n \n6 \n \n081-0347 \n \n1N/1S \n \nSR 300 west of Culpepper Road between mile post 10 and 11, \n \nCordele (Crisp County) \n \n7 \n \n127-0312A \n \n2N \n \nI-95/SR 405 between SR 27 and Golden Isles Parkway (SR 25 \n \nSpur) \n \n127-0312B \n \n1S \n \nI-95/SR 405 between SR 27 and Golden Isles Parkway (SR 25 \n \nSpur) \n \n8 \n \n143-0126 \n \n1E/1W I-20/SR 402 at the Alabama State Line between mile post 0 \n \nand 1 (Haralson County) \n \n9 \n \n185-0227 \n \n1N \n \nI-75/SR 401 between the Florida State Line and Lake Park \n \nBellview Road (Lowndes County) \n \n185-0227 \n \n1S \n \nI-75/SR 401 between the Florida State Line and Lake Park \n \nBellview Road (Lowndes County) \n \n10 \n \n207-0222 \n \n2N/2S \n \nI-75/SR 401 between Pate Road and Bibb County Line, Macon \n \n(Monroe County) \n \n11 \n \n245-0218 \n \n1E/1W I-20/SR 402 between SR 104 and South Carolina State Line \n \nFootnotes: 1. N=North, S=South, E=East, and W=West \n \n2013 Traffic Monitoring Program \n \n31 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nAppendix D: Portable Weigh-In-Motion Sites \n \nNo. \n \nSite ID \n \nLocation \n \n1 \n \n027-0138 US 84/SR 38 east of Boston near Pidcock Road (CR 91) (Brooks County) \n \n2 \n \n031-0187 US 301/SR 73 towards town just north of SR 46 \n \n3 \n \n051-0350 SR 307 just outside Garden City Terminal main gate (Chatham County) \n \n4 \n \n057-0239 I-575 just south of Sixes Road interchange (Exit 11) (Cherokee County) \n \n5 \n \n059-0125 US 129/SR-15 Alternate, just north of the Athens Perimeter between \n \nHomewood Drive and Trinity Place (Clarke County) \n \n6 \n \n071-0006 SR 133 southeast of Moultrie near Culbertson Road (Colquitt County) \n \n7 \n \n089-3112 SR 42 (Moreland Avenue) just north of I-285 (DeKalb County) \n \n8 \n \n089-3205 SR 155 just southeast of I-285 near Columbia Drive (DeKalb County) \n \n9 \n \n097-0045 SR 6 north of I-20 near Oak Ridge Road (Douglas County) \n \n10 \n \n097-0323 SR 6 south of I-20 near Factory Shoals Road (Douglas County) \n \n11 \n \n099-0047 US 84/SR 38 west of Donalsonville and east of Jakin near Harrell Moye Road \n \n(Early County) \n \n12 \n \n107-0022 US 1/SR 4 north of Swainsboro near Hawhammock Church Road (Emanuel \n \nCounty) \n \n13 \n \n115-0087 US 411/SR 53 west of Cave Springs near Buttermilk Road (Floyd County) \n \n14 \n \n121-5716 SR 6 just west of I-285 near Welcome All Road \n \n15 \n \n151-0103 SR 155 just north of Bill Gardner Parkway/Hampton Locust Grove Road (Henry \n \nCounty) \n \n16 \n \n157-0245 US 129/SR 11 just east of I-85 Interchange (Jackson County) \n \n17 \n \n171-0127 US 41/SR 7, 2.3 miles north of town \n \n18 \n \n179-0041 US 84/SR 38 in Walthourville just east of SR 119 (Liberty County) \n \n19 \n \n189-0003 US 78/SR 10 just north of SR 43/Lincolnton Road (McDuffie County) \n \n20 \n \n199-0212 SR 109 west of Greenville between Highpoint Road and Fire Tower Road \n \n(Meriwether County) \n \n21 \n \n219-0258 SR 316 just west of US 78/SR 10 interchange near Caterpillar Plant (Oconee \n \nCounty) \n \n22 \n \n223-0103 SR 6 west of Dallas near Gold Mine Road (Paulding County) \n \n2013 Traffic Monitoring Program \n \n32 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nNo. \n \nSite ID \n \nLocation \n \n23 \n \n227-0237 SR 5/515, 0.3 miles north of SR 108 at mile post 12.85 \n \n24 \n \n229-0123 US 84/SR 38 southwest of Patterson near Aaron's Way (Pierce County) \n \n25 \n \n241-0052 US 441/SR 15 south of SR 246 near the State Line (Rabun County) \n \n26 \n \n245-0132 SR 56 (Mike Padgett Highway) north of Hephzibah-McBean Road (Richmond \n \nCounty) \n \n27 \n \n255-0373 SR 16 between South McDonough Rd and High Falls Rd \n \n28 \n \n269-0138 SR 96 west of Butler between McCall Road (CR 239) and Back Road (CR 63) \n \n(Taylor County) \n \n29 \n \n285-0047 US 27/SR 1 just south of SR 54 north of LaGrange (Troup County) \n \n30 \n \n297-0018 SR 10 between Youth Monroe Rd and SR 10BU Alcovy River \n \n31 \n \n303-0001 SR 15 south of Sandersville between Montgomery Road and Harrison- \n \nRiddleville Road (Washington County) \n \n32 \n \n305-0041 US 341/SR 27 near River Road southeast of Jesup (Wayne County) \n \n33 \n \n319-0125 US 441/SR 29 just east of SR 112 near Thompson-Denson Road (Wilkinson \n \nCounty) \n \n34 \n \n321-0145 US 82/SR 