Here is a list of frequently asked questions about the 511 traffic site. The answers will tell you what content you can find on the site, how to use the site?s features, and how to troubleshoot technical issues. If you have a question that?s not answered on this page, please contact us.

• What does the 511 Traffic Site have to offer?
• Where can I find information on HOV lanes in the Bay Area?
• What browser versions does the 511 Traffic site support?

• How do I open and close the Traffic and Driving Times Map window?
• What are the different parts of the Traffic and Driving Times Map Window, and what do they do?
• How do I use the Map Tools?
• What kinds of information does the Traffic and Driving Times Map show?
• How are the different congestion levels shown in the Traffic Congestion layer translated into speeds?
• Why does the cursor change shapes (dependent on the traffic tool I select) on one computer and not on another one?

• What does it mean if there is a dash in place of a driving time under the Popular Driving Times section of the home page?
• How do I use the Driving Times feature?
• How does the Driving Times feature work?
• When and on what roads will Driving Times be available?
• How do I use the 511 Driving Times^SM (text version)?
• On the 511 Driving Times^SM (text version) page, what do the "traffic info summary", "incidents", "events", "construction", and "cameras" links do?
• How are FasTrak™ Customers Participating in Driving Times?
• Will my privacy be protected?
• Can I elect not to participate in this 511/ FasTrak™ data collection program and still be a FasTrak™ customer?
• Who is responsible for Driving Times?
• Where do the driving times estimates on changeable message signs come from?
• Where do I find out more about driving times on the changeable message signs?

• What are Traffic Messages?
• How can I view the site's Traffic Messages?

• What is Predict-a-Trip^SM?
• What does "typical" mean?
• How does Predict-a-Trip^SM work?
• How do I use the Predict-a-Trip^SM feature?
• Can I use Predict-a-Trip^SM from the Driving Times Map Feature?
• Why are Tuesday, Wednesday, and Thursday not separate days of the week?
• What holidays are included in the Holidays category?
• How is Thanksgiving defined for Predict-a-Trip^SM?
• How accurate is Predict-a-Trip^SM?

• What are the minimum computer specifications required to watch Caltrans streaming video?
• Do I have to use Windows Media Player to view the Caltrans streaming video?
• Do I need a specific version of Windows Media Player?
• My popup blocker won't let me watch the Caltrans videos. How can I fix that?
• Why do video clips sometimes stop or pause?
• I can open Windows Media Player, but cannot see any video.
• What if Windows Media Player is not my default player?

• When I use the Traffic and Driving Times Map, why do my browser buttons disappear?
• How come when I click on an incident, event, construction, or color-coded roadway on the map, I do not see any information in the Information Detail Box?
• I made a mistake when I picked my starting point circle. What do I do now?
• What if I want more information or I want to talk to someone at MTC?
• What are cookies and why are session cookies used on the 511 Traffic Web site?
• Sometimes the traffic data seems to be different in the different browser windows.
• Why can I use everything on the web site except 511 Driving Times^SM?
• Why does the traffic map show up as all black in my Mozilla browser window?
• I keep getting "Invalid width of IMAGESIZE" errors when I use Safari to view the detailed traffic map

What does the 511 Traffic Site have to offer?
The 511 Traffic Site contains real-time traffic information and other tools to help you plan your trips and commute in the Bay Area. Its main features are:

• An interactive Traffic and Driving Times Map, which can give you driving times, traffic incidents, congestion levels, construction, and special events affecting traffic (Try clicking on the color-coded roadways to obtain speed information). Streaming video of local traffic cameras is also available for viewing.
  
• 511 Driving Times^SM (text version), a text-based Driving Times feature, for those who prefer to calculate driving times through a table as opposed to the Traffic and Driving Times Map;
  
• Traffic Information (text version), a tabular way to view the same data located on the Traffic and Driving Times Map: incidents, construction, special event information, and links to traffic camera video streams. The table is sortable by all columns. If you sort by route, all traffic events affecting your roadway can be viewed together.
  
• 511 Driving Times^SM Coverage, a map illustrating where 511 can provide driving times
  
• Up to the minute Traffic Messages from around the Bay Area, giving needed information about conditions and events affecting traffic and identifying high and low message priorities
  
• Links to other Bay Area organizations who provide Local Traffic Information and are implementing Traffic Management Systems to improve local traffic
  
• Information on Fastrak™, the Bay Area's electronic bridge toll collection program, including details on how to sign up for the service to receive a FasTrak™ transponder.
  
