Your next car may allow you to drive hands-free. This is a good thing?

Automakers have been adding safety technologies in order to prevent accidents, such as automatic emergency braking and systems to prevent the car from leaving its lane. Now more are introducing features in vehicles that aim to make it less expensive to drive in rush hour traffic or on road trips.

Some new systems allow drivers to take their hands off the steering wheel on highways or in heavy traffic jams, using sensors, radar and cameras to automatically keep the car centered, control speed and even change lanes.

General Motors Co.

was the first major automaker to promote these features in 2017 with the Super Cruise speakerphone feature, which can be activated on most US highways by pressing a button on the steering wheel that allows the car to take control of direction and speed .

The Detroit automaker said it now plans to launch the technology on about two dozen models by 2023, compared to a Cadillac model now.

Ford Motor Co.

F -1.45%

recently said it would offer similar technology starting next year on up to 100,000 F-150 pickups and electric sport utility models Mustang Mach-E.

Honda Motor Co.

HMC -0.45%

plans to launch a sedan in Japan in the coming months that will allow the driver to completely relinquish control of the car in heavy traffic or on highways. The technology will even allow drivers to take their eyes off the road, although they must regain control at any time, the company said. Japanese government regulators approved its use in November.

Honda said it did not reveal plans to introduce this technology outside Japan.

Meanwhile, Tesla Inc.

TSLA 2.44%

said it recently launched a trial version of its updated Autopilot for some owners, the carmaker’s driver assistance feature.

The $ 10,000 feature, which the company calls Full Self Driving, expands the use of automated features for more types of highways and adds features like navigation at road junctions.

The promise of fully driverless cars has vanished in recent years as developers struggle to refine the technology. But automakers are equipping more models with the driverless car building blocks to offer so-called driver assistance packages, in the hope of gaining a competitive advantage and increasing sales.

“They allow car manufacturers to offer really interesting and differentiated features to the consumer at a reasonable price,” said Glen De Vos, chief technology officer at Aptiv PLC, a provider of software and components used in driver assistance systems.

Consumer Reports recently tested 17 models that combine automated steering and speed control, compared to four when the magazine did a similar test two years ago. The magazine said that such systems can relieve driver fatigue, but performance varies widely in aspects such as the smoothness with which they brake and accelerate or keep the car centered on its track.

However, if drivers have fewer tasks behind the wheel, safety advocates are concerned, as they will be tempted to look at their phones or indulge in other distractions, causing accidents.

“If we’re going to put this technology in cars, we need to be careful to make sure the driver is reasonably engaged,” said Bryan Reimer, a research scientist at MIT who studies driver assistance systems.

Some defenders have criticized Tesla for promoting its latest update as autonomous because the system is not fully autonomous, and defenders say a pilot system should not be tested on public roads.

Tesla did not respond to requests for comment. The electric car maker said earlier that accident rates are lower when drivers have vehicles with the Autopilot driver assistance system enabled than when it is not in use.

Car manufacturers have installed camera-based systems that monitor drivers’ focus and alert them if their attention is shifting, say executives and analysts. GM and BMW AG

BMW 1.78%

use technology to keep drivers engaged, and Ford and others plan to use it on future models. These systems have received praise from researchers.

Aptiv’s De Vos said the company is working with five car manufacturers to equip vehicles with camera-based driver tracking systems.

Cadillac owners recorded about 6.5 million hands-free miles using Super Cruise technology, the company said. A series of audible alerts warn drivers if their attention is diverted from the road.

Mario Maiorana, chief engineer of GM’s Super Cruise, said it has become a selling point for customers, noting that 85% of owners say the feature will be an important consideration in their next car purchase.

“People have told us that they feel they arrive at their destination feeling more refreshed and relaxed because of the work we do,” he said.

A recent update has improved driver monitoring technology, he said. Now it can track the driver’s eyes, instead of just the head position, to better detect whether the driver is fixed on the road or elsewhere.

A U.S. Senate bill introduced this year would require the U.S. Department of Transportation to study whether driver monitoring systems can reduce distraction while driving and potentially require them in future models. The legislation, presented by Edward Markey (D., Mass.) And Richard Blumenthal (D., Conn.) In July, is pending.

A spokesman for the department’s National Road Traffic Safety Administration said he is researching whether driver monitoring systems are effective in identifying and reducing inattentive or disabled drivers.

The increasing availability of driver assistance systems has led to a mix of different features that vary by model and automaker, said Kelly Funkhouser, vehicle testing manager who leads automated vehicle coverage at Consumer Reports.

“All of these systems behave differently and there are no performance or design standards,” she said. “There needs to be more cohesion.”

Write to Mike Colias at [email protected]