The increasing adoption of distributed testing (DT) systems—where multiple interconnected systems can execute tests interactively in real time—presents a powerful opportunity for intermodal collaboration. U.S. Department of Transportation’s Highly Automated Systems Safety Center of Excellence (HASS COE) recently launched a series of webinars and workshops dedicated to increasing knowledge about DT across USDOT. But what are DT systems and how can USDOT “plug in” together?

Overview of DT

A HASS COE-hosted DT 101 workshop in May 2024 defined DT as the practice of systematically connecting and testing live or simulated geographically dispersed actors simultaneously. Distributing the testing process across multiple virtual and physical locations or nodes can leverage the strength of each of these dissimilar systems in combination to improve test performance, coverage, and possibly scale. By connecting disparate testing resources, DT allows for more efficient and nimble test execution, supports a wide range of software and hardware platforms and configurations, and enhances the ability to identify and address issues in complex, large-scale systems. All these advantages support USDOT’s efforts to increase safety in the Nation’s transportation systems through more comprehensive verification and accelerate safety-related technology advancements.

Impact of DT on Current Testing Protocol

The transition to DT is not a whole-scale redesign of USDOT verification processes; rather, DT complements, builds upon, and expands the utility of systems widely in place across USDOT today.

“Fundamentally, DT does not replace traditional full-system verification,” says Dr. Joshua Every, senior scientist at HASS COE. “But it does enable us to get information on system of systems interactions earlier in the process. We get testing data before deployment, so we can gain experience before the final event. Rather than spending months at a test site, DT allows for faster, more nimble data collection, and prioritization of our time in the field.”

Current Status of DT at USDOT

USDOT has the technology building blocks in place to implement DT—for example, existing hardware-in-the-loop systems, full-scale vehicle testing capabilities, infrastructure systems, and human-in-loop simulators—that are all valuable tools in isolation. The initial challenge for wider adoption of DT is to standardize the way teams communicate about DT and to align on key terminology across USDOT.

“Our goal is to establish organizational alignment,” says Dr. Every. “We want to standardize organizational norms and build consensus on key terms up front.”

Case Study of USDOT DT

The Federal Highway Administration recently deployed DT processes in its Pilot-2 project. FHWA worked with seven external research partners, each with their unique test systems and organizational knowledge.

“The logistics of coordinating and connecting so many research partners in realtime was a challenge,” says Danielle Chou, a program manager for enabling technologies at FHWA’s Office of Safety and Operations Research and Development (R&D). “But the potential return was invaluable: the collective research team demonstrated how DT enabled us to connect a trove of testing resources that we otherwise would not have been able to access or fully fund ourselves, including a physical chassis dynamometer test stand at Argonne National Lab, a physical test track at the University of Michigan, and five independent simulated vehicle models. This kind of testing enables us to collectively maximize our use of existing R&D investments across government, industry, and academia.”

Next Steps for DT at USDOT

With DT pilot programs already in place at USDOT, organizational-level direction will continue to empower the teams within USDOT adopting new technology and will likely lead to the discovery of programs and systems in place today that could benefit from DT methodologies. HASS COE’s DT workshops and webinars were held from July to October 2024 and will continue into 2025.

Steve Nelson is a communications director at a consulting group and is currently working with USDOT HASS COE. He is responsible for writing and editing original content for the HASS COE communication channels. He received his M.F.A. in fiction from Columbia University and his B.S. in psychology from Vanderbilt University.

For more information, contact Denise Bakar, HASS COE communications manager at denise.bakar@dot.gov or go to https://www.transportation.gov/hasscoe.