case study
GIS Allows Colorado Department of Transportation to Capture the Full Value of Their Properties
Property Values
Bringing right-of-way data into a GIS environment is enabling the Colorado Department of Transportation (CDOT) to maximize the performance and potential of its real estate assets.
A key advantage of geographic information system (GIS) technology is how it allows spatial and related data to be gathered, secured, and made accessible to a wide number of users. GIS services enable many disparate stakeholders to not only edit and maintain information but also to provide access to support a wide range of business-specific applications.
CDOT's effort to move right-of-way (ROW) and real property information from its historical place in the filing cabinet and into a GIS database environment is a case in point.
Now, with just a simple query, CDOT's GIS team is able to provide both internal and external customers with accurate information on DOT owned and managed land and easements. Previously, such an effort might have required days or even weeks of searching, or else the results would have been little more than educated guesswork.
CDOT is now also increasingly able to see the true extents of its individual property assets and to determine how best to maximize and monetize these—whether by selling off excess parcels or by installing solar power generation in the right-of-way, both of which generate revenue for the department.
Data Gathering
The ROW effort at CDOT started in 2012, initially not so much for parcel data, but rather as the GIS team began to understand how to use CAD-to-GIS interoperability tools to move data from Bentley to its Esri-based GIS. It was not long before the GIS staff recognized that the ability to move data from CAD to a GIS could prove useful for converting all the paper and CAD records to a GIS, as Nick Mesenbrink, a GIS specialist with CDOT, explains.
At about the same time, CDOT's Headquarters ROW office, which had previously relied on the five regional offices for parcel and right-of-way information, began to investigate the possibility of having a centralized spatial database of the DOT's right-of-way.
These two efforts converged a couple of years later when CDOT brought on an external consultant (Applied Geographics) to help catalog, inventory, and convert the source plans and documents associated with the DOT's right-of-way.
The work done by Applied Geographics to help set up the ROW GIS database took five years and finished in March 2020. It represents a multi-million-dollar investment for CDOT. A strategic approach was taken to prioritize the ROW source documents, in the sense that the most recent (and, therefore, likely the most accurate and complete) were cataloged and incorporated first. CDOT's GIS team took a driving role in the conversion effort, which essentially set out to catalog "whatever we could find," according to Mesenbrink. That included delving deep into the regional offices' archives, as well as into new projects that included ROW-related information.
Two methods were then used to process the found data: the first involved converting DGN files where available, and the CAD-to-GIS tool was used to convert existing MicroStation files to GIS.
The second and more labor-intensive method involved georeferencing and digitizing PDF files of right-of-way plans and as-builts and creating GIS records from that data.
The first method was responsible for producing roughly 20 percent of the records, while the more manual process accounted for about 80 percent of the total effort. Together, they were able to account for over 80% percent of the state's highways having GIS-based ROW information apportioned to the ROW database—rights-of-way boundaries, land parcels (including general ledger information apart from the highways), easements (both slope and permanent), and so on. The remaining 20% consists of either incomplete or missing source files, but the GIS platform includes a layer that shows where these areas are. These gaps are marked for future research by the team.
Life Cycles and Standards
The next stage was to start developing a life cycle for the continued maintenance of the data.
"Applied Geographics did a great job, but they were only able to capture what we gave them," Mesenbrink explains. "If they were only able to find a 1950s plan, then that's what they processed. If something came up that had happened in 1990 but a record couldn't be found, then the 1950s version remained the current one."
Recognizing the data currency issues, the GIS team is working with CDOT's Headquarters ROW group and Property Management teams to develop processes for data maintenance to ensure that the data is continuously maintained, and CDOT recently hired an intern to carry out the QA/QC work. This work includes checking the GIS database against county parcel records.
"We're lucky that in Colorado the Governor's Office of IT has been compiling statewide parcel GIS data. We can compare our data with that for all of the counties," Mesenbrink continues.
