Traffic Census Program

Traffic Counts (a.k.a. Traffic Volumes) are for the State Highway System only (in various formats).

Highways are signed as Interstate, California State Route, or United States Route. See examples below:

interstate route shield   state route shield   US route shield

Traffic count information for city and county streets may be found at the city Traffic Engineering or Public Works Department, or the Community Development Office in the area where the street is located.

Explanation of Traffic Counts (Back & Ahead Leg Diagrams) (PDF)

Caltrans Traffic Counts are summarized annually into four categories:

Traffic Volumes: Annual Average Daily Traffic (AADT)
For ALL vehicles on California State Highways
All files are .XLSX
2021 AADT 2022 AADT N/A N/A N/A
2016 AADT 2017 AADT 2018 AADT 2019 AADT 2020 AADT
N/A N/A 2013 AADT 2014 AADT 2015 AADT

by Webpage:  2017

Truck Traffic: Annual Average Daily Truck Traffic
For truck traffic on California State Highways
All files are .XLSX
2021 AADT Truck 2022 AADT Truck N/A N/A N/A
2016 AADT Truck 2017 AADT Truck 2018 AADT Truck 2019 AADT Truck 2020 AADT Truck
N/A N/A 2013 AADT Truck 2014 AADT Truck 2015 AADT Truck
Peak Hour Volume Data
Hourly volume relationships and traffic monitoring sites on the State Highway System.
Morning (AM) and evening (PM) peak periods are expressed as a percentage of AADT
All files are .XLSX
2021 2022 N/A N/A N/A
2016 2017 2018 2019 2020
N/A N/A N/A 2014 2015

For questions regarding AADT reports, Ramp Volumes, or the Peak Hour Volume Data Reports above, please contact Hasib Mohabbat.

For AADT GIS data, visit the Caltrans GIS Data webpage.

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