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Digital Maps Assist Emergency Responders

Map application works on mobile devices without a network connection, helping responders in areas of Frederick County, Va., without cellular service.

A digital map application has revolutionized the way emergency responders are finding locations in rural areas of Frederick County, Va. The county’s IT department and GIS division created a mobile map book that operates on smartphones and tablets without using an Internet connection, giving personnel a more reliable look at surrounding areas.

Responders can type in an address, and the program will automatically flip to the appropriate map, giving additional details such as the locations of fire hydrants and boundaries. Launched in May, the mobile map book replaces the paper-based map books that county fire departments had been using for years.

Patrick Fly, GIS manager for Frederick County, said his team was asked to update the paper maps last year. While some initial efforts on the project were made, a staff member suggested upgrading to a digital format. Fly ran the numbers, discovering that not only would a digital map book be cheaper to produce, but it would also be easier to update.

Built entirely in-house, the county took advantage of software it already owned, including Esri ArcGIS for Desktop, Sublime Text and Adobe Dreamweaver. The only cost was staff time.

The app is roughly 400 MB in size and includes 500 images. But unlike other mapping programs, the county’s mobile map book doesn’t connect to the Web or a server to work: It’s entirely self-contained on a person’s mobile device.

“One of the issues we have is we don’t have guaranteed cellular service throughout the county,” Fly said. “So part of the goal of this project was to allow it to be used on a mobile device, but at the same time understanding there might not be cellular service to access it. We had to keep it small, but have all the data built into it.”

Jeremy Coulson, webmaster in the county’s IT department, said the biggest challenge was finding a way to make the data available on a device that would run natively inside a Web browser. He took comma-separated values (CSV) files — files that store numbers and characters in plain text — from the GIS team, and turned those files into JavaScript Arrays and HTML tables.

Whenever an update to the map is made, users simply access a zip file on the county’s website and download the new application.

“A lot of the stuff in the map book would have been a pretty simple Web application with a browser and a server,” Coulson said. “But because it needed to be completely platform agnostic, we couldn’t rely on server technology. It had to work all in a Web browser.”

County GIS Analyst Lindsay Felton was responsible for the app’s planning and development. She said the basic framework took about a month to develop. Just like a paper map book, the program still has pages, but in digital form.

The mobile map book contains maps and aerials of Frederick County subdivided into two different grids — one is an overview of the county, and the other contains a more detailed look at urban and densely populated areas.

Looking Ahead

Users have chimed in about the app and changes they’d like to see in the future. According to Coulson, the biggest request has been for driving directions to the addresses entered into the program. The problem is that doing so would require network access, which isn’t reliable in all areas.

The mobile map book team has been experimenting with a way to make the driving directions feature available only when a network connection is detected by the responder’s device.

Currently, the mobile map book is only available to emergency and first responders in Frederick County. But Fly said he’d like to make the application available to the public in the future. But opening up the program means an increased load of support requests, which could be overwhelming.

“We’re a relatively small shop and don’t necessarily have staffing to deal with calls to support this on all the different devices out there,” Fly said. “So we’re trying to figure it out.”


Miriam Jones is a former chief copy editor of Government Technology, Governing, Public CIO and Emergency Management magazines.