Caltrans GIS Data

Truck AADT

Truck Traffic Volumes (Truck AADT)

Point GIS datasets represent Truck Traffic Volumes (Truck Annual Average Daily Traffic (AADT)) for selected locations on the California State Highway System.

Data Created: August 20, 2014
Last Modified: March 4, 2018


Annual average daily truck traffic is the total truck traffic volume divided by 365 days. Truck counting is done throughout the state in a program of continuous truck count sampling. The sampling includes a partial day, 24-hour, 7-day and continuous vehicle classification counts. The partial day and 24-hour counts are usually made on high volume, urban highways. The 7-day counts are made on low volume, rural highways. The counts are usually taken only once in the year. About one-sixth of the locations are counted annually. The resulting counts are adjusted to an estimate of annual average daily truck traffic by compensating for seasonal influence, weekly variation, and other variables that may be present. Annual average daily truck traffic is necessary for presenting a statewide picture of truck flow, evaluating truck trends, planning and designing highways and for other purposes.

Truck traffic is classified by number of axles. The two-axle class includes 11/2-ton trucks with dual rear tires and excludes pickups and vans with only four tires. Total vehicle AADT for the same year is taken from the Traffic Volumes on California State Highways booklet also published by the California Department of Transportation.


The maps and data are made available to the public solely for informational purposes. Information provided in the Caltrans GIS Data Library is accurate to the best of our knowledge and is subject to change on a regular basis, without notice. While the GIS Data Management Branch makes every effort to provide useful and accurate information, we do not warrant the information to be authoritative, complete, factual, or timely. Information is provided on an "as is" and an "as available" basis. The Department of Transportation is not liable to any party for any cost or damages, including any direct, indirect, special, incidental, or consequential damages, arising out of or in connection with the access or use of, or the inability to access or use, the Site or any of the Materials or Services described herein.


Tags: Truck Traffic Volumes, Annual Average Daily Traffic, Truck AADT, Truck Traffic Counts, California State Highway
Credits: California Department of Transportation

2010 Truck Traffic Volumes:, size 0.389 MB
2011 Truck Traffic Volumes:, size 0.379 MB
2012 Truck Traffic Volumes:, size 0.305 MB
2013 Truck Traffic Volumes:, size 0.235 MB
2014 Truck Traffic Volumes:, size 0.242 MB
2015 Truck Traffic Volumes:, size 0.452 MB
2016 Truck Traffic Volumes:, size 0.554 MB

Extent: California statewide
References: Traffic Data Branch: