KS Associates Inc., a civil engineering and surveying firm located in Elyria, Ohio, is under contract with Ohio DOT District 12 to provide design services to replace the decks of three mainline bridges on busy IR-90.

The firm has completed topographic surveying for the Interstate 90 project to gather details of existing conditions for use throughout design. The survey was performed using a combination of 3D laser scanning and mobile terrestrial LiDAR. The approach helped the firm capture large amounts of data, reduce site visits, minimize the impact on traffic, and maximize safety for surveyors and motorists.

“Surveying bridges always presents unique challenges,” says Mark Yeager, director of surveying services at KS Associates. “The detail needed is often located in difficult-to-access areas with heavy traffic, as was the case for this project. The IR-90 bridges carry eight to nine lanes of high-capacity urban traffic, so performing surveying work safely, minimizing traffic delays and completing the project according to a rigid schedule were critical success factors.”

Another surveying challenging was to capture information that the design team will need throughout the design process without multiple site visits. This is especially critical for a high-speed freeway. KS utilized a static scanner to capture details of the bridges’ superstructures and deck surfaces. The scanner was particularly effective in checking bridge clearances and capturing information on as many as 18 beams at each bridge.

The team then used mobile terrestrial LiDAR to acquire pavement, sign and guardrail locations. A scanner secured to a vehicle driven at highway speeds captured detail for more than 19,000 feet of freeway and 12,000 feet of ramps and side streets. Mobile LiDAR data also eliminated the need for lane closures and improved safety by reducing the amount of time needed to survey the area.

About KS Associates Inc.

KS Associates Inc. is a civil engineering and land surveying firm founded in 1987. The firm provides planning, design, bidding and construction phase services related to public infrastructure projects in the areas of transportation, potable water, waste water and storm water. The firm also offers site development engineering services, coastal engineering services, land surveying and mapping services, and 3D laser scanning services.