California Department of Transportation

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Portal Manager:
Narayan Selwal
Senior Transportation Engineer
Traveler Information, and Park & Ride Program
Caltrans HQ Traffic Ops
Sacramento, CA 95814
Office :(916) 653-4670

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Commercial Wholesale Web Portal

CWWP Information

Traffic Detection | Closed Circuit Television | Changeable Message Sign | Lane Closures | Weather | Chain Control

More About CWWP

The Travel Information Commercial/Media Wholesale Web Portal (CWWP) is designed to help commercial and media Information Service Providers (ISPs) request and receive traveler information generated by the California Department of Transportation (Department). The Department recognizes ISPs are experts in media and customer needs, and are better able to widely distribute travel information to other businesses and to the public.

The Department hopes ISPs will use the information we make available through the CWWP to support the Department's mission of "improving mobility across California" and our goals for improving safety, trip reliability, efficiency, and multi-modal choice. The Department wants to maximize the widespread distribution of travel information, so that travelers will have easy access to readily available information to make informed choices on their travel times, routes and modes.

The CWWP standardizes and ensures all ISPs have equitable access and standardizes ISP registration.

Metadata (file configuration)

File configurations often differ between data sets and districts creating the data. This is due to different software/versions, procedures, and telecommunications infrastructure in different parts of California. Generally each data set will come with explanation. The section below describes some of the major commonalties and differences in major data sets.

Traffic Detection (ATMS and PeMS)

Traffic detection is generally used to observe speed and volume along freeway segments. Currently seven districts (03, 04, 06, 07, 08, 11, and 12) collect dynamic speed/congestion data, covering 70% (Currently 3,500 detection sensors exist; approximately 5,000 are needed for full coverage of mainline and ramps.) of the 4,000 miles of freeways, and almost none of 12,000 miles of conventional highways. The field data are collected and reported electronically every 20 or 30 seconds. Detection station locations are identified by county/route/postmile and will require ISPs to convert the location reference to their GIS location referencing.

Transportation Management Center (TMC) operators use Advanced Transportation Management Software (ATMS) to detect and mange traffic backup from incidents, expedite incident clearance, and manage disasters and special event traffic situations. The ATMS data also feeds the Department's Performance Measurement System (PeMS) used by others within the Department and externally, including researchers and ISPs.

Advanced Transportation Management Software (ATMS)

Many districts post dynamic ATMS feeds for ISPs to download. Eventually all districts will use the standard 'California-wide ATMS' or Advanced Transportation Management Software. Currently District 04 has a unique system, District 11 utilizes a mix of ATMS with its legacy "freeway management system" software, and the others use various "builds" and features of the departmental standard ATMS v2. Configurations often differ between district ATMS feeds linked to the CWWP.

Performance Measurement System (PeMS)

PeMS is the Department's main software for deriving freeway system performance measures. It presents the ATMS traffic detection data in a common statewide format (30-second volume & occupancy by lane), and has archival and current data available. PeMS provides both "raw" and "cleansed" versions of the data. The "cleansed" includes 5-minute moving average to correct for traffic fluctuations.
Go to the PeMS site.

Closed Circuit Television (CCTV)

The Department has about 1,300 closed circuit television cameras (CCTV) that provide TMC operators visual analysis of freeways, highways, and other transportation infrastructure. Several districts make at least some CCTV images available to commercial/media ISPs including media traffic reporters and to the general public via the Department's and individual districts' Internet pages. The Department's ability to share CCTV is tempered by security and privacy issues as well as limitations imposed by older technologies and telecommunications.

Many of the older CCTV are not Internet compliant, and telecommunications infrastructure and business requirements vary from district to district. In an urban district newer CCTV may be connected via fiber optics, use Internet formats, and have streaming and still images which are updated every minute or two. In rural areas the images may only be updated once an hour, as access is via telephone modem. Districts vary in format, size, dimensions, and update frequency.

The Department official homepage links to "Caltrans Live Traffic Cameras" ( where it provides central links to streaming cameras from an increasing number of districts. These videos are either Real Media or Windows Media format. Both players can be downloaded free of cost at their company's web sites. Download links are also available on the Department's web site:

Districts' Internet pages may have links to additional CCTV cameras that show traffic and weather conditions. For example, District 2 (Redding) stores JPEG images that are updated hourly and shows images for the last 8 hours. Districts 3 (Sacramento) and 8 (San Bernardino) are at the forefront in distributing CCTV. Their TMCs provide both high-bandwidth streaming and low-bandwidth still images for nearly all of their CCTV. Other districts are adopting the CCTV processing technologies used by Districts 3 and 8.

Television Broadcasts from TMC

While not actually a CCTV distribution method, several commercial media ISPs broadcast television traffic reports from TMCs. When a local television station sets up its own cameras, and a CHP officer reports live broadcast from TMC, background images often show CCTV images. District 03, 04, 06, 10, 07, and 11 have this type of arrangement with their local TV stations.

Changeable Message Sign (CMS) Messages

Some districts with ATMS software are able to provide feeds of messages they post on Changeable Message Signs (CMS). Typically these messages are incident/delay related, warning drivers to take specific defensive actions such as accident ahead/merge left/lane closed. Other messages may be advisory; e.g., dense fog/slow vehicles ahead, request motorist assistance as for child abduction alerts, or current travel times between freeway segments.

These messages may be embedded in the ATMS, or be separate feeds, depending on the district.

Lane Closures (Lane Closure System - LCS)

The Department has standardized its road and lane closure reporting into a statewide Lane Closure System (LCS). Every ten minutes LCS reports all approved closures planned for the next 7 days, plus all current lane, ramp, and road closures due to maintenance, construction, special events, etc. The report format is delineated text, downloadable via http.

Weather (Roadway Weather Information Stations - RWIS)

The Department has 150 weather, visibility, and environmental sensing units located on the highway system, mostly in rural areas or areas with recurrent weather conditions. Locations typically include mountain passes/key elevations, Central Valley fog areas; and desert high wind areas. Districts 2, 3, 6, 8 and 10 have nearly all of the RWIS locations. Districts 2 and 3 share dynamic RWIS information via the Internet, and an effort is underway to standardize and centralize the information databases by Fall 2005. As with ATMS and PeMS, locations are by county/route/postmile and ISPs will need to convert to their location referencing system. Portable RWIS units are typically placed at a location seasonally, such as during the October-March fog season in the Central Valley, or near multi-month construction zones.

Chain Control

The Chain Control data represents each Caltrans District and their use of chain controls based on events that warrant the need for vehicles to use chains on state highways. The Chain Control data gives the information necessary for users to identify the location and type of Chain Control and is only in the CSV format.