I have neither of the above systems fitted to my vehicle, however, I found myself in a situation today which raised a few questions about them.

 

I was travelling along a single carriageway at approximately the posted speed limit of 50mph,  My carriageway was clear for in excess of 600 metres.  On the opposite carriageway, a Honda CRV decided to overtake the vehicle in front of him, and in order to complete the manouvre safely, he cut in on the vehicle.  I thought it necessary to reduce my speed slightly to ensure there was no collision.  When the CRV pulled back onto his carriageway, there was less than approximately 40 metres between our vehicles, and we passed each other in approximately 1.5 seconds. 

 

My question is this, if the CRV was fitted with ACC, and it determined that I was too close, would the system automatically brake whilst carryingou out the overtaking manaouvre?

 

If the same scenario was transplanted to a busy town centre, but reduce the distance between us down to 20 metres, would CB also apply in this situation?

 

Many thanks.

 

Fin

I have neither of the above systems fitted to my vehicle, however, I found myself in a situation today which raised a few questions about them.

 

I was travelling along a single carriageway at approximately the posted speed limit of 50mph,  My carriageway was clear for in excess of 600 metres.  On the opposite carriageway, a Honda CRV decided to overtake the vehicle in front of him, and in order to complete the manouvre safely, he cut in on the vehicle.  I thought it necessary to reduce my speed slightly to ensure there was no collision.  When the CRV pulled back onto his carriageway, there was less than approximately 40 metres between our vehicles, and we passed each other in approximately 1.5 seconds. 

 

My question is this, if the CRV was fitted with ACC, and it determined that I was too close, would the system automatically brake whilst carryingou out the overtaking manaouvre?

 

If the same scenario was transplanted to a busy town centre, but reduce the distance between us down to 20 metres, would CB also apply in this situation?

 

Many thanks.

 

Fin

 

Short answer - I don't know.   Hopefully, the ACC could distinguish between a vehicle travelling in the same direction (and maintain a safe gap) and one that was on-coming - but really no idea.   I would guess that, during an overtaking manoeuvre, the driver would have effectively overridden the ACC anyway, even if it had previously been engaged.

 

However, I recently had my own 'moment of doubt' about ACC.   My own car doesn't have it but I had the use of a Golf hire car that did have it (courtesy of Skoda Assist whilst my now ex-Rapid was being fixed under warranty).   I was trundling along in the nearside lane of the M3 and allowing the ACC to maintain the gap between me and the car in front.    Bloke in middle lane pulled sharply in front of me to exit onto a slip road.

 

Leaving aside that it wasn't a clever bit of driving, it was obvious what he was doing (he did have the courtesy to indicate left as he cut me up!) and, left to my own devices, I wouldn't have hit the brakes.   The ACC, which obviously didn't know what he was doing, applied the brakes quite firmly.   Woke me up, I can tell you...

 

Up until that point I'd thought that it was a great bit of kit and was wishing that my own car had it.   Now not so sure.

ACC is a great bit of kit, just takes a while to learn it's quirks.

Without going too deep into the ifs and buts of the OP's question, ACC can be overridden just by pressing the accelerator. So for any given situation you can prevent the system slamming on the brakes. Similarly, manually braking will cancel the ACC altogether

I've tried it on a couple of cars and it works really well, even braking to a complete stop at junctions. Which feels weird.

But I had a Lexus IS200T on test recently and twice the ACC decided it needed to brake, hard, for no apparent reason. Once was on an 80kph road with no cars ahead. It suddenly braked to 40kph. The woman driving a bit too close behind me got a surprise. The otehr was in a 50kph limit with two lances and I was doing about 45. I think it saw the car in the right-hand lane.

I never heard back from Lexus whether they found any faults.