• Links to Traffic Partners
  
• This FAQ section
  
• Other helpful information about 511 and MTC, including our contact information, accessibility and privacy policies, and how to make suggestions and provide feedback
  

Where can I find information on HOV lanes in the Bay Area?
Information on the HOV lanes is available and can be found on the Carpool Lanes page located in the 511 Rideshare Website.

What browser versions does the 511 Traffic site support?
The 511 Traffic web site is designed to work with Internet Explorer 6 and 7, Firefox 2.x and above, and Safari. Many features of the web site are accessible on older browser versions, but to enjoy all of the traffic site's features you may need to download the latest version of your favorite browser. To download the latest version of Internet Explorer, click here. To download the latest version of Firefox, click here. To download the latest version of Safari, click here.

How do I open and close the Traffic and Driving Times Map window?
When you click on the Traffic and Driving Times Map graphic at the center of the Traffic Home Page or click the "Traffic and Driving Times Map" link on the navigation bar, the map will open in a pop-up window. This window may only occupy part of your screen. To increase the size of the map, click the "Maximize" button (for PCs), or the second-to-right button on the window (for Mac) and the Map window will expand to the whole screen. This browser window will not contain the standard set of browser tools. Refer to the first question under Troubleshooting for more information.

Once the map window appears, the map itself will take a moment to load. If during that time (or at any time) you decide you don't want to see the map anymore, you can simply close the window to return to the Traffic Home Page.

What are the different parts of the Traffic and Driving Times Map Window, and what do they do?
The Traffic and Driving Times Map contains the following parts:

• The Navigation Bar on the top left-hand side, operates exactly like the Navigation Bar on the rest of the Traffic Site.
  
• Map Tools are located on the left-hand side beneath the navigation bar. These tools allow you to view different areas of the map and get different information. To learn more about Map Tools, see the next question, "How do I use the Map Tools?".
  
• The Map Refresh Interval Control is located just below the Map Tools. This control allows you to choose how long the map will wait to automatically reload with updated information. A shorter delay means you will get new information more quickly, but this update may also interrupt you. A longer delay (or no delay) means you do not receive fresh information as often, but it can make it easier to use the map without interruptions.
  
• The actual Traffic and Driving Times Map is located in the middle of the window.
  
• The Overview Map is located in a small box on the upper left-hand side of the Traffic and Driving Times Map. This Overview Map shows the entire Bay Area with a smaller red rectangle that shows the area currently being viewed on the Traffic and Driving Times Map. By clicking on the small black triangle in the top-right corner of the Overview Map, you can hide the Overview Map to only show the title bar. By clicking the triangle again, you can restore the Overview Map to its normal size.
  
• The map legend, labeled Traffic Congestion, is located in the lower-left-hand side of the Traffic and Driving Times Map. The legend explains the different color codes used on the Traffic and Driving Times Map. By clicking on the small black triangle in the top-right corner of the Traffic Congestion box, you can conceal the map to show just the title bar. By clicking the triangle again, you can restore the legend to its normal size.
  
• The color scheme option control is an accessibility feature and is located in the Traffic Congestion legend box. This allows you to choose, if needed, a better color scheme for viewing the map.
  
• The Information Detail box, located on the upper, right-hand side of the window, contains tips on using the Map Tools (see next question below). Requested information regarding traffic conditions also appears in this area. Click here for more details on what kinds of information are shown.
  
• The Show/Hide Box appears in the lower-right-hand corner of the window. This box lists the different types of information, which can be seen on the map and allows you to choose which information you want to view. All the boxes are automatically checked when you first start, meaning all the information can be seen. If you click any of the check boxes, the check mark is deleted and that feature is removed from the map seconds later. Click the box again, and the feature reappears.
  

How do I use the Map Tools?
The Map Tools are the buttons that appear on the left-hand side of the map window. These tools help you navigate around the map and get the information you want. They include:

• Information Tool: Click this button to highlight it. Now, click on any part of the map that contains traffic information, including the color-coded roadways. The relevant information will appear in the Information Detail Box in the upper, right-hand column. For more about the types of information you can view, see next question below.
  
• Driving Times: Click this button to highlight it. For more on using this tool, click here.
  
• Zoom In: Clicking this button does not automatically zoom in on the map, but rather allows you to choose where you want to zoom in. When you click the Zoom In tool, the button highlights. Move the cursor to the area you want to zoom into and click and hold down the mouse button. While holding down the button, drag the cursor until the rectangle being drawn represents the area you want to see. Release the mouse button, and the map zooms into the area you selected. You can also just click on the map with the Zoom In tool selected and the map automatically zooms in one level.
  
