Crash Investigators Find the Intersection of Speed and Accuracy with GNSS Solutions

Quick clearance of all traffic incidents—from disabled vehicles to fatal crashes—is important not only for mobility but also for the safety of motorists and responders who are at risk of secondary crashes, near-miss encounters and struck-by incidents. To mitigate these hazards, the Federal Highway Administration has made Traffic Incident Management and Quick Clearance a priority. The success of this strategic, coordinated process relies on the cooperation of private- and public-sector partners across the nation.

For crash investigators and reconstructionists, Quick Clearance has its challenges. “One of the issues we have is that, when we’re undertaking a crash reconstruction, we need to get very accurate measurements of the physical evidence at the scene—it might be vehicle positions, tire marks, gouge marks and other types of evidence,” said Lt. Andrew S. Klane, commander of the Massachusetts State Police Collision Analysis and Reconstruction Section (C.A.R.S.), which processes 400 to 500 cases per year for the commonwealth. “The challenge was to find a way to accurately document and gather that data but do it in a very timely manner.”

An Innovative Approach to Crash Investigations

Viva GNSSThe solution for Klane was to look to the agency with which his section works closely—the Massachusetts Department of Transportation, which uses Leica Geosystems’ global navigation satellite system (GNSS) solutions (commonly referred to as “GPS”). “This is a collaborative effort,” Klane explained. “We’re using a lot of MassDOT’s line coding and templates, and it made sense to look at the equipment they were using.”

Accuracy was also a key consideration. “Our reconstructions are only as good as the accuracy of the measurements and evidence that we have,” Klane said. “The GNSS equipment is good to three centimeter accuracy, which is well above the accuracy that we require.” The GNSS technology also is easily deployed by one person. “All of that would allow us to process our crash scenes faster, more accurately and, ultimately, get the roads open.”

With the assistance of MassDOT, C.A.R.S. began purchasing Leica Geosystems GNSS mapping systems in 2012. The compact systems—comprising a field controller, GNSS receiver and pole—are kept in C.A.R.S. cruisers at all times for immediate access. “We have 24 troopers across the state, and their primary role is to reconstruct fatal and serious-injury crashes that may result in some type of prosecution,” Klane said. “Those cases are the ones we use this equipment at.” His ultimate plan is to equip each cruiser with the technology. “We have nine of them,” he said. “My goal is for every one of my people to have one.”

GNSS Technology Takes Crash Investigation to Greater Heights

The GNSS mapping systems, Klane said, have taken C.A.R.S.’s documentation and evidence collection capabilities to “the next level.” In the past, his section relied exclusively on total station technology. “With just total stations, you’re referencing an arbitrary point, and everything is in relationship to that, but it doesn’t put you ‘on the world’—it doesn’t put you into any exact location,” Klane said. “Now, with GNSS, we’re geo-referencing everything.”

Since MassDOT maintains its own continuously operating reference stations (CORS), C.A.R.S. accesses the network for its ground connection. The real-time network enables Klane’s troopers to begin mapping moments after arriving on the scene. “We’re getting about a three- to five-second acquisition on points,” Klane said.

In addition to fast acquisition times, the technology allows C.A.R.S. troopers to concentrate on key evidence. “By going off a CORS network, we can get referenced and shoot the evidence from the crash, but the layout of the road and roadway features can be obtained with GIS images or as-builts that were completed of the roadway. Whereas before, we would have to shoot everything—edges of road, guardrails, pavement markings, etc.—we don’t have to do that anymore because we get it from another data source. So that’s why the CORS network, the geo-referenced data, is such a huge benefit.”

Easy-to-Use and Versatile Software

Another advantage Klane discovered is that the Leica software is simple to navigate. This is especially valuable when training people unfamiliar with mapping technology. “That newer officer,” Klane said, “or someone who doesn’t have a lot of experience with this type of equipment and technology can be taught how to use the software and become proficient with it in a short period of time.”

Once the data is collected, drawings are created in AutoCAD Civil 3D, which interfaces seamlessly with the Leica software. This recent transition to AutoCAD further aligns C.A.R.S. with MassDot formats. “We’re starting with their CAD protocol, and we’re adopting it to ours,” Klane said. “This integration allows us to take points of evidence only and then obtain from MassDot either the GIS images or the actual plans in AutoCAD of the roadway so we can reconstruct a section of road.” In addition to integration with MassDOT’s AutoCAD Civil 3D protocol, the software can be integrated with other measuring technology, including total stations and laser scanners. “So depending on the crash,” Klane said, “we can pick the correct tool to use.”

With varied equipment and software, including Leica Viva, C.A.R.S. and the Commonwealth of Massachusetts are meeting the documentation and evidence-collection challenges of Quick Clearance following serious-injury and fatal vehicular collisions. “There’s no one tool,” Klane said, “but this technology is a very successful tool in this time-sensitive environment.” The GNSS mapping systems enable C.A.R.S. investigators to carry out highly accurate and detailed reconstructions and reduces the time officers are at the scene. “From what we’ve seen,” Klane said, “we’re cutting the scene processing time by about half, which is very significant for us.

“If we can clear the road, not only are we helping the public by getting the traffic back to normal and allowing them to go about their day but we’re also getting police officers off the road so they’re out of harm’s way.”

For more information on geospatial measurement solutions for accident investigation and reconstruction, contact us.

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