California Department of Transportation
 

QuickMap Frequently Asked Questions


Q: Where can I find a description of QuickMap?

A: Right here:

The California QuickMap web page presents several types of real-time traffic information layered on a Google Map. The information includes traffic speed, lane and road closures due to construction and maintenance activities, incident reports, Changeable Message Sign (CMS) content, camera snapshots, and active chain control requirements. Traffic speed is indicated by color-coded lines overlaying the roadway. The location of information content for the remaining layers is identified by markers (icon images) on the map. Clicking on a marker displays the information details in an info window pop-up.

The presentation of these different categories of information can be controlled with check boxes in the page's left column which enables the layers to be turned on or off. This also serves as a key to the marker images used for each type of information.

Image of traffic map check boxes from left column of QuickMap page.

Also see: Can you tell me more about the traffic information displayed on QuickMap?

Navigation

Left-click one of the Zoom to ... links in the page's left column to reach a pre-defined location and zoom level.

Image of the traffic map Zoom to ... links.

You can also navigate (pan and zoom) around the map using the standard methods of Google Maps:

  • Point at the map, left-click, and hold to drag the map to view adjacent sections.
  • Pan left, right, up and down with the arrow keys.
  • Pan wider with the Page Up, Page Down, Home and End keys.
  • Zoom in and out with the plus (+) and minus (-) keys.
  • Point at the map and double left-click to zoom in and center on the location pointed to.
  • Double right-click to zoom out (Ctrl+ double-click for Mac users).
  • Use the scroll wheel on your mouse to zoom in and out.
  • Use the Google Navigation Controls (on the right side of the map) by:
    • Clicking the appropriate arrow buttons to move the view north, south, east or west.
    • Click + to zoom in on the center of the map.
    • Click - to zoom out.
    • Drag the zoom slider up or down to zoom in or out incrementally.

QuickMap will save your location and zoom level between sessions. So the next time you visit the page from the same system you will be viewing the same location on the map.

If your browser is capable of location aware browsing, and configured to share your location, you can click the "Locate" button (upper left side of the map) to pan to your current location with a zoom level of 12.

Sharing a View

You can save the current location and zoom level by clicking on the "Share" button (upper left side of the map) and copying the displayed URL. The URL contains arguments for the location and zoom level, and can be pasted into a browser's address bar.

Road Map, Terrain, or Satellite

By default, the traffic layers are displayed on the standard Google road map. Clicking the "Satellite" button (upper right side of the map) replaces the road map with Google Earth satellite images. Clicking the "Map" button resets the display of the road map. And clicking the "Terrain" check box (made visible by pointing at the "Map" button while the road map is displayed) adds a physical map overlay based on terrain information.

Text Information

Much of the information presented by California QuickMap is also available from a text-based Highway Conditions web page. To view this information, enter the highway number in the input field half way down the left column and click on the nearby "check" button. Or, for a spoken version call: 1-800.427.7623. This information does not include the CHP incidents, but does include the lane closures, CHIN messages, and chain controls.

Regional 511 Links

In addition to the information presented by California QuickMap, there are links (bottom of left column) to regional 511 sites. These sites are provided by other organizations, in partnership with Caltrans, to supply comprehensive, commuter and multi-modal, traveler information within their regions.

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Q: Can you tell me more about the traffic information displayed on QuickMap?

A: Yes.

Traffic Speed Traffic Scale

The traffic speed data information is provided by using the Google Maps Traffic Layer. This enables California QuickMap to provide speed data beyond what is available using just Caltrans data. Google uses Caltrans data as well as other sources of data, like Automated Vehicle Location (AVL) from private companies, as well as cellular phone data. The colors represent speeds. Green means there is a normal speed of traffic. The more red the roads become, the slower the speed of traffic on the road.

For more information on the Google Traffic Layer see the following links:

Lane Closures Traffic Cone

Caltrans construction and maintenance activity that results in lane Traffic Cone and full-road Traffic Cone closures are shown by activating the Lane Closures layer.

Although the data files on the public servers include all active and planned lane closures, California QuickMap only shows the active lane closures. Planned Lane closures can be found using the Planned Lane Closures link on QuickMap or the department’s main web page.

The Lane Closure data files are updated every 5 minutes.