• Zoom Out: Clicking this button highlights the tool. Click on the map to zoom out one level with the map now being centered where you clicked. Continue clicking if you need to zoom out more. If the map is already zoomed out fully, this tool will have no effect.
  
• Pan: Click this button to highlight it. Click on the map and hold down the mouse button. You can now drag the map in any direction. Release the mouse button to stop the panning.
  
• Re-center Map: Click this button to highlight it. Click on the map, and it will re-center on the position where you clicked, Please note that the zoom level will stay the same.
  
• Zoom to Entire Map: Click this button to zoom out and show the full Bay Area map. Note that whatever tool was previously selected remains selected.
  
• Refresh Map: Click this button to update the map with the most current information. Whatever tool was previously selected remains selected.
  

What kinds of information does the Traffic and Driving Times Map show?
The Traffic and Driving Times Map shows five main kinds of information, all of which reflect real-time conditions:

• Traffic Congestion: The map shows the highways in the Bay Area and color-codes each according to how congested it is at the current time.
  
• Speeds: Select the Information Tool (see question above) and click on any portion of a color-coded highway to view speeds at that location. All information will appear in the Information Detail Box located in the upper, right-hand column.
  
• Incidents: "Incidents" refer to traffic accidents, stalled vehicles, debris, etc. that affect traffic conditions. The incidents are located on the map using the incident icon . Click on an incident icon after selecting the "Information" tool to see a description and relevant details all found in the Information Detail Box.
  
• Events: "Events" refer to sporting events, concerts, parades, and any other public event that can affect traffic. The icon shows the locations of all events. As with incidents, you can click on an event icon with the "Information" tool selected to show event details in the Information Detail Box.
  
• Construction: The icon shows locations where road construction is affecting traffic. Again, clicking on a construction icon with the "Information" tool selected will show relevant information in the Information Detail Box.
  
• Cameras: The icon shows locations where local traffic cameras are deployed. Clicking on the camera icon with the "Information" tool selected will provide a link in the Information Detail Box that can be used to view the camera's live video stream.
  

Remember that the "Information" tool must be selected if you want to view specific traffic information in the Information Detail Box.

How are the different congestion levels shown in the Traffic Congestion layer translated into speeds?
Traffic conditions are delineated by color bands along the roadways. Each color denotes a different level of congestion. The following table shows the defined congestion levels displayed in the Traffic Congestion legend. Note that speed ranges are calculated as a percentage of the speed limit for each roadway segment. The "No Data" congestion level is used to indicate roadways for which there is no information currently available that would allow a congestion level to be determined.

Why does the cursor change shapes (dependent on the traffic tool I select) on one computer and not on another one?
To remind the user what map tool is selected the cursor is designed to change shapes based on the selected tool. For example, the cursor will become a magnifying glass with a "+" sign when the Zoom In tool is selected; a magnifying glass with a "-" sign for Zoom Out; a "?" when the Information tool is selected; etc. However, because many different browsers allow users to either knowingly or unknowingly override these cursors, you might be able to see the different-shaped cursors on one computer but not on another. Nevertheless, be assured that all cursors have the same impact on the Web site and no functionality is lost if you do not see the different-shaped cursors.

What does it mean if there is a dash in place of a driving time under the Popular Driving Times section of the home page?
The dash means that for some reason the 511 system is currently not able to provide a driving time. The reasons are either that a driving times sensor is not functional or that traffic is moving at less than 2 mph somewhere along the corridor, thus making our prediction unreliable.

How do I use the Driving Times feature?
The Driving Times feature calculates the current driving time between two points in the Bay Area. To use this feature, first click on the "Driving Times" tool in Map Tools, which looks like this:

A set of light blue circles will appear on the Traffic and Driving Times Map. These circles represent starting points and future starting points. Therefore, to receive a driving time please only choose starting and ending points along the corridors where we have Driving Times data. Refer to 511 Driving Times^SM Coverage for more information on current road coverage for Driving Times.

