2019 Model Radar Cruise Safety Issue

[roadster-rav]

There is one aspect of the radar cruise control which to me verges on being dangerous. Namely the effect of indicating right in order to make a lane change /overtake. My usual method would be to signal before any intended manoeuvre by about three indicator clicks or more. The purpose being that if another vehicle intends to do the same thing from behind you or for example a motorcycle is closing very quickly in the outside lane they have time to react. But when radar cruise control is active and your current speed is below the target setting because you are following another slower vehicle hitting the right indicator causes an immediate, very immediate, surge of acceleration and seems to instantly ignore your proximity to the vehicle ahead as though it has disappeared. This results in closing dangerously and quickly on the back of that vehicle and leaves no choice but to change lane violently or hit the brakes to restore a safe distance. Surely an automated feature which leads to implicitly unsafe driving is very bad and in my opinion this is so dangerous that I am contemplating how I might bring it to the attention of the appropriate safety authority

[FROSTYBALLS]

If you wish to report this as a possible safety issue, see the following guidance - https://www.gov.uk/vehicle-recalls-and-faults

If there are sufficient numbers of similar reports, DVSA will investigate the possible issue with the manufacturer. If there are insufficient numbers of similar reports, DVSA will come back to you.

[bewA]

Are you saying as soon as you indicate right the car moves out itself and then accelerates to go up to the set speed?

I have a 2019 Corolla and i doubt the system is actually any different between that and the new rav4.  I have noticed a similar behaviour with my Corolla once of twice but i'm aware that it behaves in that fashion so adjust my driving to suit.  Thinking about how the system works, it's following a car and you indicate right and move out there is no car in front any more so the car accelerates to the set speed.  Depending on the difference in the current speed and set speed it may determine the severity of the acceleration subject to a vehicle being detected.

Toyota could argue that the system is not supposed to be used in an overtaking situation because of this surging behaviour and I would be inclined to agree and it's the drivers responsibility to be fully aware of the surroundings and the behaviours/capabilities of the car.

 

[Alan1234]

Surely the car should not increase speed until you have cleared the car in front then it will pick up any other car and hold you at the correct distance .

 

[PeteB]

I must admit I was a bit bewildered when I read this post as in over 4,600 miles I'd not experienced this, and neither had I in my Gen 4 Prius in which I'd done 40,000 miles in 3 years (of course, the ACC in the Prius was part of Safety Sense 1, so that element may have been different in the Prius - there are certainly a number of other changes in operation compared to the Prius).

However, today I got the chance to do a quick experiment on a single carriage A road with a 60 mph speed limit.  My ACC was set to 60, just one car in front which I was following at about 50.  As there was nothing following I flicked the indicator stalk to the right so it started the triple flash, and sure enough the car started accelerating towards the car in front.

[SI: - no, the car doesn't steer itself to overtake (like a Tesla would), although if it's in a mode where the Lane Keep Assist is following the car in front (dotted line on the ACC display) rather than within the lane lines my understanding is it would try to follow the car in front if it went into a slip road to the left or changed lanes to overtake.]

However, in my case it wasn't dramatic because I was in ECO mode, and the ACC accelerates very gently in this mode, so I had no trouble cancelling the ACC.

I guess the reason I haven't encountered it is because:

1. In ECO mode I'd barely notice it
    
2. I generally let the car follow the car in front and if it's only 5-10 mph below my set speed I don't usually try to overtake
    
3. If it gets much slower, I usually wait until the road is fairly clear of other traffic and then overtake - if there's nothing behind me, I don't bother to signal until I start to pull out
    
4. I frequently cancel ACC if I'm about to overtake

I'm guessing acer is either in Normal or Sport mode, which will give significantly more rapid acceleration, especially in Sport mode.  I'm grateful to acer for making me aware of it though and will add it to the things I consider when starting an overtake, but I'm not sure (for my driving style) I'm as worried as acer is.

 

[IanML]

This sounds like highly undesirable behaviour, and I suggest you report it to Toyota UK, mentioning that you are minded to report it to DVSA.  Let us know the result.

[roadster-rav]

Grateful to Peter B for testing and confirming this behaviour. I will go ahead and report to DVSA as suggested by Frostyballs. If anyone else would like to test and report it would be most welcome.

