Some bigger news today, though anticipated for a few months, is Tesla's release of a highway cruise update for Model S cars from the last year.

Tesla's offering is not too different from what many other automakers have shown in what is sometimes called "highway cruise" -- a combination of lanekeeping and adaptive cruise control, both of which have been around for a while. The vehicle reportedly insists you keep your hands touching the wheel, but some owners report you can take them off. Of particular note is the addition of lane-changing, which you can do by flicking the turn signal. You must check behind you, since if you attempt this when the next lane is moving fast and somebody is coming up on you quickly, you could cause a real problem if you don't check. The vehicle won't do the lane change if its blind spot detector sees an adjacent car, but it won't stop you from cutting off somebody who is not in that zone and gaining on you.

I am curious about the claim that the system will "overtake" another car -- I have not tried it out yet, but I presume since it should not change lanes on its own, user input will be required to command driving around another car. While you can't safely make a lane change into a lane where you see no cars, you actually can make the change after passing a car because you know where that car is and that nothing is going to rush at you in the lane.

The release of this, and similar products will test a supposition I made earlier, that this products may not be as exciting as hoped. Worse, some drivers may find it a bit frightening trusting control to a vehicle knowing that from time to time they will need to grab the wheel. I have felt that myself driving in cars with adaptive cruise control, I am wondering if the ACC has seen the car stopped up ahead of me and will stop for it, since I see that before the radar or camera system does.

On the other hand, many people have reported that even though they must supervise, highway cruise can make the trip more relaxing, just as basic cruise control does. The trick is to get your brain into putting focus on its new sole task -- supervisor -- so that the rest of your brain can relax. With cruise control, you are reasonably able to have one part of your brain worry about steering, and relax the part that was going to worry about speed. So this may happen here.

More of a concern are the people who will trust it too much. Many of us already do crazy things, texting or playing with things on our phones when we are doing fully manual driving. It's a given this will happen here. It will be safer to take your eyes from the road for a longer period than you should in a manual car, but people may magnify that. Yes, if you take your eyes off the road and the car ahead of you stops suddenly, the car will very probably brake for you -- as will any car with forward collision avoidance. But not 100% of the time, and that's the rub if you trust it to.

I may have more to say after taking a ride in one of these. I think the first really interesting product won't be this, but a more full-auto traffic jam assist, that will drive for you in a traffic jam and allow you to take your attention off the road entirely to read or work on your phone or computer. At the low speeds of a traffic jam, boxed in by other cars, the driving problem is much simpler. You don't even need to see the lanes, just follow the cars. If the car in front of you zooms ahead, the traffic jam is over, and the driver needs to manually speed the car up. Done at low speeds, that transition can be fairly safe, and in addition, if the driver does nothing and the car slows to a halt, that is not unsafe -- just annoying -- in a breaking up traffic jam. The main remaining problem in traffic jams is what to do when the cars in front of you change lanes. Are they turning just to go into another lane, or is it because all the lanes are turning due to restriping (common in jams) or an obstacle. You need to get that right, and let the driver know about it, but you can't buzz the driver every time somebody does a lane change or the product is not useful.

Several car vendors (and probably Tesla) have been working on this, and could release it quite soon, if they get the guts and legal approval to do so.

Tesla may get more attention for the way they delivered these new features, as an over the air software update. Telsa has now done this several times, and promised it would do this, but from the viewpoint of traditional car makers, it is incredibly radical. In the modern computerized car, like the phone, regular software updates are just part of the system. This is going to be mostly positive, but will create some issues when the time comes for a "recall" of some electronic function of a car. Today when that happens, the car company mails all the owners and says, "Please come in to your dealer to get new firmware for your ECU to fix the problem." From that point, it is the owner's responsibility to get the update done. Tesla can send a fix over the air, but that means it can't pass responsibility on to the owners. Some day, a company is going to find a problem in their self-drive system that clearly should be fixed, but won't have the fix ready to go for weeks. It will face the question of what to do in those intervening weeks. Will it be forced to turn off the system it now knows to have a flaw? Or can it tell owners, "We know we have this flaw, if you want to drive, it's your responsibility now."