To begin, click on the circle closest to the point from which your trip will start ensuring that the point is along those corridors where we have data. Your selected circle remains light blue and all others turn magenta. These magenta circles represent destination points and future destination points. Click on the magenta circle closest to your destination again making sure that the point is along the corridors where we have data. The Information Detail Box, located in the upper right-hand column of the page, will show the heading, "Driving Times," and will display a selection of routes, along with the current travel time for each route, given current conditions. Click on the "More details..." link below the routes to display more detailed information in a pop-up window. If only one route is given, it means the system can only calculate one available route given your choices. When you are finished finding the driving time for your route, you can always click the driving time icon again to calculate the travel time for another route.

Please note that 511 Driving Times^SM is designed to allow you to use the other map tools while still having the Driving Times feature active. Therefore, if you want to exit Driving Times at any time, please click on the link, "Cancel driving time calculation." found in the upper right-hand box of the site.

There may be occurrences when the driving times are calculated using historical data instead of real-time information. This will happen if there is a system problem and real-time data for a particular part of your selected route is not available. A message is displayed indicating when historical information has been used to calculate driving times along the route.

The selected route may also contain segments for which no data is available for calculating driving times. In this case, no driving times will be shown for the selected route. Again, to see where we do have Driving Times coverage, check out 511 Driving Times^SM Coverage.

How does the Driving Times feature work?
This new feature is made possible by combining the existing Caltrans data collection system with a new system that MTC is developing with the help of FasTrak™ customers. The Caltrans system embeds pairs of metal loops into the pavement of certain freeways. These loops are able to determine when a vehicle passes over them. By measuring the time it takes for a vehicle to go between two loops, the system can determine the speed of traffic at that point. Travel times can then be estimated from the speed data.

The new system that MTC is developing uses small antennas over freeways to read FasTrak™ toll tags (the small devices typically installed on car windshields). When a car with a FasTrak™ toll tag drives by an antenna, the system detects the presence of the toll tag. Unlike the antennas at the toll plazas, the antennas installed for 511 will not cause the toll tags to beep, so there will be no annoying noises for drivers. The 511 system immediately scrambles the toll tag's identification number in order to protect personal privacy. When the car passes the next 511 antenna, the system again detects the toll tag, and again scrambles its number, using the same process. By averaging the travel times of all vehicles over a certain period, the system can calculate the average travel time and speed.

The 511 system combines the information from these two data sources to calculate the time it takes to travel between two points.

When and on what roads will Driving Times be available?
Driving Times are currently available on many freeway segments and will be available for all of the Bay Area's major freeways by early 2005 as we continue to build our network of traffic sensors. Currently, Driving Times are available on the I-80 corridor from San Francisco to Hwy 12 in Suisun City (including the San Francisco/Oakland Bay Bridge, the MacArthur Maze, and the Carquinez Bridge), I-680 from Hwy 4 in Pacheco to I-580 in Dublin, I-880 from I-80 in Oakland to Dixon Landing Road in Fremont, US 101 from Hwy 12 in Santa Rosa to the Golden Gate Bridge Toll Plaza, US 101 from San Francisco to Hwy 92 in San Mateo, I-580 from US 101 in San Rafael to I-80, I-280 in San Francisco and on the Golden Gate, Richmond-San Rafael, San Mateo-Hayward, and Dumbarton bridges. The rest of the region will be added in 2005.

Refer to 511 Driving Times^SM Coverage for more information on current road coverage for Driving Times.

How do I use the 511 Driving Times^SM (text version)?
The 511 Driving Times^SM (text version) feature allows you to calculate the current driving time for your route without using the map.

Getting current driving times using the 511 Driving Times^SM (text version) involves a two-step process. When you arrive at this page, you will see a heading saying "Step 1: Please enter your origin." Beneath this heading are three input boxes, labeled "City", "Route", and "Intersection." In the "City" box, select the city where your trip will begin. You can type the first letter of the city to jump to that part of the list. For "Route", select the highway you will start on (note that only routes passing through the selected city are shown). Finally, for "Intersection", choose the closest intersection where you will enter the highway (the "Intersections" box will now contain only intersections on that highway in that city). When you have filled in all three input boxes, press the "Submit Query" button.

You will be taken to a screen with the heading: "Step 2: Please enter your destination." Enter the city, route, and intersection where you will exit the highway, and press the "Submit Query" button.

A new page will appear containing a number of tables where each table represents a trip option between your origin and destination points. The tables show driving times and speed.

The heading for each table reveals the driving time for the trip option, while the columns in each table show details for different parts of the route. These details include:

• Road: each route is divided into segments, one for each highway taken on the route. The segments (highways) are listed in this column in the order in which they occur along the route.
  
