The city of Chicago is developing an enterprise-wide urban GIS and Emergency 911 system that may serve as a model for other budget-wary cities. Nearly everyone in the Windy City participates in or benefits from the GIS. City depart-ments will experience better coordination in planning and construction projects. Taxpayers will receive quicker responses to 911 calls and see their tax dollars spent more efficiently. And even some budding GIS technicians at a local high school earned money towards college by assisting in the project.
      Involving high school students in the GIS development was an innovative gamble by the city's GIS committee that has paid off in many ways. By teaching students from Whitney Young High School in downtown Chicago how to perform map digitization in AutoCAD, the city defrayed nearly $1 million in project costs.
      "We wanted to use resources here in the area," said Mark Andersen, vice president of information services at Environmental Systems Design (ESD), the Chicago firm that supervised map automation for the project. "Kids are pretty sharp with computers these days so we decided to get them involved."
      A total of 15 students were hand picked to assist in the digitization. Besides learning a valuable skill, they received $2 per hour in an escrow account towards their college tuition. Another benefit was career guidance from managers and technicians at ESD. They acted as mentors for the students, helping them complete school projects and choose colleges.
      In the overall scheme of Chicago's $217 million GIS and Emergency 911 project, the financial impact of the student program is minor, but the political windfall was significant - and by no means accidental. In this era of municipal budget cutting, big ticket projects like city-wide GISs face scrutiny from local governments and taxpayer groups. GIS projects often become easy targets of criticism and funding cuts when a substantial portion of their expenditure leaves the local economy to purchase less expensive digitizing and scanning services in other countries.
      Chicago avoided sending digitizing work out of the area by initiating the program with Whitney Young and in the process picked up substantial political support. Getting the school involved made the GIS - and its price tag - easier for the local government and taxpayers to accept.

Benefits of Enterprise-Wide GIS
Better coordination among city departments is the main benefit of creating an enterprise-wide GIS accessible to many city agencies and offices, explained Don Bright, principal systems engineer in Chicago's Management Information Systems office. MIS has been assigned the lead role in building and maintaining the GIS database.
      Coordination of projects will make the city operate more efficiently and will save money, said Bright. The city expects the GIS will pay for itself in 10 years.
      The centerpiece of the GIS is a smart map that has been dubbed the "Unimap" because it contains infrastructure elements and attributes relating to eight city departments - Planning, Transportation, Water, Sewer, MIS, Budget, Police, and Fire.
      Digital mapping is not an entirely new experience in the city. The Planning Department has used and updated a digital map for a decade to maintain rights of way. This map serves as the basis for the Unimap.
      Having the elements of all city infrastructure - roads, rights of way, pipelines, and buildings - on one map makes it possible for the different departments to see exactly how their work relates to other departments, said Bright. And this makes coordination much easier.
      He gave as a hypothetical example the Water Department planning the scheduled replacement of a water main. These large underground pipes are replaced periodically to avoid having them rupture unexpectedly during cold weather. When the Water Department shuts down a city street and cuts through the asphalt to gain access to the main, it is a perfect time for the Sewer Department to replace its pipes which lie beneath the water lines.
      Unfortunately, if the Sewer Department doesn't know that Water is excavating the street and doesn't perform the work then, it may be precluded from maintaining its own pipe replacement schedule later on. Chicago has enacted a moratorium on opening streets more often than every six years, except in emergency. If the Sewer Department plans to run new pipe two years after the Water Department, Sewer will be out of luck due to the moratorium, said Bright.
      The same type of coordination is needed with the Transportation Department which repaves streets on a regular basis. City tax dollars can be lost if new asphalt is laid and then torn up six months later to install a new water pipe. The GIS makes it possible for all departments to be aware of when and where construction is occurring and how projects may conflict or complement each other.

Building the GIS from Existing Maps
A key cost-saving ingredient in building the Chicago GIS has been taking advantage of existing resources rather than starting from scratch. For this reason, the Planning Department's digital right-of-way map serves as the base layer upon which all other information is being built. In addition to rights-of-way, this map contains block face outlines acquired from aerial photographs and construction surveys. The department created the map with Intergraph's MGE GIS and uses that software for much of its design work.
      A computer-aided dispatch system for handling emergency 911 calls is being built as the GIS is developed. This system incorporates much of the same map information that will be used in the GIS. The 911 system includes a map display to show dispatchers where an emergency call is originating from. Use of the display map requires updated street centerline information for the entire 228 square mile urban area.
      The Planning Department at one time had created street centerline maps in digital formats but did not keep them updated. Rather than re-map the entire city, Environmental Systems Design used the up-to-date right-of-way maps to correct the outdated centerlines.
      Working in MGE on NT workstations, ESD superimposed the two maps on the display screen. Technicians were able to see where new roads had been built and existing roads had been widened or rerouted. They made the positional corrections for the street centerlines on the display screen.
      For the 911 coverage to be complete, the street centerline map also had to contain the locations of all alleys in the city. Unfortunately, only about half the alleys were marked on the right-of-way maps. Locations of other alleys existed only on paper maps. Rather than incur the expense of scanning these maps, ESD measured the dimensions and distances of the alleys from nearest street and then wrote an MGE algorithm to place the alleys in the centerline map.
      An important data layer in the GIS and 911 system will be building footprints and address information. Adding this data to the Unimap was the responsibility of the Whitney Young students. ESD scanned existing city structure maps which contained the building footprint information. The student then used a heads-up map display at ESD's office to overlay the structure map with the GIS map.
      The vectorization process was time consuming, but relatively uncomplicated because of automation. A total of 950,000 building footprints were digitized. To place a building footprint on the GIS map, the students used a mouse to click on the building location on the scanned structure map. A program automatically created vectors representing the building walls and placed them on the GIS. Street names, addresses and building height information also were added in similar fashion to the map as vector data.
      The students digitized about 40 percent of the buildings. The remainder of the vectorization was completed by Coherent Research Inc. After the digitization was completed, the students referred to hard copies of aerial photographs taken in 1994 to ensure that new buildings and expansions were correctly represented on the map. This phase of the project was being wrapped up in May 1995 as the students prepared for graduation.

