Abusing the TJA.

[siteguru]

I am not most people.
I am Ex Military.
And I seem to have a fully functioning car.

Now to be clear, I am agreeing to disagree.

 

[Loveclose]

My last twopennyworth on this thread - only because it seems folk can't agree which is fine. Everyone's experience is different.
1) Why use TJA as a substitute for ACC at 70mph cruising? To my mind, it wasn't designed for that. TJA was designed surely to help take away the labour when stuck in a crawling traffic jam. In my opinion, it does that really well.
2) LKA - huge disagreement here amongst us all!!! I haven't yet experienced a really jerky correctional move that puts my life in danger. I have had a correctional move where the steering wheel turns away from a left hand edge, but it hardly 'threw' me across the road, and certainly not in the path of any on-coming traffic. My reaction was to put an equal opposite force on the wheel to keep a balanced control. Not difficult.

I'm with the OP in as much as TJA works for what it was designed for. I wouldn't want that system working instead of ACC.

Irene has a lot to answer for in my very humble opinion. Clearly her fault to start with.....

 

[Bricktop X PWR]

Lovely Boy, Lovely Boy ?

 

[lsb777]

The LKA/TJA debate cruises on then I see.

I always switch LKA to Lane Departure Assist and have had no issues - yes it occasionally twitches the steering wheel but my Audi E-tron did that and unless you have spaghetti arms, it's not enough force to cause any dramatic issue (as I repeat, this is with Emergency Lane Keeping OFF).

I recently used TJA for well over 60% of a 600 mile round-trip and whilst it is a bit twitchy, it did a great job in helping relieve the boredom of motorway driving and did very well in it's main use of stop/start/roll in traffic jams.

Still can't find a way of getting the mythical Auto Lane Change to work though?!?

 

[Bricktop X PWR]

The LKA/TJA debate cruises on then I see.

I always switch LKA to Lane Departure Assist and have had no issues - yes it occasionally twitches the steering wheel but my Audi E-tron did that and unless you have spaghetti arms, it's not enough force to cause any dramatic issue (as I repeat, this is with Emergency Lane Keeping OFF).

I recently used TJA for well over 60% of a 600 mile round-trip and whilst it is a bit twitchy, it did a great job in helping relieve the boredom of motorway driving and did very well in it's main use of stop/start/roll in traffic jams.

Still can't find a way of getting the mythical Auto Lane Change to work though?!?

That's because it's bloody mythical!!!??

 

[Tight Git]

When I got my SE SR in November 2022 the LKA was truly dreadful and on unmarked country roads was really unpredictable and did have a tendency to pull fairly harshly left or right! I turned it off and it stayed off permanently until it was serviced last August. After the service LKA was much better but defaulted to on every journey and I turn it off for 90% of my driving.

Yes it's better than when launched but still has some way to go and will no doubt be continuously improved

 

[M101]

The commentators for MMA often say that when there's a knockout.

As to TJA = ACC + LKA ... no. TJA (Supposedly) tries* to keep you central in the lane, whereas LKA tries to keep you IN the lane.

* I don't like TJA either, nor LKA. I find TJA a bit twitchy, and whilst it works OK most of the time, sometimes it can get a mind of its own and try to steer me into a hazard. ?‍

whatever they are supposed to do, They dont do it well enough to be fitted to a car.

I am not most people.
I am Ex Military.
And I seem to have a fully functioning car.

Now to be clear, I am agreeing to disagree.

and being ex military is special because???

 

[OriginalBigAl]

Lovely Boy, Lovely Boy ?

I see Bricktop has a silent X power in camouflage green, Please please tell me he,s called it "Whispering Grass".

 

[Bricktop X PWR]

I see Bricktop has a silent X power in camouflage green, Please please tell me he,s called it "Whispering Grass".

Bloody Outstanding!!!??????

 

[NickHeynes]

My problem with TJA is that it gets to close the the white line on my near side.
I commute a long the A13 into London and the sheer number of bikers filtering through between the the outside 2 of the three lanes can be terrifying!

I try to leave as much space as I can but TJA seems to want to prevent this so I tend not to use it .