• Min Speed: the lowest current speed along that highway (This will indicate if there are any bottlenecks or slowdowns on this highway).
  
• Max Speed: the highest current speed along that highway (this will indicate areas of no traffic congestion along the highway).
  
• Avg Speed: the current average speed along that highway.
  

On the 511 Driving Times^SM (text version) page, what do the "traffic info summary", "incidents", "events", "construction", and "cameras" links do?
If you click on the "traffic info summary" link, you will be taken to a page that will list all current traffic information (incidents, events, and construction). This information will be shown in a table with columns for the information type, the route (if applicable), the start time, estimated duration, and a description. If more details are available then a link will be provided that can be selected to display more detailed information. Each of the columns can be sorted by clicking on the column heading text. An arrow will appear next to the column heading text showing whether the sorting is in ascending or descending order.

If you click on the "incidents" link, you will be taken to a page that lists all current traffic incidents (i.e., collisions, stalled vehicles, debris, etc.) in the Bay Area. This page will list the incidents in a table, which will show the highway (location), start time, estimated duration, and a brief description of each incident. The incidents in the table are sorted according to the time they occurred but can be sorted by clicking on any of the column headings. For more information on a specific incident, just click on the "More info..." link included with the incident description.

The "events" and "construction" links operate the same way for both planned events that affect traffic (e.g., sporting events or concerts) and highway construction sites.

If you click on the "cameras" link, you will be taken to a page that lists the links to live video streams from local traffic cameras. Selecting a link on this page will display the current live video stream of the selected camera (this features requires Microsoft Windows Media Player).

How are FasTrak™ Customers Participating in Driving Times?
FasTrak™ customers participate simply by leaving their toll tag on the windshield for the antennas to read it. By doing so, they are helping provide important information on traffic conditions to Bay Area drivers through 511 and 511.org. The more tags providing data for Driving Time Calculations, the more accurate the information will be.

Will my privacy be protected?
Yes. MTC and Caltrans both guarantee that FasTrak™ users will remain anonymous. Encryption software scrambles each FasTrak™ toll tag ID number before any other processing happens; the set of scrambled IDs are discarded every day; and the encryption code is changed every day. No historical database of the encrypted IDs is maintained. No one involved in 511 will ever have access to the FasTrak™ ID number or any personal information related to the toll tag. None of the information collected for Driving Times can ever be associated with a specific FasTrak™ account. Because of these protections, 511 cannot be used to issue traffic tickets or otherwise "track" users.

Read the Privacy Principles that MTC and Caltrans have adopted for the Driving Times service.

Can I elect not to participate in this 511/ FasTrak™ data collection program and still be a FasTrak™ customer?
Yes, if you are uncomfortable with participating in the Driving Times service, FasTrak™ will provide you with a static-shield bag. FasTrak™ has already mailed these bags to its current customers. If you are a new customer or have otherwise not received one of these bags, you can request one, free of charge, by contacting FasTrak™ customer service at fastrak@nac.net. When you insert your FasTrak™ toll tag into this bag, it cannot be read by the 511 antennas. However, you will need to take your FasTrak™ toll tag out of its bag to be read at toll plazas.

Who is responsible for Driving Times?
The Metropolitan Transportation Commission (MTC), in partnership with Caltrans, is bringing you Driving Times. MTC is responsible for the entire 511 project, and funds the 511 telephone number, the 511.org Web page, and all other elements of the project. Caltrans is a major partner in the overall 511 project, and supports Driving Times by contributing information from its embedded detector system and by allowing MTC to install the FasTrak™ readers along Bay Area freeways.

Where do the driving times estimates on changeable message signs come from?
Driving times provided by the 511 service are posted on several dozen changeable message signs around the region. Each sign provides information on three destinations. 511 Driving Times are derived from three data sources: Caltrans in-pavement detectors, radar detector data purchased from a private company, and Electronic Toll Collection readers. You can get driving times for the destinations listed on changeable message signs and many more destinations by calling 511 and asking for "driving times" or going to 511.org and using the interactive traffic map.

Driving times destinations posted on changeable message signs are primarily selected to provide information on heavily traveled routes. Availability of traffic data along the routes is also a consideration. 511 Driving Times on the signs are updated every minute.

The 511 program is administered by MTC. Caltrans and MTC collect traffic data used to generate driving times, CHP provides traffic incident information, and Caltrans operates and maintains the changeable message signs.

Where do I find out more about driving times on the changeable message signs?
Click here to read a fact sheet (PDF).

