Approaching a driver during a traffic stop is typically a moment of heightened awareness for law enforcement officers.

But what happens when vehicle that just came to a halt on the highway shoulder has no driver?

This was just one of numerous autonomous vehicle scenarios Virginia Tech Transportation Institute (VTTI) researchers have been helping develop answers for during the past four years.

“We have a series of displays with the capability to interact with a police officer, including being able to contact a fleet manager and talk to a human to help resolve the issue,” said Mike Mollenhauer, division director of technology implementation at VTTI. “We’re trying to figure out how they can do what they need done and do it safely, as well as some of the issues related to how the vehicle is going to identify someone who is or is not an authority and what authority they should have over the vehicle.”

The technology was one of several feats on display during the Safely Operating ADS (Autonomous Driving Systems) in Challenging Dynamic Scenarios project demonstration in Arlington this week. The event featured VTTI’s Level 4 autonomous Ford F-150 moving through numerous public safety interactions on the Interstate 395 express lanes.

“Level 4 means that within a certain spectrum of operational designs — such as a certain type of roadway and in certain weather conditions — the vehicle should be able to operate itself without the expectation of a driver taking over,” Mollenhauer said. “Right now, from a driver capability perspective, you can think of it as sort of like a toddler. It can do a lot of things, but it can also get itself into trouble because it doesn’t have a lot of experience yet.”

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To help gain that experience, the truck was tasked with navigating 18 situations, including interacting with roadside workers, first responders, and other drivers. The parameters for the trials were developed in partnership with

  • Virginia Department of Transportation
  • Crash Avoidance Metrics Partners LLC, a consortium of vehicle manufacturers consisting of Ford, GM, Mercedes-Benz, and Nissan
  • Transurban North America, a global toll road company that oversees the Interstate 495, 95, and 395 express lanes and incorporates smart technology in roadways

“Through projects like this, we're hoping to take the ‘ominous out of autonomous,’” said Joe McLaine, safety engineer for General Motors and chairman of Crash Avoidance Metrics Partners LLC.  “We want to let folks know — the driving public, the riding public, and folks such as first responders and emergency services who will continue to interact with these vehicle systems in the not too distant future — we want to let all of them know that the automakers, the OEMs [original equipment manufacturers] developing and deploying this technology, along with trusted partners like VTTI are taking all of these scenarios into consideration from the very get-go.” 


computer interface on truck window
VTTI researchers developed a computer interface to allow authorities to interact with the vehicle. Photo by Craig Newcomb for Virginia Tech.

Along with traffic stops, other scenarios included

  • Detecting and maneuvering around out-of-sight hazards by communicating with roadway technology
  • Navigating around first responders and work zones, including detecting lane change prompts and executing the merge.
  • Responding to emergency vehicles
  • Identifying and following hand signals provided by a authority the vehicle recognizes
  • Using real-time speed and distance information from the roadway in order to create tight vehicle formations

The demonstration was in part the result of a $7.5 million U.S. Department of Transportation and Federal Highway Administration grant, which the project partners and VTTI received in 2019. Since then, the VTTI research team has worked with its collaborators to not only develop the project parameters but also to outfit the 2022 hybrid truck with technology that can require as much as 120 amps to operate.

Mollenhauer said that while the project has made great progress, it also has revealed many unanswered questions related to public safety and autonomous vehicles. Those are areas VTTI plans to continue to work with public and private partners to address through its research.

“That means expanding on some of the capabilities we’ve developed and perhaps building on some of them by really getting out there and having the people that do this work – fire, EMS [emergency medical services], law enforcement – interacting with and trying out these vehicles to give us feedback,” Mollenhauer said.

Another demonstration is scheduled for November.

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