Frequently Asked Questions

The following are some Frequently Asked Questions about the GCM Corridor web pages. Each question is a link to the answer below.

28. I would like to evaluate alternative routes to plan my commute or a trip. How can I obtain information about the typical travel times on various routes?

29. Why are the Illinois Tollway congestion levels and travel times sometimes lessaccurate?

30. I didn't see my question. What do I do?

1. What is the CGM Corridor?

The GCM Corridor (Gary Chicago Milwaukee) Corridor is a high traffic area previously designated by the US Department of Transportation as a Priority Corridor. Because of population and traffic in the original three-state area of Illinois, Indiana, and Wisconsin the Corridor is being expanded into Michigan and is being renamed the Lake Michigan Interstate Gateway Alliance (LMIGA). Look for the labels on the GCM Travel website to reflect this new name in the future.

The Interstate highways including Tollways and major arterials in Illinois, northwestern Indiana, and southeastern Wisconsin are covered by this system. Cook, DuPage, Lake, McHenry, Kane, and Will counties in Illinois, Lake, LaPorte, and Porter counties in Indiana, and Kenosha, Milwaukee, Ozaukee, Racine, Walworth, Washington, and Waukesha counties in Wisconsin are included in the primary coverage area.

This information is made available on the GCM (LMIGA) Gateway Traveler Information System as a service to the traveling public at no cost.

2. What is the coverage area of the GCM Travel web site?

The original GCM Corridor consists of the 16 urbanized counties in the Gary-Chicago-Milwaukee area:

Cook, DuPage, Lake, Kane, McHenry, and Will in Illinois
Lake, LaPorte, and Porter in Indiana
Kenosha, Milwaukee, Ozaukee, Racine, Walworth, Washington, and Waukesha in Wisconsin

Recently the site's coverage area has been expanded to include the following counties:

Boone, Bureau, Carroll, DeKalb, Grundy, Henry, Jo Daviess, Kendall, La Salle, Lee, Ogle, Rock Island, Stephenson, Whiteside, and Winnebago in Illinois
Elkhart, LaGrange, St. Joseph, and Steuben in Indiana
Dane, Green, Jefferson, Lafayette, and Rock in Wisconsin
Allegan, Barry, Berrian, Branch, Calhoun, Cass, Eaton, Kalamazoo, St. Joseph, and Van Buren in Michigan

The map below shows the GCM Travel web site coverage area:

3. Why is the GCM (LMIGA) Travel site unique?

There are several websites which have pieces of information for different parts of the GCM (soon to be LMIGA) Corridor area, but the GCM (LMIGA) Travel Gateway is one place where information on the entire area is available in driver-friendly formats and can be linked to easily. Sometimes construction or an accident in another state affects the highways in your state. GCM (LMIGA) gives you the picture across state lines. Unlike many other sites, the Gateway also has an open policy on sharing the traffic information at no charge.

4. Where does the information come from?

The system receives traffic data from all major traffic management systems in the area, including Illinois Department of Transportation Traffic Systems Center, Wisconsin's' MONITOR system and the Illinois Tollway. These systems use a wide range of traffic detection technologies to monitor speed and concentration of vehicles. Based on the collected data, traffic congestion levels and travel times are computed. These systems also provide messages currently displayed on dynamic message signs. locatred along the roadways.

Most information about incidents and construction-related road closures is manually input by GCM (LMIGA) operators from a series of reports. There are some automated accident entries, but most are manually entered.

This blend of automatic data and manual entry help to keep the information available to drivers as current and accurate as possible.

5. How does automatic traffic data get to the system?

There are currently many types of vehicle sensors available, including inductive loop, microwave radar, infrared, ultrasonic, acoustic, and video image processing. There are embedded in-roadway sensors and above-roadway sensors. The GCM (LMIGA) System has a blend of both types. In general, these sensors detect the presence and passage of vehicles.

The collected data is transmitted from the field via a variety of communication links to a central control system, where it is further processed and distributed.

6. How can I view a map of my preference without zooming and scrolling one of the maps from the "Maps" menu?

The GCM Travel web site home page now presents a map. As you scroll and zoom that map and turn layers on and off, the location, zoom and layer information is stored in a cookie on your browser which is retained for three months. When you return to the site home page or select "My Map" from the "Maps" menu, the saved map configuration will be displayed.

7. Why does the travel time and congestion information disappear when there are major construction projects, when we need the information the most?

Unfortunately, most major construction projects involve removal of the existing roadbed and other activities that interrupt the operations of the traffic sensors and / or their communication to the central control system. Once the construction activities are over, operation of the affected traffic sensors are restored. Until then, there is no way to get the data.

Occasionally, a project will allow for the installation of temporary sensors to fill the gap during construction, but this is not always feasible. Every effort is made to bring the sensor systems back into operation as soon as possible.

8. Is the Miles Per Hour (MPH) given the minimum, maximum, or actual speed?

The reported speed is an estimate based on traffic sensor data, and it is re-calculated at various intervals ranging typically from one to five minutes.

9. How current is the information listed on the website?

The currentness of the information on the web site varies by type of information and also by source.

