How geospatial data can improve US elections

July 18, 2018  - By

A voter enters a polling place. (Image:

With the mid-term elections coming ever nearer, states are turning to geographic information systems (GIS) to help manage them.

Digital geographic representation of precinct boundaries within a GIS allow for transparency and ease of use for voters, candidates and electoral management, according to the National States Geographic Information Council (NSGIC).

GIS also enables the optimal siting of polling places for both voter access and the cost efficiency of operating polls.

Finally, GIS provides a platform for automated quality-control processes that ensure accurate voter precinct assignments.

“An electoral system with integrity — enhanced by accurate, authoritative geographic data and presented clearly and transparently — has never been more important,” said NSGIC President Andy Rowan.

Why GIS is an improvement over address files

NSGIC’s Geo-Enabled Elections project brings together geographic information systems (GIS) leaders in state government, local elections officials and state elections offices, national GIS and elections organizations, and federal partners to identify opportunities to integrate GIS into elections systems across the country.

The overall goal is to strengthen elections management and citizen engagement. The project aims to provide the impetus for replacing non-spatial “address file” tables with the visual and analytical advantages of election precinct and voter data in a natively GIS format.

Geo-enabled elections overcome the four fundamental challenges with the existing address list approach to precinct management, according to Rowan.

In the address list approach, Rowan said,

  • No actual boundaries are stored explicitly in the systems,
  • Quality control is difficult without a method to visualize precinct assignment using aerial photography and boundary information that can change frequently,
  • There is no efficient method for applying large-scale precinct boundary updates, and
  • The process is usually not aligned efficiently with other state and local address or boundary-management processes.

To this end, the project conducted a nationwide survey on elections data in the first half of this year. More than two-thirds of states responded.

Here are key takeaways from the baseline survey.


The survey found that 55 percent of responding states confirm voter registration addresses against a database of known addresses such as a driver’s license or state ID database, a statewide point address set, a master address database used for 911 call routing, or a commercially available address database.

“The results indicate a need to advocate for coordination between state agencies (such as the state elections department and the department of motor vehicles) and encourage integration of the voting system and other systems,” said Jamie Chesser, the Geo-Enabled Elections project manager.

Election Precincts

More than half of responding states indicated they maintain statewide mapping of precincts. Within this group, 40 percent also maintain a layer of sub-precincts in digital mapping systems.

“There remains a need to develop local precinct data content and procedural standards to examine the relationship between precincts, local and state boundaries, and residential structures,” Chesser said.

Other Data

In all, 82 percent of states keep up-to-date spatial data of city and county boundaries, which is essential for computer-based mapping of precincts.

“Statewide spatial data — especially city, county, school, and special district boundaries – are essential to mapping precinct boundaries across the state,” Chesser said. “The survey reflected, however, that accuracy of current city and county boundary mapping varies

A substantial majority, 79 percent of respondents, confirm their mapping of state-level district-based elected offices are accessible online in a digital mapping format.

Survey responses were coordinated by state government representatives who focus on the development and deployment of mapping data and systems across state agencies and local governments.

Later this year, NSGIC will release the results of a study probing the spatial approach to elections management from the perspective of state elections officials.

The two-year Geo-Enabled Elections project, underwritten by the bipartisan Democracy Fund Voice, convenes a wide variety of stakeholders to explore ways geographic information systems and related processes can enhance elections management and citizen engagement across the U.S.

Download the full report here.

2 Comments on "How geospatial data can improve US elections"

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  1. Chris Stohr says:

    Can these articles be formatted for printing. Some of us share printed articles with interested parties who are not social media users. Thanks, Chris

  2. Ask Jugadu says:

    Thank you for sharing this useful article.