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The AADT file is a station point location of Annual Average Daily Traffic (AADT) estimates. This includes the data submitted to FHWA for Highway Performance Monitoring System (HPMS) AADT reporting for 2021. Data are reported for AADT on all highways with a Functional Classification (FC) above Local. A full coverage is provided for these routes where AADT segmentation is based on network configuration, travel patterns, and land use. The extent of highway this AADT represents has not been determined. An AADT is an Annual Average Daily Traffic volume for all lanes in both directions passing a point on the highway system. It represents the average of all days during the year with typical traffic conditions. An AADT estimate is generated using procedures that comply with the standards specified in the Traffic Monitoring Guide published by the Federal Highway Administration. There are over 44,000 AADT stations that provide traffic data history from 2002 to the current year. With these collection locations, Traffic Survey has adopted the following data collection schedule: Interstate route volumes are collected on an annual basis; US and NC route volumes are also collected on an annual basis except for stations that fall within the off-cycle urban areas. (See urban area cycle below.) Secondary Road (SR) volumes are collected on a biennial cycle with approximately half being counted each year. If a particular secondary road is not available for the most current year, it may be available for the prior year. North Carolina's eighteen largest urban areas are counted on a biennial cycle with 10 urban areas counted during the even years, and 8 urban areas counted during the odd years. The following urban areas are collected during the even year cycle: Asheville, Charlotte, Concord-Kannapolis, Fayetteville, Gastonia, Goldsboro, Greenville, and Jacksonville. The following urban areas are collected during the odd year cycle: Burlington, Chapel Hill, Durham, Greensboro, Hickory, High Point, Raleigh, Rocky Mount, Wilmington, and Winston-Salem. Data in this file derives from NCDOT Roads & Highways, Quarter 1 publication of the current calendar year. The referencing provided is based on the 2022 Quarter1publication of the NCDOT Linear Referencing System (LRS). Some differences will be found when using different quarterly publications with this data set. The data provided is seasonally factored to an estimate of an annual average of daily traffic. The statistics provided are Location_ID - 10-digit unique count location identifier, ROUTE: Numbered route identifier, or local name if not State maintained, LOCATION: Description of the Annual Average Daily Traffic station location.
AADT 2021: Estimated Annual Average Daily Traffic in vehicles per day for 2021 AADT_2018: Estimated Annual Average Daily Traffic in vehicles per day for 2018 AADT_2017: Estimated Annual Average Daily Traffic in vehicles per day for 2017 AADT_2016: Estimated Annual Average Daily Traffic in vehicles per day for 2016 AADT_2015: Estimated Annual Average Daily Traffic in vehicles per day for 2015 AADT_2014: Estimated Annual Average Daily Traffic in vehicles per day for 2014 AADT_2013: Estimated Annual Average Daily Traffic in vehicles per day for 2013 AADT_2012: Estimated Annual Average Daily Traffic in vehicles per day for 2012 AADT_2011: Estimated Annual Average Daily Traffic in vehicles per day for 2011 AADT_2010: Estimated Annual Average Daily Traffic in vehicles per day for 2010 AADT_2009: Estimated Annual Average Daily Traffic in vehicles per day for 2009 AADT_2008: Estimated Annual Average Daily Traffic in vehicles per day for 2008 AADT_2007: Estimated Annual Average Daily Traffic in vehicles per day for 2007 AADT_2006: Estimated Annual Average Daily Traffic in vehicles per day for 2006 AADT_2005: Estimated Annual Average Daily Traffic in vehicles per day for 2005 AADT_2004: Estimated Annual Average Daily Traffic in vehicles per day for 2004 AADT_2003: Estimated Annual Average Daily Traffic in vehicles per day for 2003 AADT_2002: Estimated Annual Average Daily Traffic in vehicles per day for 2002 Note: A value of zero in the AADT field indicates no available AADT data for that year. Please note the following: Not ALL roads have PTC stations located on them. Except for Interstate, NC and US routes, NCDOT County Maps refer to roads using a four-digit Secondary Road Number, not a road’s local name. If additional information is needed, or an issue with the data is identified, please contact the Traffic Survey Group at (919) 707-0936. Disclaimer related to the spatial accuracy of this file: This data cannot be construed to be a legal document.
The Traffic Segment Event file contains Annual Average Daily Traffic (AADT) and Vehicle Class (VC) estimates. This resource represents the approved annual submission to the FHWA, Highway Performance Monitoring System (HPMS) reporting for calendar year 2021. We report AADT on all highways functionally classified (FC) above Local. A full coverage is provided for routes where AADT segmentation is based on network configuration, travel patterns, and land use. Where divided highways occur, the AADT total for both directions is referenced on the inventory direction. Data is provided for ramps also. The ramp data does not cover all ramp segments, but all major traffic flows at interchanges are reported. Some maintained traffic segments require multiple records due to route ID changes at the county boundary in the linear referencing system (LRS). Traffic statistics for these segments are the same on each side of the county boundary but are maintained in this format to preserve the different location referencing data. Over 31,000 reference records (labeled “MAINT” in the SOURCE field) are required to provide event data for all maintained AADT segments. Supplemental AADT are provided on the routes that are Functionally Classified LOCAL. These roadways are not reported in the maintenance table described above for HPMS reporting. A reference is generated through a spatial join between the monitoring station point and the LRS Milepoint upon which it falls. The extent of highway this AADT represents has not been determined. This process captures the AADT for Local routes into the published table without requiring a comprehensive maintenance process. The AADT on Local routes may extend beyond the arc used to report it. The user must exercise their judgment in determining the extent of highway for an AADT in this case. There are over 16,000 records that are supplemental using this method, one record for each station captured. Vehicle Class data is provided for those segments where vehicle class data was collected. Truck volume data is collected at stations and the volumes are annualized. Annualized truck percentages for Single Unit (SU) and Multi Unit (MU) trucks are generated from this data. These truck percentages are applied to the 2021 AADT estimates to generate 2021 truck volume estimates. The truck percentage and volume estimates are provided in the shapefile. The VC coverage includes the National Highway System (NHS) and the NC Truck Network. VC data is not collected on routes not part of these systems and truck statistics are not provided on these segments. The referencing provided is based on the 2022 Quarter 1 publication of the NCDOT Linear Referencing System (LRS) maintained by the NCDIT GIS Unit. This is the official 2021 data set reported for HPMS routes, is the basis for the highway mileage reports, and is used to estimate vehicle miles of travel (VMT) for 2021. Differences in the Milepoints and references may be found when using other quarterly publications with this data set.
