Partial Automation Doesn’t Make Vehicles Safer

Early on the morning of 3 September, a multi-car accident occurred on Interstate 95 in Pennsylvania, raising alarms about the dangers of relying too heavily on advanced driver assistance systems (ADAS). Two men were killed when a Ford Mustang Mach-E electric vehicle, traveling at 114 kilometers per hour (71 mph), crashed into a car that had pulled over to the highway’s left shoulder. According to Pennsylvania State Police, the driver of the Mustang mistakenly believed that the car’s BlueCruise hands-free driving feature and adaptive cruise control could take full responsibility for driving.

The crash is part of a worrying trend involving drivers who overestimate the capabilities of partial automation systems. Ford’s BlueCruise system, while advanced, provides only level 2 vehicle autonomy. This means it can assist with steering, lane-keeping, and speed control on prequalified highways, but the driver must remain alert and ready to take over at any moment.

State police and federal investigators discovered that the driver of the Mustang involved in the deadly I-95 incident was both intoxicated and texting at the time of the crash, factors that likely contributed to their failure to regain control of the vehicle when necessary. The driver has been charged with vehicular homicide, involuntary manslaughter, and several other offenses.

Are Self-Driving Cars Safer?

This incident is the latest in a series of crashes involving Mustang Mach-E vehicles equipped with level 2 partial automation. Similar accidents were reported earlier this year in Texas and Philadelphia, all occurring at night on highways and resulting in fatalities. In response, the National Highway Traffic Safety Administration (NHTSA) launched an investigation into the crashes and the role ADAS systems may have played in them.

Unfortunately, there isn’t good data on the proportion of fatal crashes involving vehicles equipped with these partial automation systems. —David Kidd, Insurance Institute for Highway Safety

This is not a niche issue. Consulting and analysis firms including Munich-based Roland Berger predict that by 2025, more than one-third of new cars rolling off the world’s assembly lines will be equipped with at least level 2 autonomy. According to a Roland Berger survey of auto manufacturers, only 14 percent of vehicles produced next year will have no ADAS features at all.

“Unfortunately, there isn’t good data on the proportion of fatal crashes involving vehicles equipped with these partial automation systems,” says David Kidd, a researcher at the Arlington, Va.–based Insurance Institute for Highway Safety (IIHS). The nonprofit agency conducts vehicle safety testing and research, including evaluating vehicle crashworthiness.

IIHS evaluates whether ADAS provides a safety benefit by combining information about what vehicles come equipped with with data maintained by the Highway Loss Data Institute and police crash reports. But that record keeping, says Kidd, doesn’t yield hard data on the proportion of vehicles with systems such as BlueCruise or Tesla’s Autopilot that are involved in fatal crashes. Still, he notes, looking at information about the incidence of crashes involving vehicles that have level 2 driver assistance systems and the rate at which crashes happen with those not so equipped, “there is no significant difference.”

Asked about the fact that these three Mach-E crashes happened at night, Kidd points out that it’s not just a coincidence. Nighttime presents a very difficult set of conditions for these systems. “All the vehicles [with partial automation] we tested do an excellent job [of picking up the visual cues they need to avoid collisions] during the day, but after dark, they struggle.”

Automated Systems Make Riskier Drivers

IIHS released a report in July underscoring the danger of misusing ADAS systems. The study found that partial automation features like Ford’s BlueCruise are best understood as convenience features rather than safety technologies. According to IIHS President David Harkey, “Everything we’re seeing tells us that partial automation is a convenience feature like power windows or heated seats rather than a safety technology.

“Other technologies,” says Kidd, “like automatic emergency braking, lane departure warning, and blind-spot monitoring, which are designed to warn of an imminent crash, are effective at preventing crashes. We look at the partial automation technologies and these collision warning technologies differently because they have very different safety implications.”

The July IIHS study also highlighted a phenomenon known as risk compensation, where drivers using automated systems tend to engage in riskier behaviors, such as texting or driving under the influence, believing that the technology will save them from accidents. A similar issue arose with the widespread introduction of anti-lock braking systems in the 1980s, when drivers falsely assumed they could brake later or safely come to a stop from higher speeds, often with disastrous results.

What’s Next for ADAS?

While automakers like Ford say that ADAS is not designed to take the driver out of the loop, incidents like the Pennsylvania and Texas crashes underscore the need for better education and possibly stricter regulations around the use of these technologies. Until full vehicle autonomy is realized, drivers must remain vigilant, even when using advanced assistance features.

As partial automation systems become more common, experts warn that robust safeguards are needed to prevent their misuse. The IIHS study concluded that “Designing partial driving automation with robust safeguards to deter misuse will be crucial to minimizing the possibility that the systems will inadvertently increase crash risk.”

“There are things auto manufacturers can do to help keep drivers involved with the driving task and make them use the technologies responsibly,” says Kidd. “IIHS has a new ratings program, called Safeguards, that evaluates manufacturers’ implementation of driver monitoring technologies.”

To receive a good rating, Kidd says, “Vehicles with partial automation will need to ensure that drivers are looking at the road, that their hands are in a place where they’re ready to take control if the automation technology makes a mistake, and that they’re wearing their seatbelt.” Kidd admits that no technology can determine whether someone’s mind is focused on the road and the driving task. But by monitoring a person’s gaze, head posture, and hand position, sensors can make sure the person’s actions are consistent with someone who is actively engaged in driving. “The whole sense of this program is to make sure that the [level 2 driving automation] technology isn’t portrayed as being more capable than it is. It does support the driver on an ongoing basis, but it certainly does not replace the driver.”

The European Commission released a report in March pointing out that progress toward reducing road fatalities is stalling in too many countries. This sticking point in the number of roadway deaths is an example of a phenomenon known as risk homeostasis, where risk compensation serves to counterbalance the intended effects of a safety advance, rendering the net effect unchanged. Asked what will counteract risk compensation so there will be a significant reduction in the annual worldwide roadway death toll, the IIHS’s Kidd said “We are still in the early stages of understanding whether automating all of the driving task—like what Waymo and Cruise are doing with their level 4 driving systems—is the answer. It looks like they will be safer than human drivers but it’s still too early to tell.”

​IEEE Spectrum