High-Tech Road Repair

In April 2007, a gasoline tanker crashed and burned while negotiating the MacArthur Maze, a network of interstate connections around the San Francisco/Oakland Bay Bridge in California. The resulting blaze was so intense that it caused parts of the I-580 overpass to crash onto the interstate below.

Documenting an overpass failure
CHALLENGE: Documenting an overpass failure

What do you do when you need to document the scene to understand what happened and why? How do you collect data in a situation like this, with contractors rushing to demolish the overpass? The California Highway Patrol's Multidisciplinary Accident Investigation team (MAIT) opted to use a 3D laser scanner to collect forensic accident data. Using the ScanStation from Leica Geosystems, MAIT scanned the scene from the ground to the top of the destroyed overpass in a few hours. According to Lt. Dave Fox, the MAIT team manager, "The ScanStation enabled us to be very mobile and efficient while collecting very detailed data. Typically we can acquire 500–1000 points; with Leica's 3D laser we collected millions. We couldn't have collected that kind of information without laser scanning." Not only that, but the laser let the team collect data from a safe distance and gather data from many angles. The detailed forensic data MAIT gathered will allow Caltrans, California's Dept. of Transportation, to analyze and reconstruct the overpass failure. The overpass reopened less than one month later.

Contact Tony Grissim, Leica Geosystems Inc., Norcross, GA; 831-643-2972, [email protected].