The publications and reports on this site that are labeled .pdf (portable document format) require Adobe Acrobat Reader to view them. The software can be downloaded free from Adobe's web site (one-time setup).
Welcome to the Traffic Data Branch
The Traffic Data Branch is responsible for the collection and dissemination of historical volumes (counts) and speed data. We also produce Mobility Performance Reports and we manage Weigh-In-Motion system data.
* For more specific reports, surveys, forecast documents, especially related to fuel consumption, Commercial Truck VMT, and VMT data per capita, for example, please use the link at the bottom of this page to connect to Caltrans Division of Research, Innovation, and System Information (DRISI).
TRAFFIC COUNTS, also called Traffic Volumes, are available in various formats, and are only for the State Highway System. We do not collect traffic counts on locally maintained streets.
State Highways are signed Interstate, California, and the US. Examples are pictured below:
Although we do not collect traffic count information on locally maintained streets, links to that information are provided here as a courtesy. Most local road data is available from the City or County Public Works Department or Community Development Office in the area where the street is located.
Caltrans traffic counts are summarized annually into three categories. Necessary software to download .pdf files can be obtained for free by clicking on the desired link in the grey column on the right side of this page:
For the most current downloadable format in pdf, click on the following: 2012 Traffic Volumes Book
For those with accessibility needs, the 2011 Truck report is also available in .doc format: 2011Truckdoc.
3. Ramp Volumes on California State Freeways. For downloadable pdf files (organized by Caltrans Districts 1 through 12), click on the following link: 2012.
The 2012 Peak Hour Volume Data Report (.pdf) consists of hourly volume relationships and traffic monitoring sites on the State highway system. Morning (AM) and afternoon/evening (PM) peak periods are expressed as a percentage of Annual Average Daily Traffic (AADT).
Peak Hour reports for previous years are also available: 2011, 2010, 2009, 2008, 2007
For questions regarding AADT reports, Ramp Volumes, or the Peak Hour Volume Data Reports above, please contact: Cindy.Pribyl@dot.ca.gov, or (916) 654-4578
2010Truck, 2009Truck, 2008Truck, 2007Truck,
2006Truck, 2005Truck, 2004Truck, 2003Truck, 2002Truck, 2001Truck, 2000Truck (revised),1998Truck, 1997Truck, 1996Truck, 1995Truck, 1994Truck, 1993Truck, 1992Truck
Some of these publications are also available for a nominal fee in hard copy format from Caltrans Publications office at (916) 263-0822, or (916) 263-0865. To order on-line, or by mail or fax, go to http://caltrans-opac.ca.gov/publicat.htm.
The Traffic Data Branch produces a monthly Vehicle Miles of Travel (VMT) report (often called the "Trend" report). This report estimates the number of vehicle miles that motorists traveled on California State Highways using a sampling of up to 20 traffic monitoring sites. Various roadway types are used to calculate VMT.
For information regarding the monthly trend reports or historical speed data, please contact: Viki.Duncan@dot.ca.gov
Additional Vehicle Miles of Travel reports available on this site:
Historical Monthly VMT(.pdf) - Lists monthly/annual statewide Vehicle Miles Traveled (VMT) on State Highways for the past 40 years. 1972-2012.
The Traffic Data Branch also compiles Mobility Performance Reports (MPRs). Caltrans began preparing the annual Mobility Performance Report (MPR) in 2009 as a new type of congestion report using data collected from every day of the year. This report replaces the Highway Congestion Monitoring Program (HICOMP) Report and represents the completion of a transition to an improved way of measuring congestion.
For information regarding MPRs, please contact: Drucilla.Dunton@dot.ca.gov or visit her site at
Data Weigh-in-Motion (WIM) systems provide 24-hour traffic information at key locations on California highways.
Data: The information collected includes:
Axle weights and gross weight
For information regarding Weigh-In-Motion (WIM) stations, please contact: Vicki.Dickey@dot.ca.gov
For more technical information regarding the WIM system or a map of California's WIM locations visit:
FOR ADDITIONAL INFORMATION NOT FOUND HERE,
PLEASE CONTACT THE TRAFFIC DATA BRANCH MANAGER:
* For travel reports, surveys, and forecast documents, especially related to fuel consumption, Commercial Truck VMT, and VMT data per capita,
please contact another area of Caltrans: