Self-driving vehicles won't be widely viable commercially until their AI guidance systems are better than human drivers and can adjust to unpredictable road circumstances.
When electric car giant Tesla recently introduced a beta of it latest full self-driving software then withdrew it, the abrupt reversal encapsulated the stop-start state of autonomous vehicle technology.
In a tweet on Oct. 23 about the withdrawal of the system, Tesla CEO and founder Elon Musk said it's impossible at this point to test all configurations of a fully self-driving vehicle.
That dilemma is at the heart of the fitful progress on autonomous vehicle technology by major automakers such as Ford, General Motors and Hyundai, and tech giants including Apple, Google's Waymo subsidiary and Amazon's Zoox robotaxi subsidiary.
The industry must also overcome daunting challenges in ensuring safety.
While Tesla cars now have only limited autonomous capabilities, the company has made significant advancements, including putting cars on the road with limited self-driving features.
But some experts say Tesla's chief limitations stem from a sensor suite that is not quite diverse enough. And different iterations of that problem also afflict other developers of autonomous vehicle technology.
Tesla relies on mainly cameras and software to perform all aspects of sensing the environment surrounding the car, leaving its level of autonomy at what is known in the industry as level 2, meaning the driver's hands must always be on the wheel. Others in the industry that are developing level 3 or 4 technology (vehicles that don't require limited help from the driver or don't require a safety driver) are using a combination of cameras, software, lidar, radar and updateable HD maps.
"The advantage to adding these additional sensor modalities is that it provides redundancy across environmental conditions … and road types, and provide[s] an alternative method to distinguish certain roadway elements and actors," said Matt Arcaro, an analyst at IDC.
Advances in autonomous vehicle technology
A prominent vendor in this area is Waymo. The Google subsidiary runs a self-driving taxi service in a section of Phoenix.
The vendor is also working on using the technology in other areas such as trucking, logistics and personal vehicles. Recently Waymo and GM's Cruise division were the first autonomous vehicle technology vendors to obtain autonomous vehicle permits in California that would allow them to transport passengers.
Other promising projects involve traditional and new automotive manufacturers working on autonomous technology for robotaxis and personal vehicles.
For example, in 2019 Volkswagen said it would join Ford in investing in AI vendor Argo AI to introduce autonomous vehicle technology in the U.S. and Europe. The companies committed to spending more than $4 billion through 2023 to develop their self-driving service.
Another involves Intel subsidiary Mobileye and SIXT, a provider of mobility services in Germany; the vendors plan to offer robotaxis in Munich next year.
Amazon's Zoox is designing autonomous vehicles from the ground up. The Zoox strategy is distinguished by its unique model, which is not designed like a car and doesn't have a front or a back end or even a steering wheel.
The safety issue with autonomous vehicles
Despite the advances in the technology and interest in it from the public and enterprises, the autonomous vehicle industry is still up against many challenges, chief among them safety.
Although the industry is making progress in trying to make sure the technology is safe, regulation that could enforce safety requirements is largely absent, and it is mostly unclear still how local authorities will administer laws and regulations governing the use of autonomous vehicles.
Some states have enacted legislation for autonomous vehicles. Nevada requires manufacturers to meet detailed testing and safety rules; maintain a $5 million insurance policy to test vehicles on public roads; and, as of now, place a safety driver on board.
"If it's vague out there that you're relying on each individual provider to come up with their own definition of safety, that's not the right way to do it," Arcaro said.
And if autonomous vehicles are not as safe or even safer than human drivers, then there's no point to them, said Sam Abuelsamid, an analyst at Guidehouse.
Abuelsamid noted that while human drivers are criticized for being responsible for most crashes, people are good at driving and most of the time they drive, they don't crash.
"We have not yet proven that autonomous vehicles can do the same, especially in the more challenging conditions," he said. "We will undoubtedly have more crashes and more fatalities with autonomous vehicles because it's impossible to make a system that complex perfect. But if we make it better than humans, then we'll make progress."
The uses of autonomous vehicle technology
Another challenge with the technology is figuring out where it's useful.
Vendors such as Waymo, Uber and Motional -- a joint venture between Hyundai and autonomous vehicle technology vendor Aptiv -- are using the technology to develop robotaxis.
However, the goal and challenge for businesses is to find wide applications for the technology that can help them make money.
One industry that's crying out for autonomous vehicles is trucking, which is suffering from a widespread shortage of drivers. An autonomous vehicle out on the highway is much simpler than guiding a vehicle autonomously in the city.
Waymo's Via system uses cameras, software, lidar and radar configured to the specific requirements of truck driving. Startup vendor Aurora has put autonomous trucks on the road with backup human drivers. However, Aurora hopes to remove the drivers by 2023 when It fully launches its trucking business.
While there appears to be a real need for autonomous vehicles in the trucking business, Arcaro said other sectors are interested too, but self-driving is not like "turning on a light switch."
"A lot of enterprises are a little skeptical because of initial timelines, but they're also open to the technology," Arcaro said.