Automakers and tech companies are sinking billions of dollars into research and development for autonomous (self-driving) vehicles. Because cars and light trucks for the most part still have internal combustion engines and the same basic mechanical parts (tires, steering wheels, axles, etc.) as cars built 50 years ago, the rush to develop self-driving vehicles is essentially a technology race.
The Insurance Institute for Highway Safety (IIHS) on Tuesday released a new study of autonomous driving technology in five popular cars sold in the United States. All five were tested and judged on their compliance with Level 2 autonomy on the SAE automation scale.
The scale runs from level 0 to level 5, indicating a range of no autonomy to full autonomy. The two systems IIHS evaluated were adaptive cruise control (ACC), a technology that maintains a set speed and following distance from a vehicle in front, and active lane-keeping, a technology that provides input to the vehicle’s steering. Both technologies require drivers to keep their hands on the steering wheel. In essence, the driver’s responsibilities are no different than if the technology were not present.
The five cars evaluated by IIHS all were equipped with automatic emergency braking systems that IIHS had rated as superior:
- 2017 BMW 5-series with “Driving Assistant Plus”
- 2017 Mercedes-Benz E-Class with “Drive Pilot”
- 2018 Tesla Model 3 with “Autopilot” software version 8.1
- 2016 Tesla Model S with “Autopilot” software version 7.1
- 2018 Volvo S90 with “Pilot Assist”
The ACC systems were tested on the track and in the real world. IIHS concluded:
The outlook is promising for the potential safety benefits of ACC. The technology is often bundled with forward collision warning and autobrake, and research by IIHS and HLDI has found crash-reduction benefits for these systems combined. A federally sponsored study found that drivers using ACC have longer, safer following distances than drivers who don’t use ACC. Still, IIHS tests indicate that current ACC systems aren’t ready to handle speed control in all traffic situations.
Active lane-keeping technology drew a more measured response from IIHS:
The evidence for safety benefits of active lane-keeping systems isn’t as pronounced as for ACC. Still, the potential to prevent crashes and save lives is large. IIHS research shows that preventing lane-departure crashes could save nearly 8,000 lives in a typical year (see “New estimates of benefits of crash avoidance features on passenger vehicles,” May 20, 2010). Lane-departure warning systems are associated with an 11 percent reduction in the rates of single-vehicle, sideswipe and head-on crashes of all severities and a 21 percent reduction in the rates of injury crashes of the same types.
IIHS chief research officer, David Zuby, said:
Designers are struggling with trade-offs inherent in automated assistance. If they limit functionality to keep drivers engaged, they risk a backlash that the systems are too rudimentary. If the systems seem too capable, then drivers may not give them the attention required to use them safely.
We’re not ready to say yet which company has the safest implementation of Level 2 driver assistance, but it’s important to note that none of these vehicles is capable of driving safely on its own. A production autonomous vehicle that can go anywhere, anytime isn’t available at your local car dealer and won’t be for quite some time. We aren’t there yet.
Recent real-world crashes involving vehicles with Level 2 automation illustrate how much the technology has yet to develop. The full IIHS report with details of all the testing and scores for each vehicle is available at the organization’s website.