Long Range Planning – AADT
(Annual Average Daily Traffic)
An AADT traffic volume is used throughout the project planning process to provide projected volumes of traffic. It is based on a 24 hour, two directional count at a given location. This raw traffic volume is then mathematically adjusted for vehicle type, determined by an axle correction factor. Then this volume is statistically corrected by a seasonal variation factor that considers time of the year and day of the week.