CHP / CHIN Incidents Warning Sign

Roadway incidents are presented using the publicly available California Highway Patrol incident feed combined with Caltrans highway information messages.

CHP incidents are indicated by yellow Warning Sign or red Warning Signmarkers to differentiate the severity of the incident. CHP incidents that involve closed lanes or result in a full closure are indicated by red markers. All other incidents are indicated by yellow markers.

Caltrans highway information markers are always red. If there is an incident with both CHP and Caltrans highway information, a single red marker is used. The resulting info window pop-up will display the Caltrans highway information message first, followed by the CHP indent information.

The roadway incident layer is updated every 1 minute.

Message Signs Message Sign

The Message Signs layer presents CMS markers only for signs with active messages. California QuickMap does not show markers for signs that are not currently displaying messages. The info window pop-up displays the message as it is shown on the changeable message road sign.

The Message Signs layer is updated every 1 minute.

Cameras Camera

The Cameras layer presents selected still images from cameras throughout the state. Still images were selected instead of providing full motion imagery to insure that the web page would be able to provide traveler information even during high demand periods. Since the camera images were never intended for use by the public when originally installed, Caltrans is currently working to upgrade and standardize the image quality and information provided. The period between image updates varies by location, depending on the communication technology currently used. The goal is to provide image updates every 20 minutes or less.

Chain Controls Tire Chains

The Chain Controls layer presents the active chain control requirements throughout the state. There are two markers used for chain controls, one is the diamond shape Warning SignRoad Closed Ahead sign and the other is the tire with chains Warning Signfor all other conditions. Restrictions are outlined in the info window pop-up. The chain control levels used in California are shown below.

Level Description listed in dialog box
ESC The California Highway Patrol is escorting all traffic due to weather conditions.
HT All traffic is being held at the chain control check point due to accidents or weather related conditions.
MAX Truck chain requirements are maximum for all trucks using Donner Summit.
MIN Truck chain requirements are minimum for all trucks using Donner Summit.
R-0 There are no chain restrictions at this time.
R-1 Chains, traction devices or snow tires are required on the drive axle of all vehicles except four wheel drive, all wheel drive vehicles.
R-1M Trucks & vehicles pulling trailers use R-1 restrictions.
R-2 Chains or traction devices are required on the drive axle of all vehicles except four wheel drive, all wheel drive vehicles with snow-treaded tires on all four wheels.
R-3 Chains or traction devices are required on all vehicles, no exceptions.
RC Currently the road is closed due to accidents or weather related conditions.
TH All truck trailer combinations are being held at the chain control camper due to accidents or weather related conditions.
TS All trucks must stop at the chain check point, Caltrans is currently screening for chains. Drivers must have maximum chains in their possession in order to proceed. Trucks without chains will be turned around. Permit loads are prohibited over the summit.
TTA All truck trailer combinations are being turned around at the chain control camper due to traction problems over Donner Summit.
TTS All single axle drive trucks pulling a trailer are being turned around at the chain control camper due to traction problems over Donner Summit.
TTSD All single axle drive trucks pulling a set of doubles are being turned around at the chain control camper due to traction problems over Donner Summit.
VM A traffic control is in effect to meter vehicles at the chain check point in order to reduce traffic congestion in the mountain areas.
W No Restrictions - Watch for snow on pavement.

The Chain Control layer is updated every 1 minute. Because of the current process used, this means that it will be between 1 and 5 minutes from the time the information is changed by Caltrans and the time it is reflected on the map.

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Q: Where does the information on the map come from?

A: Caltrans has many different systems that record information and then provide that information for public use.

All of the information presented by California QuickMap is pulled from files published on the Caltrans public servers. See the Commercial Wholesale Web Portal (CWWP).

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Q: How often is the information on the map refreshed?

A: The traffic information layers presented on Caltrans QuickMap are refreshed every 3 minutes.

During this time you will see a flicker of the layer content on the map as each layer is deleted and replaced. An open info window pop-up will disappear, since it was associated with the deleted layer content.

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Q: Why did the open info window pop-up disappear?

A: See How often is the information on the map refreshed?

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Q: How can I report an issue or ask a question?

A: Click the your feedback link that can be found on the Contact Us page.

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