What are Traffic Messages?
Traffic messages are warnings or information about major incidents that may affect Bay Area traffic. Each message includes a brief title, the date and time the message was posted to the 511 Traffic site, and a description of the incident.

How can I view the site's Traffic Messages?
A selection of the highest-priority messages (i.e., those likely to affect the most people) appears on the 511 Traffic home page located in a box below the Popular Driving Times on the right side of the screen. Clicking on any of these will bring you to the Traffic Messages page, where all Traffic Messages are listed with full details. You also can access the Traffic Messages page by clicking the "Traffic Messages" tool on the left-hand navigation bar.

The Traffic Messages page lists messages in two sections based on priority (High or Low). Within each section the messages are sorted by date and time (starting with the most recent).

What is Predict-a-Trip^SM?
Predict-a-Trip is a feature of the 511 Traffic page that provides typical travel time and speed information for user-selected driving times routes based on historical information. You simply select a driving times route and then select the day of the week and time of day for which you are interested in receiving typical travel times and speeds. Predict-a-Trip helps you plan your driving time IN ADVANCE or your trip. Use Predict-a-Trip for out-of-the-ordinary trips, like dinner at a new restaurant on a Friday night or an early-morning flight out of SFO on Wednesday. If you're thinking of moving to a new part of the Bay Area, Predict-a-Trip can help you estimate the typical morning and evening commute.

What does "typical" mean?
"Typical" is the term used for the historical average driving time and speed between a starting and ending point for a particular day of the week and time of day. For example, when viewing Predict-a-Trip information for Monday at 9:30am, the "typical" values shown for speed and travel times are the averages of conditions on Mondays at 9:30am in the past. The Predict-a-Trip tool uses an averaging scheme that gives more weight to data that is current so that the "typical" values are representative of current, seasonal traffic patterns.

How does Predict-a-Trip^SM work?
The 511 system gathers traffic information from several data sources that are currently measuring traffic speeds and travel times. This information is checked against several quality filters that help to ensure the data is as accurate as possible before it is used by the 511 system. This information is then combined into 15-minute intervals for each day of the week and holiday defined in the system. For each 15-minute interval, a "typical" value is calculated based on historical information. The "typical" value is updated every day using the most recent data to allow the Predict-a-Trip feature to provide the most accurate historical-based travel time and traffic speed information possible for any given day of the week during any of the 96 15-minute segments of the day.

How do I use the Predict-a-Trip^SM feature?
There are several ways to access typical travel time and speed estimates from Predict-a-Trip: directly through the Predict-a-Trip interface, using the text-based driving times feature, on the Traffic and Driving Times Map, and within the Popular 511 Driving Times^SM table.

The Predict-a-Trip interface: Simply select an origin and destination, and Predict-a-Trip provides the typical travel time and speeds for the trips possible for the selected route. The Predict-a-Trip feature always defaults to the current day of the week and current time of day for the initial display of the information. However, you can change the day of the week, the time of day, or both in order to obtain typical information for another day and time.

Text-based Driving Times: Use this tool as you normally would to select your desired origin and destination. The results page will show not only the current travel time and speeds along the route, but also the typical travel time and speeds along the route based on historical information for the current day of the week and time of day. A link is provided from this page to the Predict-a-Trip interface, where you can change the day of the week and time of day for which you want to see the typical travel times and speeds for the selected driving times route.

Traffic and Driving Times Map: Select the driving times tool to choose an origin and destination using the dots on the map. When the results are displayed, the "More details on trip(s)..." link provides detailed information on travel times and speeds for each of the trips, including the typical travel times and speeds. The typical travel times and speeds shown are based on the current day of the week and time of day. In addition, a link to the Predict-a-Trip tool is provided to allow you to select a different day of the week and time of day.

511 Popular Driving Times^SM: If you want to find a typical driving time fast, check the popular driving times listed on the 511 Traffic home page. Typical information is displayed along with the current travel time information. The typical travel time shown is based on the current day of the week and current time of day.

Can I use Predict-a-Trip^SM from the Driving Times Map Feature?
Yes, you simply calculate a driving time as you normally would. Just select the origin and destination to receive travel time information on the various trips and alternate routes. The "More details on trip(s)..." link provides detailed information on travel times and speeds for each of the trips, including the typical travel times and speeds. The typical travel times and speeds shown are based on the current day of the week and time of day. In addition, a link to the Predict-a-Trip tool is provided to allow you to select a different day of the week and time of day.