Incidents are input into the system and updated manually by the GCM operators. There is some delay because incident information needs to be manually collected and verified.
Construction information is entered manually by the GCM operators at a daily basis.
Traffic updates are automated and comes at various intervals with a typical frequency of once every five minutes.
Dynamic message sign updates are also automated and typically occur whenever there is a change to the message.

10. I see construction indicated on the map, where can I get more information?

You can view construction reports by accessing the Construction menu item on the Reports menu on the GCM (LMIGA) Travel site. You can get a short summary of work planned on all of our covered highways and roads. Additional information on slightly more involved items may be found in the GCM Travel Home Page or in the Announcements Section. Many of the major long-term projects such as the reconstruction of an entire interstate section have their own websites. The Projects menu includes menu items which link to the websites of such projects. In addition, the Links page has the links to the individual state Department of Transportation sites where even more extensive information is available.

11. Does the site have driving directions?

No. The GCM (LMIGA) Travel site has information on the interstates, tollways, and a few limited access highways. To be truly useful, driving directions need information on other roadways not currently included in our data. You can access several of the sites that have driving instructions, though many do not have the congestion and construction information, from our Links page. These sites are www.mapquest.com, www.mapsonus.com, www.zip2.com, www.mapblast.com, maps.google.com, maps.yahoo.com and expediamaps.com. Links are continually being added to this area for the convenience of our users. If your favorite site is not included under the Links section, use the Contact Us page to send an email to the GCM webmaster telling us about the pages you would like to see included.

12. Are you planning to add arterial streets or other highly traveled roads?

The GCM (LMIGA) Travel site does currently provide traffic data on some arterials, e.g. Lake Shore Drive and US-41 in the Milwaukee area. The system has the capability to maintain and display events on arterials, and will be doing so soon for Lake County Illinois. However the addition of travel times for arterial streets depends on automatic equipment in or near the roadway and the ability of the managing agency to transmit the data to the Gateway. Since arterials are under the control of numerous agencies and jurisdictions that often do not have the resources to implement these capabilities, there are no current plans to add arterial streets to the site.

Though travel time is not included for arterials, major construction information is included on the Announcements and Reports pages if the construction impacts roads covered by the GCM (LMIGA) system. Construction and major incident information is also included for interstates outside our normal coverage area that could have an effect on our area.

13. Do you have bus and train information in addition to road information?

You can access bus and train information through the Links section that provides links to all of the transportation agencies in the coverage area. Transit and Intercity Rail sites are grouped by state. There are plans to add transit incident and service disruption information to the site sometime next year.

14. Does your site list airport parking information?

You can access individual airport websites through the Links page of the GCM (LMIGA) Travel site. Each airport in the region has a website with driving instructions from major interstates, and parking data. The airport sites contain parking restrictions, cell phone lots, and other special instructions that visitors to the airports will need. The Links page of this site has links to all of the airports in the region with scheduled air service.

15. What do the road colors on the map mean?

The colors on the map are designed to give a quick visual picture of the state of the covered roadways. Each color represents an estimated level of congestion on that road segment. The levels of congestion are:

16. Why doesn't anything happen when I click on an icon on the map?

The GCM (LMIGA) Travel site uses popups to display certain pieces of information. Some pages may not load properly if your browser is using a "popup blocker". You can override this in many cases by holding down the Control (Ctrl) key while clicking on the icon you wish to access. Many "popup blockers" can be turned on and off. A number of popup blocking systems also allow you to add specific websites to an approved list so that popups are allowed for those listed sites only. Make sure that your browser allows popups when you access the site. Check the Requirements page to see if your browser is blocking popups.

17. Why do some pages look strange or not come up properly?

The GCM (LMIGA) Travel site is designed to work primarily with popular browsers such as Microsoft Internet Explorer, Mozilla, Firefox, and Safari.

18. Can I access GCM (LMIGA) Travel information on my PDA or cell phone?

Yes. However, you must make sure that your phone is compatible with web access and that your cellular service provider offers this service. While the GCM (LMIGA) Travel information is offered free of charge, your cellular provider may have a charge for connecting to the web.

The Illinois Department of Transportation provides the 'beta' availability of a wireless-friendly version of Chicago Area Travel Times as part of the overall traveler information services. This new feature is an extension of our existing Chicago Quick Traffic Report, available at ChicagoQuickTraffic.jsp, that displays travel time information of common regional interest. If your mobile device supports Wireless Markup Language version 1.1 (WML 1.1) and Wireless Application Protocol 2.0 (WAP 2.0), you can access this service at www.gcmtravel.com. You can then navigate through a list of Expressways and Tollways to access a list of travel times for the chosen route.

We anticipate that most users will have no trouble with the new page. We ask that those experiencing difficulty with the new wireless report to email us at GCM webmaster. Include your cellular service provider and device make and model to help us identify any issues.

This feature is not intended for use while operating motor vehicles. Please drive safely and responsibly.

This information is also on the Announcements page of the GCM (LMIGA) Travel site. Every effort will be made to ensure that the GCM (LMIGA) Travel site is compatible with new wireless devices.

