Charting the Roads of the Vast Navajo Nation

Using GIS to Assess and Manage Tribal Transportation Infrastructure


  • The Navajo Roadway Inventory System offers the first consistent, verified interpretations of Indian Reservation Roads regulations.
  • The Navajo DOT selected a turnkey server offer from Esri preloaded with ArcGIS for Server.
  • The team mapped more than 70,000 miles of roads and trails.

Spanning approximately 27,000 square miles across three states, the Navajo Nation is the largest sovereign nation in the contiguous United States. It has a strong presence in US government and often leads the way in tribal efforts to promote key areas such as economic development, health care, and education at the national level. Despite its prominence, the sheer size and remote nature of the Navajo Reservation presents unique challenges in managing its infrastructure and resources.

photo of a remote road
photo of roadwork in progress

The sheer size and remote nature of the Navajo Reservation presents unique challenges in managing its infrastructure and resources.

Consider, for instance, the road inventory that tribes submit each year to the Indian Reservation Roads (IRR) program. The IRR program maintains the official inventory of reservation roads in the United States and is designed to allocate federal funding to tribal governments for transportation planning and road maintenance activities.

A component of the broader Integrated Transportation Information Management System program, the Bureau of Indian Affairs (BIA) Division of Transportation maintains the national reservation road inventory in a system called the Road Information Field Data System (RIFDS). Each year, as part of the IRR program, tribes are eligible to submit their road inventory data to one of the 12 BIA regional offices. There are approximately 560 nationally recognized tribes that fall under the 12 BIA regions. The Navajo Nation submits its road inventory to the BIA Navajo Regional Office (BIA-NRO) in Gallup, New Mexico.

The Navajo road inventory was far from comprehensive. In early 2006, its official RIFDS inventory contained approximately 9,800 miles of roads. Roughly 6,000 miles were BIA roads, and the remaining 3,800 were primarily state and county roads, with very few tribal roads mixed in. Navajo transportation officials determined that the road inventory was substantially underperforming in two key areas:

The selected route is highlighted in red and labeled with a corresponding section number.

The selected route is highlighted in red and labeled with a corresponding section number, and then the map is automatically generated.

To address these issues, in April 2006, the Navajo Division of Transportation (DOT) launched a proactive and aggressive campaign that would expand its internal capacities, establish a systematic method for identifying eligible public tribal reservation roads, remove subjectivity from regulations, and build a system to improve both the quantity and quality of the road inventory data. With the support of the Navajo Nation Transportation and Community Development Committee and under the direction of former Navajo Division of Transportation director Tom Platero, the Navajo Inventory Team and consulting project manager Nick Hutton embarked on an innovative and challenging endeavor that would span more than four years.

The first step was to fortify the Navajo DOT's existing technology infrastructure. New enterprise-class servers were put into place, network bandwidth was expanded, and new data was collected.

To save time on installation and testing, the Navajo DOT selected a turnkey server offer from Esri preloaded with ArcGIS for Server and Microsoft SQL Server and preconfigured to optimize system performance. This allowed the Navajo Inventory Team to focus on developing core programs and data instead of tweaking the new system. The result was a spatially enabled, multitiered, web-based information architecture supported by an integrated hardware and software solution and powered by Esri technology.

The next step was to obtain and develop the required data. The Inventory Team was able to acquire brand-new, reservation-wide aerial photography captured as part of a joint project between the Department of Interior and the State of New Mexico. Once the imagery was loaded onto the new system, it was time to start digitizing road centerlines.

Digitization was carried out by a team of GIS technicians with the help of Esri Partner Data Transfer Solutions (DTS) of Orlando, Florida, which was selected to facilitate the process. It wasn't until this time that the team realized the full extent of the project. After several months of heads-up digitizing, the team had mapped more than 70,000 miles of roads and trails. While not all the digitized centerlines were eligible for the official IRR inventory, the potential challenges associated with managing these roads were daunting to DOT officials. This realization underscored the notion that automation would be an absolute necessity in the development of the Navajo DOT road inventory system. While the GIS techs continued the digitization process, the programming staff at DTS and the Navajo DOT Inventory Team were busy developing the inventory management system.

The team concluded that the system must be secure; web based; geospatially enabled; usable by staff members both with and without GIS expertise; and capable of mapping automation—specifically, strip map automation. In addition, the team identified the need for a robust querying component that included bidirectional filtering between the map interface and the filtering page.

NAVRIS bidirectional filtering of data between the map interface and the filtering page.

NAVRIS bidirectional filtering of data between the map interface and the filtering page.

What emerged was a system the Navajo DOT calls the Navajo Roadway Inventory System (NAVRIS). In addition to web, GIS, and automation capabilities, NAVRIS incorporates a series of validation scripts to ensure that the data is entered in accordance with program requirements.

One of the most challenging aspects of the project was establishing consistent interpretations of the IRR program regulations between the BIA-NRO and the Navajo DOT staff. This took many months of research in collaboration with BIA-NRO chief engineer Harold Riley and his staff. To the credit of both agencies, considerable common ground was established, and the findings were subsequently programmed into the core automation and validation logic of NAVRIS. As a result, the percentage of roads questioned by the BIA because of missing or incorrect data has declined dramatically.

As of the 2010 IRR submission cycle, the Navajo DOT has significantly increased the number of miles in its inventory. It grew from 9,800 miles in 2006 to nearly 16,000 miles, including approximately 6,000 miles of tribal roads. The additional mileage and updates to the existing data increased the Navajo Nation's IRR funding by an average of 30 percent compared to its 2006 funding level. To date, the Navajo region has received a fifteenfold return on the Navajo DOT's initial investment in the IRR project. This adjusted allocation will allow critical transportation infrastructure improvements, supporting access to education, employment, health care, and other services for the nation's widespread residents.

In addition to the development of the NAVRIS system, the Navajo DOT Inventory Team established a series of programmatic policies and standards to supplement the technology. Due to the rural nature of the reservation, determining the public eligibility of tribal roads has been a historically difficult process. In an effort to establish consistency in properly identifying a public tribal road, the Navajo DOT developed a public roads identification guideline that provides a checklist of characteristics that a road must contain before it can be considered public.

Today, the Navajo DOT continues to develop NAVRIS as part of its ongoing IT strategy. NAVRIS offers the first consistent, verified interpretations of IRR regulations and the ability to programmatically generate the required BIA deliverables. By taking the initiative to build a geospatial road inventory program that helps define and facilitate the IRR process, the Navajo Division of Transportation has become a stronger, more sophisticated tribal entity with more time and resources to support the development and maintenance of its expansive infrastructure.

For more information, contact Jonah Begay, Navajo Division of Transportation GIS supervisor (e-mail:, or, at Data Transfer Solutions, LLC, Nick Hutton, director of asset management (e-mail:, or Allen Ibaugh, president (e-mail:

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