Travel Midwest Glossary
| Term | Definition |
|---|---|
| *999 | Cellular motorist assistance phone number center for the Chicago Metropolitan area. Cellular calls to *999 are free of charge with underwriting provided by cellular service providers. Calls are redirected to a central location and information is passed to appropriate authorities. Mostly used to report traffic situations or travelers in need of assistance. |
| 1/2 Entrance (closure) | Indicates a partial closure of an entrance ramp. Traffic is still able to pass. See also Entrance Ramp. |
| 1/2 Exit (closure) | Indicates a partial closure of an exit ramp. Traffic is still able to pass. See also Exit Ramp. |
| Advanced Traffic Management System | Regional systems aimed at optimizing traffic flow for a set of roads or the entire region. Elements typically include sensors to monitor traffic flow, centrally programmable traffic signals, automated highway signs, computers and telecommunications technology. |
| Advanced Traveler Information System | System which provides travelers with information designed to help them plan routes. This information can be web-based traffic information, broadcast traffic reports, in-car computerized maps and dynamic message signs. |
| AMTRAK | Informal name for the National Railroad Passenger Corporation created by the federal government to operate the nation's intercity passenger rail services. |
| ATIS | See Advanced Traveler Information System. |
| ATMS | See Advanced Traffic Management System. |
| Attenuator | A traffic barrier designed to compress under impact. |
| Borman ATMS | An Advanced Traffic Management System operated to manage traffic on the Borman Expressway (I-80/I-94) in Northwest Indiana. |
| Camera Image | The video image provided by a video camera. The camera image may be full motion video, some form of compressed video (size or content modified to make the image data smaller) or "snapshots" or still frames from the video camera. |
| CDOT | Acronym for Chicago Department of Transportation. |
| Chicago 911 | The 911 system operated by the City of Chicago. |
| ComCenter | Refers to the communications center operated by IDOT District 1 (Northeastern Illinois region). The ComCenter coordinates activities on IDOT roadways and provides planned construction activity information. |
| Confidence | A measure of how reliable a piece of information is. For the Travel Midwest web site, information provided by government agencies (transportation departments, police dispatch agencies, etc.) is deemed to have a high confidence, while unconfirmed reports from citizens (for example, from *999) are deemed to initially have low confidence until is it corroborated by surveillance systems, government agency personnel, or additional citizen reports. |
| Congestion | A measure of the amount of traffic on a roadway. Determined by the detected average speed of vehicles on the roadway as ascertained by roadway detectors. |
| Connector Ramp | A ramp leading from one highway to another highway. |
| Cookies | A technique for web sites to store information for a user on the users system so that that information can be retrieved on subsequent visits to the pages of the website. |
| CTA | Acronym for Chicago Transit Authority. |
| DOT | Acronym for Department of Transportation. |
| Delineator | Objects which help drivers recognize the edges of lanes or of the roadway. May either be permanent or temporary. |
| Detector | A device for recognizing the presence and/or the motion of vehicles in a section of the roadway. |
| Duration | The length of time a particular event will take place. For construction, the expected duration is reported by the DOT. For incidents, durations are estimated based on the available information regarding the severity of the incident. |
| DMS | Acronym for Dynamic Message Sign. |
| Dynamic Message Sign | A sign positioned to be readable from the roadway which can be modified to show different messages, usually through electronic means and often from the owning ATMS or ComCenter location. Messages can therefore be changed to reflect current traffic conditions. |
| Entrance Ramp | A ramp leading onto the highway. |
| Exit Ramp | A ramp leading off of the highway. |
| GCM Corridor | See Gary-Chicago-Milwaukee Corridor. |
| Gary-Chicago-Milwaukee Corridor | The ITS High Priority Corridor established by the Federal Highway Administration in 1993. This corridor consisted of 16 urbanized counties and 2,500 miles of roadways connecting the three cities. The 16 counties included Cook, DuPage, Lake, Kane, McHenry, and Will in Illinois, Lake, LaPorte, and Porter in Indiana, and Kenosha, Milwaukee, Ozaukee, Racine, Walworth, Washington, and Waukesha in Wisconsin. The Corridor included all expressways, tollways, major arterials, airports, transit facilities, ports, and rail systems within these 16 counties. |
| High Congestion | A congestion status where a considerable amount of congestion is detected. Indicates low speeds and a high volume of vehicles. |
| ISP15 | See Illinois State Police, District 15. |
| ITS | See Intelligent Transportation Systems. |
| Illinois DOT | Acronym for Illinois State Department of Transportation. |
| Illinois State Police, District 2 | Illinois State Police division covering the counties of: DeKalb, DuPage, Kane, Lake and McHenry |
| Illinois State Police, District 5 | Illinois State Police division covering the counties of: Grundy, Kendall and Will. |
| Illinois State Police, Chicago District | Illinois State Police division covering Cook county and the City of Chicago. |
