Average Annual Daily Traffic (AADT)
The annualized average 24-hour volume of vehicles at a given point or section of highway. It is normally calculated by determining the volume of vehicles during a given period, and dividing that number by the number of days in that period. Also known as a "Traffic Count".
How we obtain Traffic Counts:
Automatic Traffic Recorder (ATRs):
The ATRs collect data 24 hours a day, 365 days annually, for each lane. The equipment records traffic volumes, speed and classification of vehicles. MPD uses this data to develop seasonal factors, daily factors, axle factors and estimate vehicle miles of travel (VMT). These factors are applied to all coverage counts.
Coverage counts are needed to ensure that adequate geographic coverage exists for all roads under the jurisdiction of the State highway authority. In simple terms, "coverage counts" are data collection efforts that are undertaken to ensure that "at least some" data exist for all roads maintained by the agency.
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AADT Reports (Traffic Counts)
K D & T Factors (prior 2010)
AADT Data Dictionary - Defines the column headings and code values used in these files.
Traffic Projection Data Dictionary - Defines the column headings and code values used in these files.
K D & T Factor Data Dictionary - Defines the measurements and column headings used in these files.
Local Government Agency Transportation Links - Alphabetical listing of links or telephone numbers to local government agencies in Arizona. Aslo provides links to COG's, MPO's and Other Agencies.
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