WB US-20 exit ramp to NB I-39 closed July 15 to fall 08. WB exit ramp to SB I-39 remains open. Posted Detour keeps traffic in interchange: Continue WB on US-20 & exit at SB I-39. Take SB I-39 & exit at EB US-20. Take EB US-20 to NB I-39.

Map Help

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The GCM Travel site provides for graphical display of traffic information on 4 maps. These maps are generated by the GCM site and display up-to-date traffic conditions in the form of colored areas and icons. The maps provide a way for you to quickly get a picture of the current traffic conditions in the Corridor.

Maps are accessed through the "Maps" item in the menu bar. The GCM Travel site provides 4 maps for the user, ones centered around the Greater Chicago area, the Gary area, and the Milwaukee area. The fourth map can be used to display information about the entire corridor.

Information on the maps is provided in layers. Layers may be turned on or off to allow you to remove clutter from the map, or to concentrate on information you find more important. Initially all layers will be on. As you turn layers on and off, information about your preferred layers will be saved using browser cookies. If your browser does not support cookies (very rare) or you have cookies disabled, then you will not be able to use the layer feature.

All the maps on the GCM Travel site can be scrolled and zoomed to allow you to view the area you are interested in. When you initially view the map, a default zoom level and map position will be displayed which has been selected by the site developers.

When you scroll and zoom a map to a particular view, the location and zoom information is stored in a cookie on your browser. In this way, you can refresh the map to update its real-time information without losing track of the area you were viewing. The layers that you have chosen to view are also saved. The cookie is maintained so your preferred viewing area will be ready to use when you return to the site.

Because of the size and complexity of the maps, the time it takes to generate them and send them from the GCM Travel site server to your browers may be noticable. Please have patience as the maps load.

Once you have selected a map, you will see a page much like the one below (this one is the Chicago map).

The main sections and featurs of the map page are as follows:

  1. Main Map Display - This area shows the detailed information map with the currently selected layers, at the current zoom level and scroll position.
  2. Mini Map - This area provides a smaller map of the corridor area. Clicking on this mini map will cause the redisplay of the main map centered at the same position that was clicked on the mini map.
  3. Map Legend - This area describes the icons and colorizations used on the Main Map.
  4. Zoom Controls - These three objects are controls to cause the Main Map display to zoom in and out, and to reset the map to its default zoom and extent. To use these controls, position your mouse over the control and click. As it takes some time for the map to redisplay, please be patient and try not to click multiple times.
  5. Layer Controls - These objects control which layers are to be displayed on the Main Map. To operate a control, position your mouse over the control and click. Again, the map may take a while to reload, so your patience is appreciated. If you hover your mouse over the control (without clicking) a small pop up (tool tip) will appear (on most browsers) which will indicate what layer the object controls and whether that layer is currently being displayed or not. In order from left to right the controls affect the following layers: Construction, Road Signs, Congestion, Incidents, Travel Times, Airports, Message Signs, and Cameras
  6. Scroll Controls - These objects (labeled "Scroll North", "Scroll East", "Scroll South" and "Scroll West") cause the Main Map to scroll to display an area farther in the direction selected. That is to say, if you click on "Scroll North" the Main Map will be redrawn to include areas to the north of those currently displayed. The amount scrolled will depend on how far in our out you have zoomed the map. The map will scroll so that, in the example of picking North, the current North edge of the map becomes the South edge. The map will not scroll beyond the corridor, and in the case where the Corridor edge is encountered, may not scroll the full amount.
  7. Incident Icon - This icon indicates that there has been an incident reported at this location which is believed to still be currenlty affecting traffic conditions at that point. The level of the effect will, of course, vary from incident to incident. Clicking on an incident icon will popup a new window with more detailed information about the selected incident.
  8. Section Construction - The jagged orange lines next to a roadway indicate that there is construction or maintenance activity along that roadway for the entire length that is indicated by the jagged orange icons. In some cases, indicated by a darker orange, this construction activity might be moving along the section indicated, so that the entire section is not affected. In other cases, indicated by the lighter orange, the whole section is most likely being affected by the construction or maintenance activity. Clicking on the section construction icon will popup a window with more information about the selected construction.
  9. Point Construction - These cone icons indicate a construction or maintenance activity is taking place at the location indicated by the icon. In the case of point construction, the activity is occuring in a small area and not along any long length of roadway. Clicking on a point construction cone will popup a window containing more information about the selected construction.
  10. Congestion Colorization - The coloring of the major roadways indicates the detected congestion (based on the speed of vehicles on the roadway) of that roadway area. The colors range from dark green (uncongested) to red (heavy congestion). Only roadways which are equipped with congestion detection equipment are colored in this way. If a roadway has such equipment, but the GCM Travel site is unable to determine the current congestion (possibly because of a communication error) the roadways are colored gray. Roadways which have no detection equipment are shown as thinner lines on the map. Clicking on a colored congestion segment will popup a window displaying more detailed information.
  11. Airports - The icon of a plane indicates the position of airports within the area displayed on the Main Map. Clicking on an airport icon will allow you to view the home page of the respective airport.
  12. Transit Icon - Clicking on this icon will display public transportation facility information for the area displayed on the Main Map.
  13. Road Shields - The numerical designations of major expressways and tollways and certain other roads displayed on the Main Map are shown using these road shield icons.
  14. Travel Time Icons - These icons display the up-to-date travel times. In the Chicago area, these icons display the travel time to and from the Chicago downtown area to the location of the icons (the arrows indicate the direction of traffic, so blue arrows show direction towards the downtown, and while arrows show direction away from the downtown. In the Milwaukee area, the travel times icons show the travel time between major interchanges in the Milwaukee area. Again, the arrow indicates the direction of the traffic flow for which the time is provided. Clicking on these icons will popup a window containing more information about a traffic on the selected route.
  15. Civic Borders - The background of the map is colored to show the different counties being displayed.

Note that clicking anywhere on the main map will cause a window to popup to display more information about the point on the map that your cursor was at when you clicked.

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Fri Jul 25 20:47:04 CDT 2008