McHenry County, Illinois Division of Transportation
If ever there was a case-in-point example of location at work, the McHenry County Division of Transportation (MCDOT), located in northeastern Illinois, is it. Using Cartegraph and ArcGIS together, the agency accounts for a diverse inventory of assets that includes pavement segments, signs, bridges, traffic signals, guardrails, and more. In all, the MCDOT boasts 11 distinct Cartegraph databases, each one connected with its corresponding geographic information system (GIS) feature class.
One of the agency’s most comprehensive databases is dedicated to its drainage network. Locating and cataloguing more than 9,000 individual components that comprise the network was meticulous work. But the time spent was made worthwhile by the highly detailed records the agency was able to create using Cartegraph and GIS in combination.
“In GIS, you typically have one shape on the map that matches up with one record in the database,” said Shannon Dolte, MCDOT’s GIS Specialist. “Whereas, in Cartegraph, each record can have numerous subordinate records to address improvements, inspections, attachments, or whatever the case might be. That’s where Cartegraph adds a new dimension to our GIS. It’s the child record sets that expand the functionality beyond what’s typically available in a stand-alone GIS.”
Though McHenry County DOT had been using Cartegraph and ArcGIS in its daily operation for some time, the agency was using the systems independent of one another. This situation was especially evident in the case of its drainage network. “At the time, what inspection and condition data we had was being housed in the GIS database,” said Dolte. “Fundamentally, we didn’t believe that this data should be recorded there. We knew that Cartegraph was more appropriate to handle this type of information.”
On the Cartegraph side, the record sets that did exist either had no location information or were paired with sketches depicting asset locations. “In GIS, the accuracy of location is relative to the context in which it is viewed,” said Dolte. “For instance, if you have an aerial photograph that’s a decade or two old, you can’t zoom in very tight because the view becomes too pixilated. So, a lot of times, things were just roughed in with less than ideal accuracy.”
Assessing the situation, Dolte and the MCDOT team realized that the effectiveness of both systems would be maximized by integrating the two together.
With Mr. Dolte as the project lead, MCDOT integrated Cartegraph with its existing ArcGIS geodatabase. Prior to the integration, Dolte reviewed “GIS Integration," a Cartegraph publication intended to assist with the integration procedure. And during the process itself, he consulted the Cartegraph Support team. This careful approach resulted in a well-executed integration and avoided many potential issues.
Using the systems together, Dolte developed a drainage database featuring a level of detail that wasn’t possible using GIS alone. The integration of the two systems allowed him to take information housed in GIS, such as construction dates, attachments and condition, and transfer that data to Cartegraph. Then, using Cartegraph’s “Multi-Edit” function, he was able to add new inspection and attachment child records for each parent record — a process that was far easier than using GIS on its own.
“The multi-edit feature allows you to change several fields simultaneously,” said Mr. Dolte. “With GIS you have to update each field individually. Additionally, Cartegraph allows you to attach numerous supplemental files to a single record. Whereas, only one field within a GIS table is permitted to support a hyperlink to another file.”
To enhance the integrated drainage database, Dolte took advantage of Cartegraph’s built-in Type Library, a feature that allows users to choose one value within the library, and all associated information as well. To further expand the library, Dolte downloaded all pertinent Illinois Department of Transportation (IDOT) construction detail drawings for each type of drainage structure in the network. Dolte then saved each digital image in the type libraries located within Cartegraph’s Project Home. This comprehensive approach resulted in customized libraries containing standardized visual references for every conceivable structure within the system.
With the drainage structure libraries established, Dolte then created his own CAD2GIS conversion process. Using the libraries as a reference and computer aided drafting (CAD) files as the backdrop, he verified the flow direction, connectivity, and other physical characteristics of each pipe and drainage structure, drew those features in GIS, and then transferred each selection over to Cartegraph. “Now when you chose a particular feature, such as catch basin, you can open up that library and see an image of the construction detail specific to that structure.”
Today, McHenry County DOT’s Cartegraph drainage database contains more than 9,000 individual records, 9,024 to be exact; all integrated with as many geoconnected fields as reasonably possible. Because of this integration, McHenry County DOT personnel can view drainage system information in the context of an Esri basemap and also explore more detailed information in the Cartegraph database. Dolte admits that getting the required information in place took considerable patience and effort, but the hard work has set the stage for what he sees as a long-term, proactive solution for drainage system management and maintenance.
“When I talk to others about Cartegraph, I describe it as a tool for expanding the capabilities of GIS,” said Mr. Dolte. “The ability to attach multiple records to one record in your geodatabase — for improvements, for photo documentation, for inspections…or whatever — provides a new dimension to your GIS. GIS is great at recording locations and Cartegraph is just as good at storing information. However, the best solution is an integrated approach that capitalizes on the strengths of each system.”