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1 Traffic data and AnalysisManualSeptember 2001 Traffic data and Analysis ManualSeptember 2001 Manual NoticesManual Notice 2001-1To:Districts, Divisions and OfficesFrom:Kirby W. Pickett, : Traffic data and Analysis ManualEffective Date:June 1, 2001 PurposeTo issue the Traffic data and Analysis Manual . This Manual is contained in the Planningand Programming Collection of the TxDOT Online Manual Traffic data and Analysis Manual contains the following chapters: Traffic Estimation and Forecasting Urban Travel Demand Forecasting Project Level Traffic data Development Database of the Transportation Planning Division Operations Manual dated April 4, remove and recycle the Transportation Planning Division Operations Manual datedApril 4, Traffic data and Analysis Manual will be distributed online only. Manual distributorsmay print and distribute a hardcopy from the PDF online version for employees not on theTxDOT wide-area-network or those preferring to retain a hardcopy.

2 In this case, manualdistributors must retain a distribution list and must also print and distribute all questions or suggestions to the Special Projects and Policy Analysis Branch of theAdministration Section of the Transportation Planning and Programming Division (TPP). Traffic data and Analysis Manual1-1 TxDOT 9/2001 Chapter 1 Traffic Estimation and ForecastingContents:Section 1 Overview .. 1-4 Section 2 Traffic data Collection and 3 Automatic Traffic Recorder Volume 1-6 ATR data Collection ..1-6 ATR data Analysis ..1-6 ATR data Reporting ..1-7 Section 4 Accumulative Count Recorder Traffic data .. 1-8 ACR data Collection ..1-8 ACR data data 5 Highway Performance Monitoring System Traffic data .. data Collection ..1-9 HPMS data Analysis ..1-9 HPMS data Reporting ..1-9 Section 6 Five Year Count Program .. Year Count data Year Count data Analysis ..1-10 Five Year Count data Reporting ..1-10 Section 7 Vehicle Classification 1-11 Vehicle Classification data Collection.

3 1-11 Vehicle Classification data Classification data 8 Truck Weigh-in-Motion data .. 1-13 Weigh-in-Motion data Collection ..1-13 Weigh-in-Motion data Analysis ..1-14 Weigh-in-Motion data Reporting ..1-14 Section 9 Vehicle Speed data .. 1-15 Vehicle Speed data Collection ..1-15 Vehicle Speed data Analysis ..1-15 Vehicle Speed data Reporting ..1-15 Section 10 Long-Term Pavement Performance data .. Pavement Performance data Collection ..1-16 Long-Term Pavement Performance data Pavement Performance data data and Analysis Manual1-2 TxDOT 9/2001 Section 11 Border Trend Traffic data .. Trend Traffic data Trend Traffic data Reporting ..1-19 Section 12 Traffic data for Special 1-20 Section 13 Off-System Traffic data .. 1-21 Off-System Traffic data Traffic data Analysis ..1-21 Off-System Traffic data Reporting ..1-21 Section 14 Permanent ATR Locations by 1-22 ATR 15 Vehicle Classification Count 1-29 Count Locations.

4 1-29 Section 16 Speed data Collection Sites .. 1-46 Speed Collection Sites ..1-46 Section 17 Long-Term Pavement Program Site 1-49 Pavement Program Sites ..1-49 Section 18 Texas 6 Vehicle Classification 1-53 Texas 6 Vehicle Classifications ..1-53 Section 19 FHWA Vehicle Classification Figures .. 1-56 FHWA Vehicle Classifications ..1-56 Chapter 1 Traffic Estimation andForecastingSection 1 OverviewTraffic data and Analysis Manual1-3 TxDOT 9/2001 Chapter 1 Traffic Estimation andForecastingSection 1 OverviewTraffic data and Analysis Manual1-4 TxDOT 9/2001 Section 1 OverviewTraffic estimation and forecasting involve Traffic data collection, Traffic estimates, andprojections based on historic Traffic data , corridor Analysis for projects, and urban traveldemand modeling. The process involves the Texas Department of Transportation (TxDOT),metropolitan planning organizations (MPOs), and local professionals use the results of Traffic data collection, estimation, andforecasting to develop transportation plans and programs; analyze project alternatives;complete environmental analyses; prepare roadway geometric, intersection, and pavementdesign; and select 1 Traffic Estimation andForecastingSection 2 Traffic data Collection andReportingTraffic data and Analysis Manual1-5 TxDOT 9/2001 Section 2 Traffic data Collection and ReportingOverviewTxDOT performs Traffic and other data collection programs on a continuous basis.

