As I was the one starting this thread some 6 months ago, and I finally have my car, here is my view on TJA after having used it for a week in some major traffic jams in the most congested city in the world (according to Forbes) Brussels:
No pictures, as they would be the same as those posted earlier in this tread.
-TJA will only work on freeways. It will give you a warning when you start it up, and it's obvious it uses the navigation data to determine if it is on a freeway or not.
-As soon as you go below 40 km/h , cruise control and TJA is on, and you have a hand on the steering wheel, it will switch on. I did have a few cases where it took a few seconds before actually switching on. I guess it has to do with the camera being able to interpret the lines on the road. so if you are too close to the car in front of you when you switch it on, it will not work.
-The steering wheel becomes hard to turn. So there is a physical indication that it is on, besides the symbol on the HUD or in your dashboard.
-If you manually override the system to turn the steering wheel, it will accept minor changes, but switch off if you try too hard.
-Once traffic get's going again, and you reach 40 km/h, the cruise control will keep the car at 40 km/h and give you a visual warning that you can go faster. Touch the gas pedal, and the TJA switches off, and the car accelerates to the speed set in the cruise control.
-Once TJA is on, I did not have to keep my hands on the steering wheel ! Strange, because the manual says you have to. I tried it for over 15 minutes without touching and it never switched off...That's when I fell asleep so I don't know what happened after
-It keeps the middle of the lane very neatly, and you do see the steering wheel making the corrections by itself.
-On sharper turns (exit ramps, bends in the freeway) the system tends to go towards the outside of the turn. It stays in the lane but comes dangerously close to the outside line of the lane. If you have a truck next to you, it is very hard to resist correcting yourself.
-On wet roads in the dark it doesn't work (the reflection of the road makes it hard to distinguish the lines)
-What I find annoying is that when the car stops, you have to touch the gas pedal to get going again when traffic in front of you moves. Has nothing to do with the TJA, but is a feature of the cruise control. I understand the need for this safety measure (imagine you get out of the car and suddenly it leaves without you ! ), but it is still annoying. They could have used the sensors in the driver seat or something else to ensure you are still there...
Overall it is a great system, but only useful if you spent a lot of time in traffic jams like I do.
One word of warning: the car becomes so automated, and because you very quickly become accustomed to that, it has an inherent danger that you trust the system too much. Imagine being in those same traffic jams, and you trust that ACC Stop & Go and TJA will do it for you...but you forgot to switch it on ?
Some added features for the fully automated car would be nice:
-Get into you car, enter destination "HOME" , and the system sends a text message to your partner saying at which you time will be home
-Enter "GIRLFRIEND" as destination, and it sends a text message to your wife saying you will be late due to a meeting ...
-Automatic horn whenever someone in front of you does stupid things
-Cruise control that adapts your speed to the speed limits of the road (with the option to add yourself an extra margin ... in both directions)
-As soon as the TJA and cruise control take over, your favourite TV series or movie shows on the HUD...or even better yet, your PC screen so you can work (need to find a solution for the keyboard popping out of the steering wheel )
Cheers