520 near Summer between West Road and College Street (Worth \n \nCounty) \n \n2013 Traffic Monitoring Program \n \n33 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nAppendix E: Georgia Counties and FIPS Identification Numbers \n \nCounty \nAPPLING ATKINSON BACON BAKER BALDWIN BANKS BARROW BARTOW BEN-HILL BERRIEN BIBB BLECKLEY BRANTLEY BROOKS BRYAN BULLOCH BURKE BUTTS CALHOUN CAMDEN CANDLER1 CARROLL CATOOSA CHARLTON CHATHAM CHATTAHOOCHEE CHATTOOGA CHEROKEE CLARKE CLAY CLAYTON CLINCH COBB COFFEE COLQUITT COLUMBIA COOK COWETA CRAWFORD CRISP \n \nCode \n001 003 005 007 009 011 013 015 017 019 021 023 025 027 029 031 033 035 037 039 043 045 047 049 051 053 055 057 059 061 063 065 067 069 071 073 075 077 079 081 \n \nCounty \nDADE DAWSON DECATUR DEKALB DODGE DOOLY DOUGHERTY DOUGLAS EARLY ECHOLS EFFINGHAM ELBERT EMANUEL EVANS FANNIN FAYETTE FLOYD FORSYTH FRANKLIN FULTON GILMER GLASCOCK GLYNN GORDON GRADY GREENE GWINNETT HABERSHAM HALL HANCOCK HARALSON HARRIS HART HEARD HENRY HOUSTON IRWIN JACKSON JASPER JEFF-DAVIS \n \nCode \n083 085 087 089 091 093 095 097 099 101 103 105 107 109 111 113 115 117 119 121 123 125 127 129 131 133 135 137 139 141 143 145 147 149 151 153 155 157 159 161 \n \nCounty \nJEFFERSON JENKINS JOHNSON JONES LAMAR LANIER LAURENS LEE LIBERTY LINCOLN LONG LOWNDES LUMPKIN MCDUFFIE MCINTOSH MACON MADISON MARION MERIWETHER MILLER MITCHELL1 MONROE MONTGOMERY MORGAN MURRAY MUSCOGEE NEWTON OCONEE OGLETHORPE PAULDING PEACH PICKENS PIERCE PIKE POLK PULASKI PUTNAM QUITMAN RABUN RANDOLPH \n \nCode \n163 165 167 169 171 173 175 177 179 181 183 185 187 189 191 193 195 197 199 201 205 207 209 211 213 215 217 219 221 223 225 227 229 231 233 235 237 239 241 243 \n \nCounty \nRICHMOND ROCKDALE SCHLEY SCREVEN SEMINOLE SPALDING STEPHENS STEWART SUMTER TALBOT TALIAFERRO TATTNALL TAYLOR TELFAIR TERRELL THOMAS TIFT TOOMBS TOWNS TREUTLEN TROUP TURNER TWIGGS UNION UPSON WALKER WALTON WARE WARREN WASHINGTON WAYNE WEBSTER WHEELER WHITE WHITFIELD WILCOX WILKES WILKINSON WORTH \n \nCode \n245 247 249 251 253 255 257 259 261 263 265 267 269 271 273 275 277 279 281 283 285 287 289 291 293 295 297 299 301 303 305 307 309 311 313 315 317 319 321 \n \nFootnote: 1. Numbers 041 and 203 have been deliberately omitted. \n \n2013 Traffic Monitoring Program \n \n34 | P a g e \n \n Georgia DOT \n \nOffice of Transportation Data \n \nAppendix F: Traffic Calculations \n \nDescription Annual Vehicle Miles Traveled (AVMT) ATR AADT \nAxle Factors \nD or Directional Distribution Factor Daily Factors \nDaily Vehicle Miles Traveled (DVMT or VMT) K or Design Hour Factor \nMonthly Factors \nPortable AADT (Classification) Portable AADT (Volume Only) Simple Sample Size Calculation \nTruck Percentages \n \nEquation* Daily Vehicle Miles Traveled * 365 \nSum of Total Yearly Traffic Volume/ Total Number of Operational Days \nTotal Vehicle Volume / (Total Axle Strikes/ 2) \nPredominate Direction of Peak Hour Volume/ Total Peak Hour Volume \nAADT/ Average Daily Traffic \nLength of Roadway Segment * AADT 30th Highest Hour/ AADT \nAADT/ Monthly Average Daily Traffic \n24-hour Short-Term Volume * Daily Factor * Monthly Factor \n24-hour Short-Term Volume * Daily Factor * Monthly Factor * Axle Factor \nn= t x p(1-p) m \nDescription: n = Required Sample Size t = Confidence Level at 99% (Standard Value of 2.576) p = Population m = Margin of Error at 5% (Standard Value of 0.05) \n(Sum of Vehicles in Classes 4-13/ Total Sum of Vehicles) * 100 \n \nFootnotes: \n1. The list above is intended to be a basic list of equations. It should be noted that additional steps, such as summation or averaging, may be necessary before an equation listed above can be applied to the data. \n2. Data that has not been accepted based upon the established QC rules is omitted from any calculation. \n \n2013 Traffic Monitoring Program \n \n35 | P a g e \n \n "}],"pages":{"current_page":1,"next_page":null,"prev_page":null,"total_pages":1,"limit_value":10,"offset_value":0,"total_count":1,"first_page?":true,"last_page?":true},"facets":[{"name":"type_facet","items":[{"value":"Text","hits":1}],"options":{"sort":"count","limit":16,"offset":0,"prefix":null}},{"name":"creator_facet","items":[{"value":"Georgia. Department of Transportation. Division of Permits and Operations. 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