Unmanned Aircraft System (UAS) for Collision Reconstruction

North Carolina State Highway Patrol

In this Case Study You Will Learn:

  1. Crash documentation has developed from measuring tape and camera to 3D imaging to significantly benefit the collisions reconstruction process.
  2. UAS mounted 3D scanners significantly reduce the time to reconstruct a crash.
  3. Increase efficiency allows for more rapid cleanup of debris and decreased time of road closures.


The North Carolina State Highway Patrol (NCSHP) Collision Reconstruction Unit is made up of five regional office or teams across all 100 counties in the state. Technological advances over the past few years have provided a new level of detail when measuring and documenting collisions.

TSMO Planning, Strategies, and Deployment

The previous method of measuring and documenting collisions was to use a measuring tape and a Nikon Total Station to establish ground control points (GCP). While this was an effective and accurate method, the finished product is lacking in appearance for what has become expected given the advancements in technology.

The SHP has become more accustomed to using laser scanners capable of producing 3D images that are accurate, detailed, and measurable at just over 0.20 of a mile. Additionally, this method involves significant time savings. While initial assessment and setup are required, a black‐and‐white scan can be performed in just four minutes and a color scan in just seven minutes. Including post‐processing time, the reconstruction images are typically available in a couple of hours. The finished product is a 3D visualization and can be captured in darkness. The following image is an example of a six‐vehicle collision involving a tractor‐trailer with three fatalities. This was scanned in total darkness.

Communications Planning and Execution

In May 2017, a study was conducted at the Buncombe County Public Safety Training Facility of a crash reconstruction using the Unmanned Aircraft System (UAS). This was a combined exercise of the UAS Program Office, Division of Aviation – NCDOT, and NCSHP Collision Reconstruction Unit. The scene was mapped by the NCDOT DOA UAS Flight Team using three different drones. The NCSHP Collision Reconstruction Unit mapped the same scene with the 3D laser scanner. A 40 mph head‐on collision was conducted.

The time required to map the incident favors a UAS method over traditional methods. The UAS methods were completed in just 25 minutes, while the 3D terrestrial scanner took 1 hour 51 minutes. The finished product of both provided accurate, color, 3D representations of the incident.

Outcome, Learnings, and Public Benefit

The increased efficiency that UAS provides in measuring and documenting an incident allows debris clearing and clean‐up to be performed more quickly, this is of significant interest to the NCDOT & NCSHP. The impacts to lane or road closures is shortened and causes less travel‐related impacts. More importantly, this method reduces exposure time of first responders to traffic, thereby preserving the safety of personnel at the scene.

Operations Area of Practice

  • Emergency Transportation Operations
  • Roadway Safety Services / Roadway Safety Patrol
  • Traffic Incident Management

Organizational Capability Element

  • Traffic Incident Management
  • Public safety agency collaboration

Content Type

  • Case Studies & Lessons Learned

Publishing Organization

  • NOCoE

Document Downloads

Issue Date
July 10th, 2019
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