Tesla Motors Inc. plans to offer hands-free highway driving in its Model S electric sedans in 2015, putting it as much as a year ahead of other luxury brands in offering autopilot functions in automobiles, according to people familiar with the company’s plans, reported The Wall Street Journal.

Other auto makers, including General Motors Co. and Volkswagen AG’s Audi, have said they’re aiming to launch hands-free highway driving systems by roughly 2016. Daimler AG’s Mercedes-Benz now sells a system that can pilot a car on a freeway, but it is designed so that drivers must keep a hand on the wheel.

Tesla’s plan for rolling out a semiautonomous driving system, which it calls Autopilot, and several other safety and driver assistance capabilities, presents as much of a challenge to its rivals as any of the individual features, said analysts. Chief Executive Elon Musk sketched out some of the company’s plans in suburban Los Angeles Thursday night, but said little about timing.

Tesla is installing in new Model S sedans radar, cameras and other equipment to enable hands-free highway driving, an automated parking system and other driver assistance and safety features. To eventually activate certain convenience features, including hands-free highway driving, will require purchasing an optional $4,250 technology package, the company said on its website.

The company plans to upgrade the software in these cars through “over the air” updates to enable the features and functions over the coming months. Established car makers have been much slower to adopt the frequent, over-the-air software upgrade approach common in the world of cellphones and other digital devices.

“Tesla is able to bring forth enhancements in product through over-the-air updates that would take other auto companies years to commercialize,” Morgan Stanley analyst Adam Jonas wrote in a note on Friday.

On Tesla’s website, the company said “progressive software updates over time” will “ultimately” give the Model S Autopilot the ability to operate in automatic mode from highway on-ramp to off-ramp.

New Model S sedans shipping now will include some features already common in rivals’ luxury vehicles, including lane departure warning, which signals when the car is drifting out of its lane. Other driver assistance features such as a cruise-control system that can respond to traffic conditions are expected to be released this year.

More advanced autopilot features, including hands-free highway driving, an automatic lane-change function and the automated parking system should be delivered to cars by the first half of next year, the people said.

Tesla’s moves come as auto makers are racing to deliver features that allow the car to shoulder more of the tedium and stress of stop-and-go traffic and long highway drives.

Mercedes-Benz S Class and E Class models were the first to offer features that automatically keep a car centered in a lane, navigate freeway curves and maintain a set speed up to 124 miles an hour. The system uses stereo cameras, which mimic human eyes, radar and ultrasonic sensors to feed information about the car’s surroundings into onboard computers, but requires the driver to keep a hand on the wheel.

GM’s Cadillac division promises in 2016 a system it calls “super cruise” that allows hands-free operation of a car at highway speeds. Volkswagen’s Audi, BMW AG and other luxury brands also have signaled plans to offer hands-free “advanced driver assistance systems,” or automated driving features, around 2016.

As for parking, BMW and Lexus, among others, now offer parking assist systems that enable their newer vehicles to maneuver themselves into a parallel parking spot, but drivers have to remain on board. Mr. Musk is promising he wants his system to allow drivers to leave the car and let the vehicle park itself.

Mr. Musk’s promise of autopilot systems could spur rivals to speed up their plans to launch similar features, analysts said.

“The media attention…will likely accelerate the ADAS/semi-autonomous rollout efforts of other” auto makers, Barclays analyst Brian Johnson said in a research note.

On other features Mr. Musk highlighted, Tesla is a follower.

German luxury car makers already offer all-wheel-drive systems on most of their models, and about 36% of the vehicles they sold in the U.S. in 2013 are equipped with the systems, according to WardsAuto data cited by Barclays.

BMW’s i8 plug-in hybrid, which competes with the upper end of the Tesla Model S range, has a small gasoline engine that drives the rear wheels, and electric motor that drives the front wheels.

Tesla says its approach to all-wheel-drive is superior, because its system delivers faster acceleration than a standard Model S and has 10 miles additional driving range over a single-motor model. Most gasoline powered cars with all-wheel drive are less efficient than two-wheel drive models.