Emergency 911
Chicago residents may not witness first hand the savings in tax dollars that results from the GIS, but many will benefit from enhanced 911 service. The city has developed a computer-aided emergency dispatch system and automated map display that uses information from the GIS Unimap. Beginning in the fall of 1995 when the 911 system goes on line, all emergency calls will be routed through a new operations center at the west end of Chicago's Loop.
      Incoming 911 calls will be connected within 1.2 seconds - the fastest in the United States, said Bill Corbett, the 911 Project Team Coordinator. When the call is received by a call taker in the operations room, caller-ID will trace it to its origination. The caller's address location and other relevant data will pop up on a display screen. If the caller is on a cellular phone, they can provide the call taker with an address or name of a well-known landmark to trigger the system.
      This summer, Chicago will mail out millions of survey forms for citizens to use in notifying the 911 center of any medical conditions, disabilities or foreign language needs at their location. As these surveys are mailed back, the data will be input into the 911 database. Once caller-ID determines the call location, the computer-aided dispatch system pulls up the appropriate information file from the database and displays it on the call taker's screen. Based on medical information in the file, dispatchers will make a more thorough assessment of what emergency equipment is required at the site.
      Planning Research Corp. of McLean, Va., developed the computer- aided dispatch system that Chicago has installed in its 911 operations room.
      Pinpointing the caller's location also triggers a search of an automated map display system (AMDS) called StarView, developed by Trimble Navigation Ltd. of Sunnyvale, Calif. The AMDS is a real-time map display that integrates data from the computer-aided dispatch, 911 GIS database and automated vehicle location (AVL) system. It displays a digitized map of the emergency location and also shows the locations of all emergency vehicles in the area.
      This map includes the centerline and building information from the Unimap. A geofile within the automated map display translates GIS map database elements, such as addresses and building heights, and displays them on the screen. Other layers of data from the city GIS can be shown on the map display as needed. The call taker can zoom in and out to view small map details or general neighborhood layout.
      The map and its attribute information become critical when a call originates from a location other than where the actual emergency is occurring. For instance, a caller notifies 911 that a house on the next street is on fire but doesn't know the address. The caller can describe the location, which the call taker will find on the map, or the call taker can query the caller, asking if the fire is at the three story or two story house on that street. All that GIS information will be at the fingertips of the call taker on the AMDS.
      The call taker then decides to route the call to a police dispatcher or a fire/medical dispatcher, who are all sitting in the same room. These dispatchers also have similar display screens. As the dispatcher begins querying the caller on the specifics of the emergency, the AVL is then used to identify the closest available emergency vehicle.
      The AVL is a GPS-based system developed by Trimble that uses in-vehicle GPS receivers to determine the location, heading and velocity of 360 fire trucks and ambulances throughout the city. This information is collected at mobile data terminals in each vehicle and sent continuously by radio back to the operations room. Each vehicle's location and status is available for viewing at all call taker, dispatcher and supervisor stations in real time.
      The in-vehicle GPS receivers are capable of dead reckoning, which means they continue to determine locations even when Chicago's tall buildings temporarily block the GPS signal from the satellite.
      When the emergency is located, the incident location is automatically centered on their map display. The dispatcher is able to zoom in or out to see the nearest emergency vehicle and status. The system also has the ability to make recommendations as to which vehicle should be assigned the call based upon availability and proximity. In cases of medical emergencies, a computerized flip chart allows the dispatcher to talk the caller through possible medical procedures that may save a victim's life while the emergency units are enroute.
      The 911 office has installed a dedicated fiber optic cable linking it to 100 engine companies, 59 ladder companies, 58 ambulance stations, 25 police barracks, and every other city departments. For the time being the dedicated line will only be used to transmit 911 data, but eventually may be used to network the entire GIS.
      When the dispatcher chooses which station or unit to route the call to, the address, medical and other information is transmitted in text form via the fiber optics and printed in text format at the station. A few fire and police command vehicles have in-vehicle GIS displays to receive the map information as well.
      911 has also installed an FM radio data transmission system to transmit information to units out on call. Because they are away from the station, they are not directly attached to the fiber optic cable and must be reached by radio. Each vehicle is equipped with a mobile data terminal that allows it to receive the same text information by radio that goes to the stations via fiber optics. The mobile data terminal also allows the emergency crew to request backups or send information about the emergency back to the operations center.
      This information lets the operations center assist in managing the emergency. Information fed back from the field also becomes part of the permanent record for that address location. The next time a call is received from that information, the emergency crew may be able to use the historical information.

Managing the Data
Chicago is building its GIS and 911 system with a combination of Intergraph and ESRI products. Intergraph MGE has been used extensively in the city for planning and design projects and will continue to be used for those applications. ARC/Info and ARCView will be used for many data analysis and display functions.
      Attribute data related to the Unimap is stored in a DB2 database. The city uses an Oracle database to run its MGE functions and has obtained a gateway to access DB2 data for use in MGE. Trimble also developed a set of GIS tools that converts the MGE data from the Unimap into the StarView compatible format for use in creating the GIS database and for subsequent use in the CAD geofile. This tool will be used by the Chicago GIS engineering staff to update and maintain the 911 GIS database.

About the Author:
Kevin Corbley is the principal in Corbley Communications, specializing in PR and marketing for remote sensing, GIS and GPS firms. He is located in Denver and may be reached at 303-987-3979.

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