Annual average daily traffic
（重定向自Average Daily Traffic）
![Highway 401 in Ontario, Canada, has an AADT of over 400,000 in some sections of Toronto.[1]](/Images/godic/202412/22/Highway_401_east_of_Highway_4001851.jpg")
![A traffic counter on BIA Road J-9 in the United States](/Images/godic/202412/22/Traffic_Counter_on_BIA_Road_J-91851.jpg")
Annual average daily traffic, abbreviated AADT, is a measure used primarily in transportation planning and transportation engineering. Traditionally, it is the total volume of vehicle traffic of a highway or road for a year divided by 365 days. AADT is a useful and simple measurement of how busy the road is. Newer advances from traffic data providers are now providing AADT by side of the road, by day of week and by time of day.