Why are Tuesday, Wednesday, and Thursday not separate days of the week?
There are currently seven different "day" designations used by the 511 system to categorize historical data. These are Holiday, Thanksgiving, Sunday, Monday, Mid-Week, Friday, and Saturday. Tuesday, Wednesday, and Thursday are grouped together as the "Mid-week" day type due to the similarity in traffic patterns found on these days. Behind the scenes, the 511 system still gathers data for each of these days individually, but then combines the data into one grouping known as "Mid-week."

What holidays are included in the Holidays category?
The holidays that are currently grouped into the "Holidays" category are:

• Martin Luther King Day
• Presidents Day
• Memorial Day
• Labor Day
• Columbus Day
• Christmas Day
• News Years Day
• Independence Day
• Veterans Day

How is Thanksgiving defined for Predict-a-Trip^SM?
Thanksgiving is called out separately from the other holidays due to the fact that the 511 system treats Thanksgiving as multiple days. The Thanksgiving category includes the Thursday and Friday of Thanksgiving weekend.

How accurate is Predict-a-Trip^SM?
The 511 system provides several data quality checks along the path from when the data is collected to when the data is provided to the end user. These quality checks help to ensure that the data you receive from the 511 Traffic web site is as accurate as possible. When using Predict-a-Trip to plan your travel time in advance, it's important to remember that current conditions on the day of your trip may differ from typical conditions. If your trip is very time-sensitive, you may want to allow extra time in case current conditions on the day of your trip are worse than the historical average. You should also check current driving times before taking your trip for the most recent information.

What are the minimum computer specifications required to watch Caltrans streaming video?
MTC recommends the following as a minimum specification for computers on which to view streaming video. Using computers that do not meet the minimum specifications may adversely affect your video viewing experience.

Windows

• Microsoft Windows®: 98SE, 2000, Millennium Edition, XP Home Edition, or XP Professional
  
• The latest versions of Microsoft Internet Explorer, Netscape Navigator, Firefox, or Opera
  
• 128 megabytes (MB) of RAM
  
• Broadband Internet connection or access to a high-speed network
  
• Super VGA (800 x 600) or higher resolution

• Mac OSX
  
• Latest versions of Safari, Firefox or Opera
  
• 256 megabytes (MB) of RAM
  
• Broadband Internet connection or access to a high-speed network
  
• Super VGA (800 x 600) or higher resolution

Do I have to use Windows Media Player to view the Caltrans streaming video?
Yes. Caltrans video requires Windows Media Player. Windows users may be able to watch video using versions 7 or 8, but may be prompted to install Microsoft Windows Media 9 codec. The overall user experience might be less satisfactory.

For optimal performance the MTC recommends you download the latest player. The latest Windows Media Player can be obtained from the Microsoft Download Center.

You can also upgrade to the most recent version of Windows Media Player at any time. Open the Windows Media Player application and select "Check for Players Updates..." from the Help menu (Mac users: select "Check for Player Upgrade" from the Help menu.)

Do I need a specific version of Windows Media Player?
The Caltrans video is best viewed using Windows Media Player version 9 and above.

Windows users may be able to watch video using versions 7 or 8, but may be prompted to install Microsoft Windows Media 9 player. The overall user experience might be less satisfactory.

The latest Windows Media Player can be obtained from the Microsoft Download Center.

My popup blocker won't let me watch the Caltrans videos. How can I fix that?
Pop-up blockers may prevent the video player from opening. Setting your pop-up blocker to allow pop-ups from Caltrans will fix this problem. Please see your pop-up blocker's help section for more information. Many popup blockers can by modified via a "settings," "options," or "block/allow" button.

Why do video clips sometimes stop or pause?
The most common cause of a pause or stop is Internet traffic congestion. If this problem persists, try closing the player, then re-launch it from any video link () on the 511 Traffic Map.

I can open Windows Media Player, but cannot see any video.
A browser error may have occurred. Try closing the player, then reopen it via a video link () on the 511 Traffic Map.

Your Internet Service Provider or corporate IT department may be experiencing problems with their servers. If you cannot view other pages, and if the problem persists, you should contact your Internet Service Provider or your Network Administrator.

If you can access the player on another machine or other people can view it, it may be a problem with your browser cache. Clearing your browser cache is a recommended step to possibly correcting this problem.

