Ford, having noted engineers monitoring self-driving cars are dozing off, has decided to remove the steering wheel, brake and accelerator pedals from its driverless cars arriving in 2021, a media report said.

Bloomberg noted that sets Ford apart from most automakers which believe drivers can be counted on to take the wheel if an accident is imminent.

The report said BMW, Mercedes-Benz and Audi plan to roll out semi-autonomous cars starting next year that require drivers to take over with as little as 10 seconds notice - Level 3 autonmous on the SAE scale - more capable than cars where drivers do everything, but short of full automation.

Ford, however, plans to skip that level altogether after aligning with Alphabet's Waymo which made similar discoveries related to human inattention while researching Google's driverless car.

"Level 3 may turn out to be a myth," Waymo chief executive officer John Krafcik told Bloomberg of autonomous cars that require human intervention. "Perhaps it's just not worth doing."

The report said Ford and Waymo's views show there's a rift developing among the creators of autonomous cars over what role - if any - humans should play when cars begin driving themselves. Most automakers believe that, at least initially, people must supplant the robot to avoid crashes in complex situations. Others contend that asking an inattentive human to respond in seconds to a life-or-death situation is a recipe for disaster.

"There's evidence to suggest that Level 3 may show an increase in traffic crashes," Nidhi Kalra, co-director of the Rand Center for Decision Making Under Uncertainty, said this week during a US congressional hearing, according to Bloomberg. "I don't think there's enough evidence to suggest that it should be prohibited at this time, but it does pose safety concerns."

Advocates of Level 3 contend a human backup is required for safety and to allow consumers to become comfortable with technology that will eventually take the wheel from their hands, the report noted.

"We like the levels," Scott Keogh, president of Audi of America, told Bloomberg at a conference in Las Vegas this year. "It helps with consumer understanding and getting trust built into the marketplace, as opposed to going straight to the moonshot right off the bat."

Next year, Audi will introduce Traffic Jam Pilot, a Level-3 system that allows hands-free driving at speeds of up to 35 miles per hour. If the car's sensors detect a situation that requires human help, it will give the driver 10 seconds to get hands on wheel, eyes on road, foot on pedals. If the driver doesn't respond, the car will slow to a stop in its lane.

Other automakers, such as Nissan Motor and Honda, have systems coming that will give drivers 30 seconds to prepare to re-engage and that can pull to the side of the road if the car doesn't detect human hands on the wheel.

"You can even go to sleep and the car can wake you up," Amnon Shashua, co-founder and chief technical officer of autonomy supplier Mobileye, which is providing Level 3 systems to Audi, BMW, Honda and others, told Bloomberg. "You know, waking up for 30 seconds is quite a long time."

That's not how Hakan Samuelsson sees it. A person at rest or distracted by e-mail or entertainment can't be expected to quickly take the wheel and save the day, the Volvo Cars CEO told Bloomberg. No sensor exists yet that can predict far enough into the future to give a driver enough time to prepare to avoid a crash, he said.

"We don't believe in five seconds, 10 seconds," Samuelsson said. "It could even be dangerous. If you are doing something else, research shows that it will take two minutes or more before you can come back and take over. And that's absolutely impossible. That really rules out Level 3."

Volvo's view was echoed by company staffers launching the latest S/V90 models to European media last summer. We had been trying Pilot Assist which is a mix of lane departure warning and steering correction which proved able - in conjunction with radar assisted cruise control, which can slow you to a stop and take off again - to steer the car along a gently curving motorway of its own accord so, we tried it hands-off (but not too far from the rim, just in case).

"You should never take your hands off the wheel," lectured a Volvo Cars spokesman when I was discussing this feature with him after a test drive

Bloomberg said Volvo, siding with Ford and Waymo, will deploy a self-driving system in 2020 that won't require human intervention. It's now being tested as a robot taxi by Uber Technologies. Volvo will equip its self-driving XC90 sport utility vehicle with a steering wheel that tucks away while in autonomous mode but also allows its owner to drive manually for pleasure.

"A premium car is one you can use as an office in the morning and then drive it yourself on a nice country road in the evening," Samuelsson said. "You will never end up in no-man's land."

Legal liability could be driving most automakers to put the wheel in the driver's hands in an emergency, said Joe Vitale, global automotive leader for consultant Deloitte, told Bloomberg.

"With a vehicle crash when it's operating in Level 3, I'm sure manufacturers will believe the consumer is responsible because they have their hands on the wheel and they've been alerted," Vitale said. "But I don't think regulators are going to easily turn over on that issue."

Volvo has pledged it will accept responsibility for any crashes by its self-driving vehicles. Samuelsson said Level 3 could create confusion over who is legally liable for a crash.

"It should be black and white," Samuelsson told Bloomberg. "With responsibility, you cannot tell anybody you are a bit responsible. Either you are responsible or you are not."

One matter both sides agree on is that too many requests for human intervention could wreck the autonomous experience.

As part of its testing, Ford used sensors that monitor facial expression and track eye movement to determine if a driver was alert and ready to take over. This led to an unenviable experience in which drivers felt they were being constantly reminded to pay attention.

If Level 3 cars are constantly badgering the driver, Ford CEO Mark Fields has said, owners will wonder: "Why did I spend that extra premium for this if I have to be alert and pay attention?"