How Safe is Safe Enough?
Feb. 15, 2021—Automakers, legislators, and technology companies are all racing to create the industry’s first fully-autonomous vehicle. But in order for that to happen, its level of safety must be proved over and over again.
During a recent webinar hosted by Partners for Automated Vehicle Education, Jack Weast, senior principal engineer at Intel and the vice president of automated vehicle standards at Mobileye, and Mike Wagner, CEO and co-founder of Edge Case Research, defined what makes a safety case.
Safety cases have been used for years by a variety of industries, but now, the framework that guides safety cases is being applied to the deployment of autonomous vehicles.
“The technology is new, but the safety approaches don’t necessarily have to be,” Wagner said.
What is a safety case?
“A safety case is a structured argument that provides evidence on why the product you built achieves the safety goals you set for it,” explained Weast. Safety cases function as a framework that allows you to tie empirical data back through.
A safety case does not immediately give a company the green light to test their latest autonomous vehicle, but it is a benchmark to ensure the vehicle is completing its tasks as it was programmed to.
But safety cases are not about “perfect safety,” Weast said. They’re for documenting risk.
Wagner said safety cases have been used for decades, specifically in aviation and aerospace engineering.
In 1997, an aviation safety case was made by the Commercial Aviation Safety Team that reduced fatality risks in the U.S. by 83 percent from 1998 to 2008.
“Safety cases stem from the need to be able to communicate safely,” Wagner said.
Safety Cases for AVs
Safety cases are used for the operation of autonomous vehicles in a myriad of ways. One of which is to make “reasonable worst-case assumptions,” Weast said.
Take driving past pedestrians, for example. “We drive by them at 30 or 40 miles per hour, based on the assumption that they will not veer out of their lane and neither will the driver,” he said.
Assumptions about pedestrian’s movement is one thing to predict, but Weast said it gets much more complicated.
“Should autonomous vehicles be designed to let planes land on the interstate?” he posed to the virtual audience. “It happens, but not often.”
Safety cases help to ensure that the right assumptions are being made in the right place and at the right time, Weast said. “Safety cases provide a framework for regulation to provide values to the assumptions.”
Framework Versus Formula
Throughout the presentation, Weast stressed the importance of viewing safety cases as a framework, not a set formula, for safety.
He said a safety case is not an opportunity to “grade your own homework,” or to be used as a publicity stunt.
“If you treat safety cases like a PR exercise, you’re going to miss important things,” he said.