OOH glossary · Measurement
Traffic count (AADT)
A traffic count tallies vehicles passing a road point; AADT is the daily average across a year.
FHWA defines AADT, annual average daily traffic, as a road’s yearly vehicle total divided by 365. It stands for a typical day.
State DOTs count traffic on major roads and publish the results. Billboard companies often list AADT on photo sheets.
AADT counts vehicles, not people, and not people who notice the ad. Geopath uses traffic counts to build circulation, then estimates impressions.
Formula
AADT = total vehicles in a year ÷ 365
Example
The state counts 7.8 million vehicles a year past B-114. AADT = 7,811,000 ÷ 365 = 21,400 vehicles a day.
In Gabie
Scout ranks open faces by daily traffic and quotes the DOT count on record. It never calls that count people or impressions.