19. Can I get timely traffic information sent directly to me without having to go the web to get it?

In the Chicago area, the Illinois Traffic Alert System (ITAS) provides customized traffic reports containing vehicle speeds, travel times, construction, congestion and incident information through your e-mail inbox, cell phone text messaging, or other e-mail enabled mobile device. You can register for the ITAS service at ITAS registration. You will be prompted to select the days, times and roadways for which you desire information.

20. I thought I signed up for the Traffic Alert System, but I am not receiving anything. What should I do?

The registration process for the Illinois Traffic Alert System (ITAS) requires an email registration verification. After completing the registration form, you will receive an email at the registered email. You will be directed to link to the registration site and enter the code contained in the email to complete the registration. This is to ensure that only those who want to receive the email notifications receive them. You must enter the code from the email to begin receiving the notifications. If you do not receive the email, you should check your spam filter to insure that the confirmation emails are not being treated as spam.

21. How do I report a pothole?

In the Chicago area, you can report potholes on expressways including toll roads to the *999 Cellular Express Line. As a general rule, report potholes on expressways and state owned roads to state DOT, others to the public works department of the local municipality.

22. How do I report debris in the roadway?

You can report debris to the *999 Cellular Express Line in the Metropolitan Chicago Area. Outside of the Metro Chicago Area, contact the public agency that is responsible for operating / maintaining that specific roadway. You can find some of those agencies using the Links page of this website.

23. What do I do if I see an accident or incident on the roadway?

Call 911 for emergencies and accidents.

24. What do I do if I have a question or comment on the GCM (LMIGA) Travel site?

For technical assistance with this website, you can use the Contact Us item on the Help Menu of the GCM (LMIGA) Travel site to contact the webmaster. Questions and comments regarding Intelligent Transportation Systems in Illinois should be directed to the Illinois Department of Transportation ITS Program Office at (847) 705-4800.

25. Can my organization access the GCM (LMIGA) Corridor raw data?

Yes. Organizations may use the data on this site in accordance with the policies outlined in the Traffic Information Access / Reuse Policy. View the Site Policies page by selecting the Policies menu item on the Site Info menu. That page includes a link to a registration form that you can complete to gain access to the data via a Common Object Request Broker Architecture (CORBA) connection to the GCM Gateway Server or downloads in XML format. The registration form includes a link to the Traffic Information Access / Reuse Policy which gives a complete explanation of the rules and guidelines governing use of the data.

26. Is the raw data offered by GCM (LMIGA) Travel available electronically?

Providers of transportation information may be interested in establishing a direct Common Object Request Broker Architecture (CORBA) or XML connection to the GCM Gateway Server. Inquiries regarding direct connections to the Gateway Server should be directed to the GCM Webmaster via the Contact Us menu item on the Help menu of the GCM (LMIGA) Travel site.

27. How do I know if the travel times I am seeing on one of the highways included in your website are high, low, or average?

Historical travel time data for comparison to real-time conditions is available on our companion website, GCM Travel Stats. You can access GCM Travel Stats at http://www.gcmtravelstats.com or via links on the Travel Time Report page and on the small window that is displayed when you click on a travel time icon on a map.

28. I would like to evaluate alternative routes to plan my commute or a trip. How can I obtain information about the typical travel times on various routes?

Historical travel time data is available on our companion website, GCM Travel Stats. You can access GCM Travel Stats at http://www.gcmtravelstats.com or via links on the Travel Time Report page and on the small window that is displayed when you click on a travel time icon on a map.

29. Why are the Illinois Tollway congestion levels and travel times sometimes less accurate?

The GCM system gets data from a variety of sources - Illinois DOT, Illinois Tollway, Indiana DOT, etc. Those agencies use a variety of mechanisms to provide their raw data - pavement loop detectors, transponder toll tag timestamps, etc. In the case of toll tag transponders, the data is by nature more coarse and potentially less timely than direct roadside-based systems. In particular, these data can suffer from latency issues because of delays in receiving the same. For example, if motorists are delayed by heavy congestion, the system is initially unaware of this problem until the motorist passes through the congestion and reaches a toll plaza (or exit) where the toll tag is read. That situation inevitably results in extra delay before the end point timestamp is read. Additionally, the system is unable to determine the precise location of congestion since the data only indicate a delay between two points sometimes spaced far apart (for example 2 toll plazas). This results in long map segments with the same color congestion coding.

The Illinois Tollway is expanding the sources of data used to provide travel times to the Gateway which will allow more granular congestion data to be presented in the future. At a minimum, congestion data will be provided between entrances and exits to the system.

30. I didn't see my question. What do I do?

Not every possible question is listed here, just some of the most common ones. Please click here to send a message to the GCM Travel Team. A team member will get back to you.

Site Sponsors | Requirements | Policies | Disclaimer | Contact Us

Please send comments, suggestions, or requests for help to GCM webmaster.
This site is best viewed in Internet Explorer 6.0+ or Firefox 2.0+ with cookies and Java Script enabled.

Tue Mar 09 17:39:17 CST 2010