Some corporate networks and Internet Service Providers block video transmissions. If you cannot see video clips (even though your system meets the system requirements noted above), you may want to contact your Internet Service Provider or Network Administrator to see whether a security firewall is blocking video transmission.

What if Windows Media Player is not my default player?
If you haven't already, you should download the latest version of Windows Media Player from the Microsoft Download Center.

Once the Windows Media Player is installed, verify that it is defined as the default player for Windows Media format files. Do this by starting Windows Media Player, selecting "Tools->Options..." to bring up the options dialog box, select the "File Types" tab, and then check the box next to "Windows Media file (asf)". Click the OK button and you should be able to view the streaming video from 511.org.

When I use the Traffic and Driving Times Map, why do my browser buttons disappear?
The map is a separate application and thus the normal browser tools are not functional with it. Additionally, the deletion of the browser tools provided more space for a larger map, resulting in greater usability.

However, we have provided functionality that mimics the browser tools of "Back" and "Refresh". If you need to go back to the traffic home page, just close the map window. If you need to update the map's information, you can do so at any time by clicking the "Refresh Map" tool located in the Map Tools bar.

How come when I click on an incident, event, construction, or color-coded roadway on the map, I do not see any information in the Information Detail Box?
Before you click on any icons on the map, make sure you have selected the "Information" tool from the Map Tools bar. If you have selected this tool, the button will appear yellow in the Map Tools bar. If it is not selected, the button will be white and will not work to provide information on the icons.

I made a mistake when I picked my starting point circle. What do I do now?
If you picked the wrong starting point while using Driving Times, just click on the "Cancel driving time calculation" link shown in the Information Detail Box, located in the upper, right-hand column of the page. This will cancel the Driving Times feature and select the Information tool. To start over with another Driving Times request, select the Driving Times tool again and click a starting point.

What if I want more information or I want to talk to someone at MTC?
You can email MTC at 511traffic@mtc.ca.gov with any additional questions or comments or call our comment line at 510-817-3278.

What are cookies and why are session cookies used on the 511 Traffic Web site?
Cookies are a small amount of data sent to your browser from a web server and stored on your computer's hard drive. The 511 Traffic Website uses session cookies and persistent cookies. Session cookies expire after the user exits the web site, or shortly after, and are not generally considered to be a privacy or security concern. Persistent cookies tend to have a longer life-span and are used to retain user session information such as settings and configuration parameters. Cookies are unique to each web site and information in them cannot be accessed by other web sites. The cookies utilized by the 511 Traffic Website do not provide any personal information about the user and are only used to enhance the user's experience with the 511 Traffic Website. Please refer to the privacy page for more information on the use of cookies.

Sometimes the traffic data seems to be different in the different browser windows.
There may be times when you are using the 511 Traffic Web site that you have multiple browser windows open. An example would be when displaying the detailed information of a driving time route that was generated through the use of the graphical map tools. Each browser window is refreshed based on the refresh interval selected by the user and this interval starts at the time the browser window was first displayed. Therefore, there may be times when one browser window has refreshed based on its refresh interval and initial display time, but the other browser window has yet to reach its refresh interval time.

Why can I use everything on the web site except 511 Driving Times^SM?
It is because you are not using a browser version designed for the 511 Traffic web site. The 511 Traffic web site is designed to work with Internet Explorer 5.5 and Netscape 7.0. Many features of the web site are accessible on older browser versions, but to enjoy all of the traffic site's features you may need to download the latest version of your favorite browser. To download the latest version of Internet Explorer, click here. To download the latest version of Netscape, click here.

Why does the traffic map show up as all black in my Mozilla browser window?
It has been determined there are known compatibility issues associated with displaying images in Mozilla on Windows 98. Using Windows 98 with some ATI graphics adapters can result in corruption of images as rendered on web pages. Mozilla has recognized this problem as an ATI graphics driver bug. For more information, access the Mozilla bug list at http://www.mozilla.org/releases/mozilla1.6/known-issues.html#browser.

To use the map try a different browser such as Internet Explorer - Version 5.5 or higher or Netscape - Version 7.0 or higher. To download the latest version of Internet Explorer, click here. To download the latest version of Netscape, click here.

I keep getting "Invalid width of IMAGESIZE" errors when I use Safari to view the detailed traffic map
There is a known issue with the Safari browser which manifests itself as an error message stating "Invalid width of IMAGESIZE". There is currently no known workaround for this problem other than using a different browser. The 511 Traffic team is investigating this issue and attempting to correct the problem as quickly as possible.