"CDOT's Property Management team, which operates separately from the Headquarters Right-of-Way group and from the GIS team, is interested in using the parcel data as their official parcel catalog," he says. "Right now, they're using Excel. We're really invested in getting the parcel data up to speed so that they can use it in real time. Getting that intern will really help."
Standards are an inevitable requirement, and another preoccupation for Mesenbrink has been building the documentation on how everything works—the metadata.
"We want to be really transparent about this data," he says, "and following feedback from the Property Management team, we're currently right in the middle of revising the data schema to enhance the usability of the data. The Property Management team is also going to be making an additional full-time hire to handle GIS data. That'll significantly increase our capacity to handle data updates and maintenance going forward."
Visibility and Dashboards
Colorado has been a leader in the development and use of dashboards, gaining praise (and awards) for its efforts from the National Association of State Chief Information Officers (NASCIO).
CDOT's GeoHub is powered by ArcGIS Hub that enables staff to develop, share, and use geospatial applications, web maps, and data. Built on Esri's ArcGIS Enterprise portal, it is a NASCIO award winner and provides users with information on traffic operations, wildfire situational awareness, freight and trucking, avalanches, Americans with Disabilities Act (ADA)-compliant curb ramp accessibility, operations readiness, and buildings assessment condition, among other applications. The Real Property Data Viewer, the app that provides ROW information to the rest of CDOT, was originally created in ArcGIS Online and will be transitioned to ArcGIS Hub in early 2022.
Even before that happens, the GIS team is already making the ROW data accessible and transparent. There is logic to this because as a multi-million-dollar project, which needed State Transportation Commission approval, visibility of the data is highly important.
"For example," Mesenbrink explains, "we've looked to give the Property Management team the ability to see their data in real time, including how many excess and remainder parcels it has and how many leases they have in a given county, as well as other information by grouping.
"It's important to understand that this isn't survey-grade data. It's planning and mapping grade. The intention of the Real Property viewer is to get people to the authoritative data, to be a pointer to the as‑built plans, deeds, leases, and so on. Previously, there was no one place that you could access that, but CDOT's ultimate aim is to have all data in one place.
"I don't see our ROW data going to any greater resolution—10 to 20 ft. is fine for planning purposes. That still allows the CDOT teams, including Property Management, to do some pretty cool things, though—and perform some very interesting analyses.
"We've been working with our Electric Vehicle Planning group to look at charging station placement, at solar power generation on rights-of-way, and with other state agencies to look at low overhead dam analysis, land and water conservation, parcel cleanup and water quality . . . and a big one, one which originally got a lot of attention from the Transportation Commission, is selling off properties that are no longer needed and raising additional funding. Another example is helping our Roadway Data Management team to be more proactive about infrastructure improvements, capturing the information to update their HPMS (Highway Performance Monitoring System) data. That's important from a federal reporting and annual funding perspective."
Game Changer
"We couldn't do any of this before because we didn't have the GIS representations," continues Mesenbrink. "Our precursor was centerline representations with links to the right-of-way plans. You couldn't see widths or anything like that. You couldn't do anything beyond [seeing] how many rights-of-way existed along a given highway. Now, we can do full spatial analyses. This data just allows people to see things they have never seen before.
"Intra-agency and interagency cooperation is already much improved, and eventually all of the data is expected to be public facing once we are satisfied with the quality and currency. The GIS team, the Headquarters Right-of-Way group the Region Right-of-Way offices, the Survey Coordinator, and the Property Management team are all dedicated to seeing this project through and maintaining this data for the agency. “Mesenbrink says, the data also holds the promise of being able to bring certain types of analyses—water quality and drainage, for example—in-house, which previously had been performed by a contractor.
"Rights-of-way provide a baseline for so much, and I'm surprised how few other DOTs have something like this. We're still discovering new use cases for the data, and as more assets come online in GIS, you're just able to do more and more. The sky really is the limit, and typically once a month we're having someone come to us asking about a new application of the ROW data. A year up the road, we'll hopefully have additional apps and interesting use cases that we've not yet even thought of."