System assists village with asset management

Last year, Arlington Heights, Ill., a densely populated suburb of Chicago, collected digital images of all its roads and right-of-way assets to help build its GIS. Using the photographs, the village plotted the locations of thousands of public assets and has begun evaluating their conditions.

Using orthophotos from Cook County, Arlington Heights began creating its GIS by digitizing topographic data such as building footprints and road edges. Next, it needed to add data about the locations of assets — such as trees, signs and utility poles — in the rights-of-way and to verify road edges and centerlines.

Village staff considered using traditional surveying techniques to gather the information but found that it would be costly and time-consuming. The village opted instead to contract with Columbus, Ohio-based Transmap to collect stereoscopic images of roadway features.

The company collected the images from vans equipped with digital cameras, a Global Positioning System (GPS) receiver and an inertial navigation system. The cameras (two mounted to the front and two mounted to the sides of each van) took pictures every 30 feet.

In spring 2001, the company’s mapping vans drove all of the village’s 268 street miles, recording every asset in the rights-of-way. Field engineers took digital images of street signs, culverts, road edges, sidewalks and other infrastructure, including more than 45,000 trees that lined the streets. In 10 days, the company had gathered comprehensive data on the village’s assets and had created a road network map, adding mileposts to the centerlines to create a linear reference system.

After it collected all the data, the company extracted information, such as location and description, of the features inventoried. By August, the company had added the data to the village’s GIS.

The company loaded the digital images captured by the vans onto the village’s GIS server so all departments could access them through a standard Internet browser. Users can view an image by clicking on its location on a map or by typing in a street name, route ID, address, intersection or milepost.

With access to the updated GIS, departments do not have to dispatch workers to physically survey the conditions of assets such as signs, traffic lights and curbs. Instead, staff members can click on the images and record the information they need. The village has used the images to create a basemap of road centerlines, to inventory bridges and traffic signs, and to collect information about the condition and location of assets.

Arlington Heights has been using the data to work toward GASB 34 compliance. The city’s Fire Department has used the data to evaluate the condition of fire hydrants; the Engineering Department has used the system to evaluate traffic signs and signals; and the Public Works Department has used the data to evaluate the condition of manholes, sidewalks and driveways.

The village plans to update its GIS with new images periodically. “The images are geocoded with GPS receivers, so they can be used for historical reference,” says Janusz Kwiatkowski, GIS coordinator. “They show what the village looked like at the specific time you took your pictures. This means that you can use them to show how the place has changed over time. With updates to the data every couple of years, you can determine what areas have developed most and target maintenance demands for specific areas.”