[Buff69]

You could look at it this way, when you overtake the car in front, you would accelerate with the foot pedal, so what the car is doing is overtaking with the indicator, after all that is what cruse control is all about not having to use the foot pedals you look in the mirror look over your shoulder if it’s clear to go you indicate and the car does the rest that’s my take on it   

[roadster-rav]

7 hours ago, Buff69 said:

You could look at it this way, when you overtake the car in front, you would accelerate with the foot pedal, so what the car is doing is overtaking with the indicator, after all that is what cruse control is all about not having to use the foot pedals you look in the mirror look over your shoulder if it’s clear to go you indicate and the car does the rest that’s my take on it   

Yes but the purpose of indicating is to alert other road users to what you are intending to do, not what you have already started to do.

[warrenboswell]

Not the case on the previous model. When I indicate (3 clicks) I have to pull into the lane before the car accelerates

[MrNuts]

i've a VW Tiguan with adaptive cruise and it does this as well, i find it perfectly fine, as the car slows i indicate and it maintains the speed, you do get used to it, i've done 89,000 miles in the tiguan on mostly motorway miles. When i test drove the RAV i didn't find this an issue.

 

On the VW you can adjust the response of the cruise, eco,std, sport. Maybe look at that.

[Catlover]

It is the drivers decision to actuate radar cruise control thereby use it responsible. He/she knows that when radar cc is set the vehicle will automatically slow down if the vehicle in front slows down, speed up if the vehicle in front speeds up (up to a limit set by the driver). And of course the driver ALWAYS needs to be alert and in control of the vehicle, and that includes being in control of any aids the vehicle may have. 

So, we now talking about the situation where the driver makes a decision to overtake the vehicle in front. Inevitable that means the vehicle speed has to be increased, and that increase in speed has to be under the full control of the driver, after all it is potentially a dangerous action if not executed correctly. 

Whilst radar cc is activated, a following decision by the driver to overtake means that the requirement for radar cc is negated, thus the driver needs to deactivate the radar cc so the driver is in full control of the vehicle to execute the move. So it is my opinion the driver needs to cancel radar cruise control when wanting to overtake.

Lets face it, Acer, and others, may be writing to the DVSA but action, if any, may take some time to implement, during which time they, and others, will be driving their vehicles fitted with radar cc.  So, I want to ask those persons to indicate what they would do out on the road knowing what action their car, fitted with radar cc, may do if the driver was to set the radar cc device and then at sometime decide to overtake a slower vehicle?

[Catlover]

Thanks bewA (Si) for the “like”. I just read your earlier comment and seen my conclusion is same as yours...... the driver has the responsibility of being in control of the car.

[Devon Aygo]

All personal opinion but why indicate before you ensured the maneuver is safe, I recently came across someone doing this on a motorway, where they indicated regardless of approaching traffic then realised they could/would not maneuver and cancelled the signal unfortunately the improper indication caused the driver in front to brake sharply anticipating a car pulling out and very nearly causing an accident both I and the driver in front dropped back and took a deep breath only to witness the same thing again, a car approaching then braking because the same driver had again indicated, then cancelled because they clearly had not checked the way was clear before indicating.

IMHO you look, ensure you are safe/confident you can maneuver then indicate and maneuver this would negate the radar cruise "issue" as you would not have to cancel the maneuver in the first place.

[IanML]

I have to disagree.  The decision to accelerate is for the driver to make, and he should operate the accelerator to do it.  The CC should ignore the trafficator, which is simply an indication of intent, not a command.

Yes, you can mitigate the issue by drill, BUT YOU SHOULD NOT HAVE TO DO SO.  The design is plumb WRONG.

[Buff69]

IanML I don’t think cc is for you 

[Catlover]

I not a particular fan of the cruise control aid, I suppose it does have its uses. It’s purpose is to keep a constant speed, thinking for the driver, as once you set it the system tries to keep a constant speed...... it increases engine power to maintain a speed going up a slope, and you can feel the engine holding back coming down a slope. Radar cc takes the aid to a different level, slowing your vehicle down if the vehicle in front slows down, increasing speed up to the driver chosen max if the vehicle in front speeds up after travelling slower for whatever reason.  However, it is my opinion, that if the driver decides to overtake the vehicle in front that is no longer requiring the use of the cruise control, and therefore, in order to execute the overtake safely the driver has to take full control of the vehicle and thus turn off aids that might interfere with safety ie turn off radar cc before the process of overtaking begins. 

Irrespective of what driving aids are purchased and used by the buyer of a vehicle, the driver must always be in control of the vehicle. The days of driverless vehicles have not yet arrived. 

