I seem to somehow have become a geek on how to get around with a Tesla. There are boatload of real experts at Tesla Motors Club, so here is a quick summary of some of things that I've learned.
On Using Autopilot, pay attention on the first drive
There is so much written on this that I can't help but write down a bit about how I use the thing after some experimentation over the last year or so. This self-driving stuff is definitely complicated and certainly isn't perfect, but at least for me, it has significantly reduced driver fatigue.
The first thing to know is that you really want to use it where the lane markers are super clear. There are routes where we live where the Highway department does an incredible job making sure the striping is accurate and places where there is construction and really confusing. Safety is all about margin of error.
So the first rule is that when you first use it on an new road, really drive the car, while Autopilot is engaged.
Now what does paying attention really mean?
Well, for me at least, it means, holding the steering wheel firmly enough and keeping the eye focused enough that you are really driving the car. The Autopilot will move the wheel as well and you are sort of "fighting/dancing" with the controls, the point is that if Autopilot makes a mistake, you just grip the wheel hard and it disengages. I find that most of the time when it makes a mistake, it will turn in the wrong direction so just make sure to tighten your grip. It should take 250 ms to do that.
The main thing is to think of it as your "nanny", you both want to be driving a car. (Theoretically at least, that should reduce chance of accidents by quite a bit because, it would take both you and Autopilot to make a mistake).
Ok now that we have covered the first experience, what do you do when you have been driving frequently, well there are really two cases where Autopilot really helps. The first is stop and go driving. This stuff really works well in that case. And I find driver fatigue really falls. When I do an hour of bumper to bumper (yes, where we live that's not uncommon), then having the Autopilot set of eyes on the front really works.
The second case is in freeway driving on straightaways. Keep following the drive with Autopilot along for the ride rule and it is pretty easy to keep pace and also to have turns work.
Do not set the speed to 75 and forget it...
It is really tempting with their Traffic aware cruise control to set the thing to 30 mph over the current speed (like you are stuck in 15mph traffic, it slows down, but you leave the cruise control at 75). The problem here is that if the system glitches and doesn't see a car ahead of you, like it takes an off ramp, then suddenly the car will obedient accelerate like crazy. This can get you into real trouble because these Electric cars are fast. So as you drive, and speed and slow up, make sure that your cruise control is set to a speed you wouldn't mind being in, if the thing makes a mistake. And also set "CHILL" mode to reduce the rate and maximum acceleration
There is nothing more disconcerting that sudden acceleration because unlike having the steering wheel firmly in hand, it does take more time to hit the brakes. And in cars with instant torque and which do 0-60 in 4.4 seconds that's a problem.
Make sure it sees the lanes, two blue lines are your friend
If the car only sees one side of the lane, then it is guessing where the other side is, this isn't a great idea, so when you are driving make sure that the lane markers are solid blue on both sides of the car.
That let's you know the driving is really working. There are times particularly on smaller streets where the side markers disappear. If that happens, you can leave it engaged, but make sure your alertness mode is set to high because there might be an obstacle on the "unseen side."
And when you are switching lanes see if there are additional Grey lines on the outer edges. This means it sees your lane markers and the lane lines to the left and right. This is an additional margin of safety because when you switch lanes it you know it will be properly in the next lane.
In the 2018.12 release, it is quite good at lane keeping and also lane changing, but there are times when you hit the turn signal and the car refuses to change lanes. It is seeing something that you are not, like a car in your blindspot, but I've found it is quite conservative on lane changing. So to tell if it will change, when this happens, I check the back and make sure the rear camera is on (more redundancy) and then hit the turn signal again to make it lane change.
For me at least this happens most often if you are switching in a multilane freeway. If there is a truck two lanes over it will not change. Also this is the one case where with 2018.12, if it sees a car in your blind spot it will throw a car icon there.
At least for me, I usual cancel the turn signal too soon, leave the turn signal engaged until you are fully in the new lane. Otherwise, it may interpret that as an emergency abort because you saw something and very abruptly shift into your old lane.
When should you really make sure it is engaged? Weather
In a word when visibility is poor. If it is dark and raining, having that radar in front and an extra set of eyes is pretty invaluable. Even if you are worried about accidents, follow the you are driving and Autopilot is helping rule and it does seem to be much safer. The Autopilot seems very good at seeing the car ahead of you, but make sure by looking at the icons (at least on Model X and S) to make sure it is really tracking a "car" ahead of you.
What are the current gotchas?
This is completely unscientific but driving always seems to involve exceptional events, here are the ones that have happened to me (at least as of the 2018.12 release):
A bicycle, a truck, they are all cars, so when you see something crossing, glance down to make sure your car sees it too. For instance, if a car is at an unusual angle (like when someone abruptly crossed in front of me with zero room to spare, the front camera may not see it as a car until too late, so beware that there are still really dangerous folks on the road and people will come at you literally from all directions.
It can "false positive" an obstacle and then hit the brakes, So just be aware that there can be sudden braking, so don't prop your feet up on the console or anything. You may have to hit the accelerator as well as the brake when driving.
Also be careful where the road folks have put a painted low concrete barrier on the road, if the Tesla thinks the outside of that barrier is the lane edge, then you can hit the thing. I actually curse the people who think this is a "low barrier with paint" is a idea because when it is dark and raining here, you lose perspective and it is hard to tell if that 3" curb they magically put in the median is there or not. You just see the bright yellow and can't see that it is tall. Autopilot can get equally confused. Again, drive the car is the main thing.
Disengagement magic near pedal
Finally at least on my model x there is some sort of sensor down by the pedal. If I in TACC mode, then putting your foot near the brake can cause disengagement. So be careful about lounging too much.
Driving setting reset
Finally gotcha is that at least for me occasionally the driving setting change. Lane change turns off or warnings turn off so if Lane changing isn't working wander over to the Settings tab and look at your driving setting to make sure they haven't moved 🙂