| Illinois State Police, District 15 | Illinois State Police division covering the state tollways in the Northeastern part of Illinois. |
| Illinois Tollway | Operates tollways in the North and Northeastern part of Illinois. |
| Inbound | Used in the Chicago Metropolitan Area to indicate roads which lead from outlying areas into downtown Chicago. |
| Indiana DOT | Acronym for Indiana Department of Transportation. |
| Intelligent Transportation Systems | Application of information and communications technology to vehicles and surface transportation systems to improve safety, efficiency and system performance. ITS goals include alleviating traffic congestion, preventing and reducing the severity of crashes, using energy more efficiently, reducing emissions, and improving access to transit and multimodal transportation alternatives. |
| JavaScript | A scripting language provided by the users browser which enables web page authors to create more dynamic, visually pleasing, and easy to use web pages. |
| Light congestion | A congestion status where only a small amount of congestion is detected. Speeds are not free flowing, but are not greatly reduced. |
| LMIGA | Acronym for Lake Michigan Interstate Gateway Alliance. The Lake Michigan Interstate Gateway Alliance (LMIGA) Is a voluntary organization with active member participation from the Wisconsin Department of Transportation, the Illinois Department of Transportation, the Indiana Department of Transportation, the Michigan Department of Transportation, the Illinois Tollway, the Skyway Concession Company LLC, and the Indiana Toll Road Concession Company LLC. |
| Medium congestion | A congestion status where a noticeable amount of congestion is detected. Drivers will encounter some speed reductions. |
| Message Sign | A sign positioned to be readable from the roadway. See also Dynamic Message Sign. |
| MCTS | Acronym for Milwaukee County Transit System. |
| Milwaukee County Transit System | Operates public transit facilities and vehicles in the Milwaukee area. |
| METRA | Operates commuter rail facilities and rolling stock in the greater Chicago area. |
| Moving Operation | Construction or road maintenance operations which move along the roadway as they proceed. Only the section of the roadway currently being worked on is usually closed off or otherwise affected by the operation. |
| NWCD | Acronym for Northwest Central Dispatch. |
| Northwest Central Dispatch | A centralized computerized police and fire dispatching organization for 11 communities in the NW suburbs of Chicago (Arlington Heights, Buffalo Grove, Elk Grove Village, Hoffman Estates, Inverness, Mount Prospect, Palatine, Prospect Heights, Rolling Meadows, Schaumburg and Streamwood). |
| Occupancy | The percentage of time a detector registers the presence of a vehicle within its range of detection. This value, along with volume, is commonly used to determine road congestion and speed. |
| Outbound | Used in the Chicago Metropolitan Area to indicate roads which lead from the Chicago downtown to outlying areas. |
| Point Construction | Construction or other road work which occurs in a small, centralized area, rather than along a long stretch of the roadway. |
| Real-time | Implies that information is updated with sufficient frequency that it should give a reasonable estimate of the current conditions. On this site, information is noted as "real-time" but may still demonstrate a certain amount of delay (from communication delays, verification delays, etc). |
| Rehabilitation (Rehab) | Refers to repair of a road surface or other related structure. May involve everything from simple patching to replacement of the surface. The result is a surface with conditions similar to those when it was newly made. |
| Scupper (Cleaning) | A scupper is a water drain which runs under the surface of the road or roadside curb or sidewalk. Scupper cleaning refers to the removal of objects lodged in the drain, such as leaves, branches, and other debris. |
| Section Construction | Construction or other roadwork which stretches along a roadway for a significant distance. Traffic on the roadway may be affected by the work along the entire distance of the work area. |
| Shoulder | The side of the roadway, outside any of the designated lanes. May be paved, gravel, grass or other surfaces. |
| Snapshot | Refers to a still image created by a motion video camera. Because of the high bandwidth needed to transfer moving images, traffic images provided to the public are often recent "snapshots" taken from the motion video image produced by the camera. |
| Striping | Painting of road way stripes, or the repainting thereof. |
| TIM | Traffic and Incident Management. |
| Travel Midwest | Provides information about current traffic conditions and links to other sites for the coverage area that includes the following counties:
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| Uncongested | A congestion status where no appreciable congestion is being detected. This is not to say there is no congestion on the roadway, only that the roadway detectors are not currently registering detectable congestion. Traffic is likely free flowing. |
| Volume | The number of vehicles that pass a roadway location during a period of time. Often expressed in the number of vehicles per hour per lane. |
| Wisconsin DOT | Acronym for Wisconsin Department of Transportation. |
| WISDOT State Traffic Operations Center | Operates an Advanced Traffic Management System to manage traffic on the Wisconsin freeway system. |