County GIS project hits the road
When Garrett County, Md., engineers needed to review infrastructure maps, they had to sift through one continuous printout of state highway bridge inspection reports and road inventories. Not only was the map unwieldy, it contained outdated information. All that changed, however, when County Project Engineer Dwight Emory found a way to develop a centerline map and automate access to infrastructure inventory.
Assisted by Transmap, a Columbus, Ohio-based GIS developer, the county started building its files in 1998 with digital photographs. Engineers mounted digital cameras on a van, which allowed for accurate picture-taking while traveling up to 45 miles per hour. The digital color images were taken every 35 to 50 feet as the van traveled both sides of every county road. Air compressors continually cleaned the camera lenses, allowing for image collection in almost any type of weather.
An inertial navigation system collected distance, direction and right-of-way data to complete the road network map. The images with GPS information were placed on a CD for formatting and editing. Centerline points were inserted along with identification such as traffic signs, signals and guardrails. Finally, the points were integrated into a GIS database.
Today, with the click of a mouse, Emory and his staff can access centerline files and color digital images of the county’s 700 miles of roadway in 30- to 50-foot sections. The images are linked to associated data such as maintenance records and state bridge inspection reports. Even accidents are included, thanks to daily electronic police reports. Emory expects savings in time and money to increase as the GIS is fine-tuned and employees become more knowledgeable about it. “We refer to the visuals every day,” he says. “But we’re being over-cautious now by verifying many visuals with field visits. That will decrease as we become more comfortable relying on the images.”
Project planning and information gathering is getting easier as a result of the new system, he adds. Last fall, for example, Emory used the system to specify road length and line-striping patterns for a maintenance project. He also uses the system to resolve complaints from residents and prints digital images of roads in question for review by county commissioners.
Emory says the network is most useful because it offers accessibility to all department employees. “The more people who use it, the greater our savings,” he says. Eventually, he wants to provide a terminal that county residents, businesses and organizations can access as well.