Annual average daily traffic

Traditionally, it is the total volume of vehicle traffic of a highway or road for a year divided by 365 days.

Each year on June 15, every state's department of transportation (DOT) submits a Highway Performance Monitoring System (HPMS) report.

For federal funding, formulas are applied to include the VMT and other highway statistics.

This method includes sensors that are permanently embedded into a road and traffic data is measured for the entire 365 days.

For example, if the continuous count equipment is not operating for the full 365 days due to maintenance or repair.

[7] While providing the most accurate AADT, installing and maintaining continuous count stations method is costly.

These are typically pneumatic road tubes although other more expensive technology such as radar, laser, or sonar exist.

The FHWA Traffic Monitoring Guide[7] recommends performing a short count on a road segment at a minimum of every three years.