The Traffic Segment Event file contains Annual Average Daily Traffic (AADT) and Vehicle Class (VC) estimates. This resource represents the approved annual submission to the FHWA, Highway Performance Monitoring System (HPMS) reporting for calendar year 2021. We report AADT on all highways functionally classified (FC) above Local. A full coverage is provided for routes where AADT segmentation is based on network configuration, travel patterns, and land use. Where divided highways occur, the AADT total for both directions is referenced on the inventory direction. Data is provided for ramps also. The ramp data does not cover all ramp segments, but all major traffic flows at interchanges are reported. Some maintained traffic segments require multiple records due to route ID changes at the county boundary in the linear referencing system (LRS). Traffic statistics for these segments are the same on each side of the county boundary but are maintained in this format to preserve the different location referencing data. Over 31,000 reference records (labeled “MAINT” in the SOURCE field) are required to provide event data for all maintained AADT segments. Supplemental AADT are provided on the routes that are Functionally Classified LOCAL. These roadways are not reported in the maintenance table described above for HPMS reporting. A reference is generated through a spatial join between the monitoring station point and the LRS Milepoint upon which it falls. The extent of highway this AADT represents has not been determined. This process captures the AADT for Local routes into the published table without requiring a comprehensive maintenance process. The AADT on Local routes may extend beyond the arc used to report it. The user must exercise their judgment in determining the extent of highway for an AADT in this case. There are over 16,000 records that are supplemental using this method, one record for each station captured. Vehicle Class data is provided for those segments where vehicle class data was collected. Truck volume data is collected at stations and the volumes are annualized. Annualized truck percentages for Single Unit (SU) and Multi Unit (MU) trucks are generated from this data. These truck percentages are applied to the 2021 AADT estimates to generate 2021 truck volume estimates. The truck percentage and volume estimates are provided in the shapefile. The VC coverage includes the National Highway System (NHS) and the NC Truck Network. VC data is not collected on routes not part of these systems and truck statistics are not provided on these segments. The referencing provided is based on the 2022 Quarter 1 publication of the NCDOT Linear Referencing System (LRS) maintained by the NCDIT GIS Unit. This is the official 2021 data set reported for HPMS routes, is the basis for the highway mileage reports, and is used to estimate vehicle miles of travel (VMT) for 2021. Differences in the Milepoints and references may be found when using other quarterly publications with this data set.
The Traffic Segment Event file contains Annual Average Daily Traffic (AADT) and Vehicle Class (VC) estimates. This resource represents the approved annual submission to the FHWA, Highway Performance Monitoring System (HPMS) reporting for calendar year 2021. We report AADT on all highways functionally classified (FC) above Local. A full coverage is provided for routes where AADT segmentation is based on network configuration, travel patterns, and land use. Where divided highways occur, the AADT total for both directions is referenced on the inventory direction. Data is provided for ramps also. The ramp data does not cover all ramp segments, but all major traffic flows at interchanges are reported. Some maintained traffic segments require multiple records due to route ID changes at the county boundary in the linear referencing system (LRS). Traffic statistics for these segments are the same on each side of the county boundary but are maintained in this format to preserve the different location referencing data. Over 31,000 reference records (labeled “MAINT” in the SOURCE field) are required to provide event data for all maintained AADT segments. Supplemental AADT are provided on the routes that are Functionally Classified LOCAL. These roadways are not reported in the maintenance table described above for HPMS reporting. A reference is generated through a spatial join between the monitoring station point and the LRS Milepoint upon which it falls. The extent of highway this AADT represents has not been determined. This process captures the AADT for Local routes into the published table without requiring a comprehensive maintenance process. The AADT on Local routes may extend beyond the arc used to report it. The user must exercise their judgment in determining the extent of highway for an AADT in this case. There are over 16,000 records that are supplemental using this method, one record for each station captured. Vehicle Class data is provided for those segments where vehicle class data was collected. Truck volume data is collected at stations and the volumes are annualized. Annualized truck percentages for Single Unit (SU) and Multi Unit (MU) trucks are generated from this data. These truck percentages are applied to the 2021 AADT estimates to generate 2021 truck volume estimates. The truck percentage and volume estimates are provided in the shapefile. The VC coverage includes the National Highway System (NHS) and the NC Truck Network. VC data is not collected on routes not part of these systems and truck statistics are not provided on these segments. The referencing provided is based on the 2022 Quarter 1 publication of the NCDOT Linear Referencing System (LRS) maintained by the NCDIT GIS Unit. This is the official 2021 data set reported for HPMS routes, is the basis for the highway mileage reports, and is used to estimate vehicle miles of travel (VMT) for 2021. Differences in the Milepoints and references may be found when using other quarterly publications with this data set.