 

[Bricktop X PWR]

My problem with TJA is that it gets to close the the white line on my near side.
I commute a long the A13 into London and the sheer number of bikers filtering through between the the outside 2 of the three lanes can be terrifying!

I try to leave as much space as I can but TJA seems to want to prevent this so I tend not to use it .

I suspect in the future we will be able to alter the distance to the center line in the same way you can select the distance to the car in front.


Maybe.

 

[grog]

I use TJA on the school run. Other than the annoying fighting the steering wheel on occasion the biggest problem I have is that every so often when stopping the car on a slight incline doesn't do a full stop and starts rolling backwards - like the old days when people couldn't do a hill start!

But I do like the fact that mostly you don't have to endure the monotony of accelerating / braking ever 30 seconds.

 

[NLMGSAN]

I use TJA on the school run. Other than the annoying fighting the steering wheel on occasion the biggest problem I have is that every so often when stopping the car on a slight incline doesn't do a full stop and starts rolling backwards - like the old days when people couldn't do a hill start!

But I do like the fact that mostly you don't have to endure the monotony of accelerating / braking ever 30 seconds.

If you do not like the annoying fighting you can stick to the slowest speed with ACC. No more jerking on the wheel.

 

[Bricktop X PWR]

I'm getting hellish tempted to go for a motorway spin just to try this out now.

@Rolfe It's been some months since that post.
Did you ever manage to have a try of the TJA at speed?

Note: Anyone just seeing this and not reading the whole thread.......

TJA was designed for traffic jams and slow moving traffic, however, it can be used for higher speeds.


TO BE CLEAR, I WASN'T USING IT FOR THE PURPOSE THAT IT WAS DESIGNED, NAMELY TRAFFIC JAMS AND SLOWER CRAWLING TRAFFIC

Not shouting! Just emphasising the point before an inevitable post telling me that it wasn't designed for higher speeds!!!!?

 

[lsb777]

I always use TJA on long motorways. Twitches a little to keep in lane but absolutely no pulling to one side etc. Takes away some of the monotony of the drive.

 

[blue2]

Not tried TJA yet but not sure I would in an actual jam, maybe i am a bit germanic in my road manners, although the idea of the car keeping in its lane at higher speeds is much more tempting. But then again just realised I live in the UK where a 70mph open lane for more than 2 miles is a dream.

 

[decrep]

Lucky I guess, our "freeway" can get a bit crowded, but rarely a real jam. If I leave a sufficient gap to the car in front, I can adjust my speed to the average and not have to break or accelerate too much. So I haven't tried TJA.
But neither of us like the MG LKA, we both turn it off at start up.
I have it on another car and it's smooth and gentle. I can live with that unless on unmarked country roads, where it can try and throw you off into the gravel.
That's something you don't want to happen unexpectedly. The gravel here is like marbles, not quite as slippery as ice, but you can get in real trouble if you try to swerve back on to the road.

 

[wattmatters]

I did a test of the TJA system on a section of the Pacific motorway near me. No traffic, dual lane 110 km/h. It steered OK but is a little jerky, constantly making adjustments when it's not really required. It needs more subtlety with the steering adjustments. My car is from Sept 2023 and no software updates since, so no idea if later versions provide a more refined steering experience. I wasn't relaxing because of the car's constant changes in lateral motion.

 

[Bricktop X PWR]

I'm on R46 and there were improvements to the ACC.
More distance to the car in front and no slowing of the vehicle in the bends.

I can't emphasise enough that TJA is not designed for high speed and if you do use it for that, then you need to have your wits about you.

 

[tonybridge]

I'm on R46 and there were improvements to the ACC.
More distance to the car in front and no slowing of the vehicle in the bends.

I can't emphasise enough that TJA is not designed for high speed and if you do use it for that, then you need to have your wits about you.

Bricktop, I know you keep emphasising that TJA is not meant for motorway driving, and I don't get why anyone would do it. It seems to me that you would need to absolutely monitor it every second - so why not just turn it off and drive as normal? However, I find that on the motorway, ACC is fantastic - I steer as normal, letting the ACC take over should I look in my mirrors just as the car in front hits the brakes