General Motors' Super Cruise, the only hands-free driving system that's available on production vehicles, will add a couple of important new features for the 2022 model year: the ability to tow trailers and 100% automated passing when you come up on a slower vehicle.

The features will debut on the GMC Sierra light- and heavy-duty pickups. That makes the addition of hands-free driving while towing a particularly big deal.

Super Cruise, which combines sensors and an extremely precise map of limited access roads in the United States and Canada, has only been available in high-end Cadillacs till now. Only the Cadillac Escalade offers it for 2021. Adding it to segments like full-size pickups will make it available to a wider audience.

GM is adding Super Cruise to vehicles quickly, after a deliberate rollout that began with a single vehicle, the 2018 Cadillac CT6 sedan.

Super Cruise only works on roads covered by its detailed digital maps.

In addition to the Sierra, 2022 models of the Chevrolet Silverado full-size pickup: Cadillac CT4 and CT5 sport sedans, and GMC Hummer EV pickup will offer Super Cruise. It'll be on a total of 23 vehicles in the 2023 model year, including the upcoming Hummer SUV and Cadillac Lyriq electric vehicles.

Tesla's frequently touted "auto pilot" driver assistance feature is supposed to be used only with the driver's hands on the wheel, a fact frequently obscured by the automaker's claims and policy of testing potential updates on public roads in customers' personal vehicles.

Hands-free driving while towing

I tested both of the new features driving 2022 Sierras on a closed course at GM's proving grounds in Milford, Mich.

They worked as advertised, convincing me Super Cruise will reduce drivers' cognitive load on long trips, increasing safety and how far drivers can go before they tire.

When trailering, driver assistance features like sway control remain active. The system also adapts following distance and how brakes and acceleration are applied to reflect trailer weight. Towing capacity using Super Cruise will be less than the vehicle's total rated capacity, but GMC wouldn't say how much.

The system worked fine towing a 20-foot trailer weighing about 5,000 pounds around the proving ground's long high speed circuit.

Depending on how big a trailer or boat Super Cruise works with, it's easy to see pickup owners being delighted by the hands-free capability.

Totally automated passing

Automatic lane change, as GM calls the ability to pass slower vehicles on the highway with zero human intervention, is a major step that comes hot on the heels of a feature called lane change on demand that debuted in the 2021 Cadillac Escalade.

Automatic lane change allows the vehicle to check all around it for other vehicles and change lanes to go around slower vehicles ahead. It can adjust speed up or down slightly to create enough space to pull out from behind the laggard. The vehicle returns to its original lane when space is available.

The feature was quick and precise in repeated passes on GM's test track. Acceleration and steering inputs were so smooth that I didn't feel them as the Sierra changed speed and lanes.

I can't wait to test automatic lane change over a long drive on public highways. It's closed-track performance suggests it'll be a major improvement to a feature I've already found to be exceptionally effective in thousands of highway miles.

The new features will be available on Sierras in the first quarter of 2022.

Neither lane change on demand nor automatic lane change is available when towing a trailer because the trailer blocks some of the sensors necessary to make lane changes safe.

Super Cruise works on just over 200,000 miles of digitally mapped limited access roads in the U.S. and Canada. It's currently available ln the 2021 Cadillac Escalade and 2022 Chevrolet Bolt.