[Buff69]

Catlover, I totally agree with you, they are driver AIDS not replacement for the driver, all you have to do is slightly press on the brake pedal, not to slow down but to disengage the cc then make your move and press button to engage back the cc. If it worries you then you don’t use it (like my wife). Me I have used it driving artic’s and cars and I think it’s a great help, but wouldn’t make anyone use it if they don’t want to, “it’s each to there own” like marmite lol 😂 which I like to. I still think it’s a good thing having the motor increase speed by using the indicator buts that’s me.

[Scottydog007]

I have no issue with this and do not see a problem. At the end of the day it is down to us to use our initiative and not to get too reliant on things. This is probably why the Boeing 737 Max crashed so much, inexperienced pilots not overriding auto controls.

This radar cruise control originated in America premonitory for the Winnebagoes that would follow each other on straight long loads. I really do not believe it suits our type of motorways and I find it dangerous. I set it to normal cruise control which forces me to stay awake and forces me to give some input occasionally.

[PeteB]

This is on P350 of (my copy) of the manual:

"When the turn signal lever is operated and your vehicle moves to a left lane (lefthand drive vehicles) or right lane (right-hand drive vehicles) while driving at 80 km/h (50 mph) or more, the vehicle will quickly accelerate to help to overtake a passing vehicle."

I must admit, I hadn't noticed it before, even though I'd read through the manual twice (but it does total over 1,000 pages!).  Also, as I said above, because of the way I have set my car up and the way I use ACC, I hadn't actually come across this feature until I did a couple of experiments having read the OP's post.

This is at odds with what acer reported and I found out in that the car starts accelerating once the indicator is used even without changing lanes, and while the car in front is in the way.  In my case, because I almost always use ECO mode, the acceleration is far from "quick".  Also, at speed I always have the separation set to maximum.

I tried to do another experiment last night (whilst being very careful to do it safely) - I selected Sport mode and followed a vehicle doing about 55 in a 70 limit, with my set speed also being 70.   Unfortunately, I only got one chance to use the indicator without risking confusing anyone (i.e. there was no one in view behind or alongside) but by this time the vehicle in front had increased speed to only 6-7 mph below my set speed, so the acceleration was still not brisk by any means.

However, it did show me that (in this situation at least) after briefly accelerating the system remained aware of the car in front and dropped back without actually getting too close.  I'll try that again if I get another opportunity to do it with no risk of confusing other road users, but while I'm prepared to try it in Sport and/or Normal modes, I will not use anything less than the maximum separation setting.

[OT re the reference to the 757 Max above, it didn't help that no pilots had even been made aware the new anti-stall system existed until after the first crash, one of the two airlines didn't yet have a Max simulator, and the other had one but it was not equipped with this system.  The pilots in the second crash appeared to have done everything they should (as far as possible in the time available and under the pressure they no doubt were under), but as I understand the current analysis they couldn't manually move the control to cancel the trim adjustment fast enough, and by turning systems on the allow them to do it with electronic controls the plane started trying to dive again.  Given how little time they had been in the air and how little altitude they had, there wasn't much time to think through their other options, if indeed they had any.]

 

[IanML]

14 hours ago, Buff69 said:

IanML I don’t think cc is for you 

On the contrary, If my car had radar CC and the situation called for it, I would be very pleased to use it, provided the autonomous acceleration function were disabled.  I think it should be an option to disable it, using either one of the "hokey-cokey" methods, or maybe with Techstream.

[Alan1234]

Don't worry we will all be in driverless cars zooming around and you can stick your kiddie play steering wheel on the dash and scream !Removed! car has a mind of its own as your missus rolls her eyes muttering silly old fool .😂

[Alan1234]

[bewA]

#shotsfired [emoji23]

[Rav Rob]

I was surprised when I discovered this feature, but now used to it and love it, one less thing to do when overtaking. As long as your at least 2 at the 2 bar cruise distance there is time for it 2 indicate for a while and then for you to move over without getting too close to the car infront, the RAV is sprightly but its not a Ferrari! - It could be a problem if you were at the short 1 bar gap.

When its very busy I often sit in with the HGV's and use the CC and lane keep very effectively to reduce fatigue, sometimes you come up on a much slower truck, flick the indicator, a couple of flashes the car is picking up speed meanwhile more suited to the lane your joining, pull out, overtakes quickly so you don't get rear-ended, pull in, the car closes up on the next truck ahead and slows to match it. So easy, flick on the indicator and a couple of steering flicks. Love it!

What IS a bit dodgy is if the radar is tracking a vehicle in front and you come up to a roundabout at the end of a dual carriageway, the car in front slow or stops briefly, so do you by radar, the infront car pulls out briskly as something is coming round the roundabout, then so will the RAV pull out automatically and collide! (if you forgot to disengage radar CC)