5 Datacollection programs include: automatic Traffic recorder volume data accumulative count recorder Traffic data highway performance monitoring system Traffic data five year count program vehicle classification data truck weigh-in-motion data vehicle speed data long-term pavement performance data border trend Traffic data The data are used to support the planning, design, and programming functions of TxDOT,MPOs, and local government 1 Traffic Estimation andForecastingSection 3 Automatic Traffic RecorderVolume DataTraffic data and Analysis Manual1-6 TxDOT 9/2001 Section 3 Automatic Traffic Recorder Volume DataATR data CollectionTPP collects Traffic data using permanent automatic Traffic recorder (ATR) equipment atapproximately 160 permanent sites (see Table 1-1 or Section 14 ) around the state. (To see amap of TxDOT districts, link to .) ATRlocations are selected by TPP and TxDOT districts in accordance with the FHWA TrafficMonitoring Guide (TMG) (accessible from a link on the TxDOT Internet ) and approved and implementedby ATRs collect data 24 hours a day, 365 days annually, for each lane.

6 The equipmentrecords Traffic volumes as total and as directional Traffic for each station. TPP retrieves thedata via modem daily, Monday through Sunday, to develop seasonal factors and estimatevehicle miles of travel (VMT).Table 1-1: Permanent ATR Locations by DistrictClick on district name to access location listing Abilene District Dallas District Paris District Amarillo District El Paso District Pharr District Atlanta District Fort Worth District San Angelo District Austin District Houston District San Antonio District Beaumont District Laredo District Tyler District Brownwood District Lubbock District Waco District Bryan District Lufkin District Wichita Falls District Childress District Odessa District Yoakum District Corpus Christi District ATR data AnalysisTPP analyzes hourly volumes and daily totals using historical patterns for variation factors developed by TPP are applied to accumulative count recorder(ACR) axle counts to develop average annual daily Traffic (AADT) figures.

7 StatewideVMT is estimated from these data . TPP also derives directional factors and K-factors fromthe data collected at each ATR 1 Traffic Estimation andForecastingSection 3 Automatic Traffic RecorderVolume DataTraffic data and Analysis Manual1-7 TxDOT 9/2001 ATR data ReportingTPP prepares monthly reports for each site. Monthly reports provide the actual hourlycounts and a percent variation in Traffic for each ATR site. Access to monthly reports ismade via the DOTS mainframe. The year-end report contains more detailed informationincluding annual average hourly volumes by days of the week, highest hours of the year,average daily Traffic by month, day and season, AADT percent variation by years, andAADT by year for each site. TPP produces annual reports in Excel 1 Traffic Estimation andForecastingSection 4 Accumulative Count RecorderTraffic DataTraffic data and Analysis Manual1-8 TxDOT 9/2001 Section 4 Accumulative Count Recorder Traffic DataACR data CollectionACR data collection includes short-term Traffic volume counts.

8 TPP makes or contracts outbetween 60,000 and 80,000 counts each year. TPP performs counts onHighway Performance Monitoring System (HPMS) samples and on-system roads annuallyand off-system counts on county roads and in urbanized areas on five-year cycles. TPPdetermines annual count locations and contractors perform the counts. Contractoracquisition of special counts such as turning movements and vehicle classification maybegin in FY2000. Additional Manual counts may be requested by TxDOT district offices bysubmitting a request form to data AnalysisAccumulative count recorders collect data in 24-hour samples that include all axles passinga point. TPP uses counted or estimated vehicle classification data at locations to determinethe axle-to-vehicle ratio for each axle count. ACR-recorded count volumes are convertedinto total number of vehicles using these data ReportingTypically, TPP maintains ten years worth of historic data to provide backgroundinformation.

9 Anyone who needs Traffic data may obtain information from TPP - Traffic orTPP - data 1 Traffic Estimation andForecastingSection 5 Highway Performance MonitoringSystem Traffic DataTraffic data and Analysis Manual1-9 TxDOT 9/2001 Section 5 Highway Performance Monitoring System Traffic DataOverviewThe HPMS (accessible from a link on the TxDOT Internet ) is a federally mandated programused by the Federal Highway Administration (FHWA) to provide data to Congress on thenation s streets and highways. Congress uses the data for allocation of funds to states. Everystate collects, maintains, and reports certain data to the FHWA each year according to themethods prescribed in the Highway Performance Monitoring System Field Manual (accessible from a link on the TxDOT Internet ) for the continuing analytical andstatistical data CollectionTxDOT uses the data and collection methods set forth in the HPMS Field Manual (accessible from a link on the TxDOT Internet ) and the FHWA TrafficMonitoring Guide.

10 The data are designed to provide an inventory of all on-system roads andother public roads that are functionally classified. Specific data collected under the HPMS program include location by jurisdiction, the number of lanes, median widths, shoulderwidths, and other basic road district offices collect, update, and submit the required information for roadwayswithin their district to TPP. The data are collected between September 1 and December 31each year and are submitted to TPP by December data AnalysisTxDOT uses the Texas Reference Marker System (TRM) database, which is a collection ofroadway information, to compile the HPMS data . District offices can access the database toview and modify information on specific data ReportingTxDOT prepares an annual report to FHWA on or before June 15th each year. The HPMSF ield Manual details how to prepare this 1 Traffic Estimation andForecastingSection 6 Five Year Count ProgramTraffic data and Analysis Manual1-10 TxDOT 9/2001 Section 6 Five Year Count ProgramOverviewThe five year count program (previously called urban saturation count program) consists ofmaking ACR Traffic counts throughout the 26 urbanized areas within Texas.