Unmanned Aircraft Systems for Traffic Incident Management

Chapter 3. Benefits of Unmanned Aircraft Systems for Traffic Incident Management

The following list represents some of the benefits of Unmanned Aircraft Systems (UAS):

• Easy to Use.
• Provides Aerial Views of The Scene.
• Shorter Road/Lane Closures.
• Less Time on Scene.
• Less Time in Roadway.
• Lower Cost Aerial Images vs. Manned Aircraft.
• Lower Cost of Investigative Man Hours.
• Fewer Errors Transposing Manual Measurements.
• Faster Crash Investigations.
• Safety of Incident Responders.
• Reduced Likelihood of Secondary Crashes.
• Saves Time Required for Data Collection.
• Provides Immediate Viewing of Images.
  • Ability to live stream images to another location.
  • Fewer Impacts on Commerce.
  • Cost Effective Measuring and Mapping Solution.
    • Scalable versus Three-Dimensional (3D) Light Amplification by Stimulated Emission of Radiation (Laser).
    • Distributed Storage versus Central Storage.
    • Less Expensive than Total Station and 3D Lasers.
    • Less Maintenance Cost Compared to 3D Lasers.
• Improved Investigative Outputs.
  • Aerial Views.
  • Modeling Possible.
  • Easy for Layperson to Understand.
• Better Situational Awareness.

Law enforcement has noted that having access to overhead images at crash scenes helps them better understand vehicle movement and the dynamics of the crash.¹⁶ Measurements from photographs is the major benefit for traffic crash investigation using UAS, as all users noted that UAS was much faster than any other scene measuring or mapping technique.

In general, mapping with Total Station could involve 100 to 200 points, requiring up to two hours, and the roadway is often fully or partially closed for safety reasons. While 3D scanners create point clouds with millions of points, closing the road is routine with their use. UAS may take 100 to 200 photographs, containing millions of points in a 10- to 15-minute flight where the roadway can generally stay open.

Collecting points with total station or scans with 3D scanners require more actions as scenes get larger or more complex. Additional points and scans require more time. Regardless of complexity, size of the scene, or number of vehicles, the UAS time is virtually the same for most traffic crash scenes.

A study by the National Institute of Justice (NIJ) used technology at a staged traffic collision to determine accuracy of the approaches and to a lesser degree time savings. The NIJ study compared UAS with the use of both manual and robotic total stations and found that UAS was one hour faster than the robotic total station and two hours faster than the manual total station.¹⁷

The North Carolina Department of Transportation (NCDOT) and North Carolina State Highway Patrol (NCSHP) completed a field comparison that provides the most cited evidence that UAS represents a time savings over 3D laser mapping. The two approaches were the same from an accuracy standpoint, but the UAS approach demonstrated significant time savings. UAS was found to be 311 percent more efficient, requiring just 25 minutes to document a staged two-car collision, while the 3D scanner required one hour and 51 minutes.¹⁸

In a study with Purdue University, the Tippecanoe, Indiana Sheriff’s Office found that overall scene time was reduced by 60 percent with the use of UAS.¹⁹ In one example, the agency noted that an 800-foot crash scene was documented in a mere 22 minutes.

The Washington State Patrol (WSP) has data that shows the effectiveness and value of UAS as a tool for actual traffic crash investigations during their 2018 pilot program.²⁰ The WSP has documented more than 125 UAS deployments and found:

• Unmanned aerial vehicles (UAV) provide an 80 percent reduction in road closure time compared to other methods to measure scenes.
• The estimated fiscal impact of road closures is $350 per minute to the State in economic impact.
• The 2018 UAV pilot project provided an economic savings of $4,210,500.
• Investigators are safer—they are not in the roadway taking measurements and they clear the scene quicker, minimizing exposure to risks.

Figure 8 shows a graphic summary of the time savings for road closures with UAS compared to traditional tools.

Figure 8. Slide. Key results slide from Washington State Patrol presentation.
(Source: Washington State Patrol.)

Time and safety create very compelling cases for clearing traffic incidents more quickly. The juxtaposition is the need for a complete and thorough crash investigation, particularly when there is a fatality and potential criminal charges. The concept of “safe, quick clearance” is a national traffic incident management (TIM) objective and represents the belief that safety and expedience are complementary objectives. With UAS time and quality are both potentially improved.

While only a few examples provide empirical evidence, more than 45 “anecdotal” benefits attributed to the use of UAS for traffic crash mapping were identified in media accounts. Some examples of anecdotal benefits:

• Crashes that took three to four hours were down to 20/30 minutes using UAS.
• Three hours versus 45 minutes with UAS.
• Contract helicopters cost $400 per hour and UAS only costs $20 per hour.
• Cuts scene time by 80 percent and measuring time by 66 percent.
• Cuts scene time by 80 percent and measuring time by 66 percent.
• Average flight takes 15 minutes, reducing traffic backup by hours.
• Three hours down to 15–30 minutes.
• Cleared a DUI crash in one hour versus three hours.
• Three hours to 15 minutes.
• More accurate than manual methods.
• Seven-minute flight to cover a three-acre scene.
• A 75–80 percent reduction in mapping time.
• Four to five hour crashes are cleared in half the time.
• Shorter road closures, quicker measurements.
• Mapping went from 1.5 hours to 15 minutes.