2019 Model Radar Cruise Safety Issue

[IanML]

12 hours ago, Rav Rob said:

...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)

Ouch 🤯🤯

How will they fix that with self-driving cars, I wonder?

[roadster-rav]

13 hours ago, Rav Rob said:

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)

No they have thought of this. In order to roll again you must either press the accelerator or press +RES. So far I haven't had the nerve to try this and in that sort of situation I think I would have hit the brakes and disengaged cruise control long before coming to a stop. I also don't find the automatic speed reduction very smooth but that's probably because it takes you by surprise when the brakes come on. These systems only look at the one vehicle ahead so they don't anticipate a slowing queue that the driver can see and react to more gently. I don't know how/if the parking brake hold function works in this situation.

[PeteB]

2 hours ago, IanML said:

How will they fix that with self-driving cars, I wonder?

They have a lot more cameras, sensors and radar features than our Toyotas:

For a few years, Teslas for example with the additional autopilot upgrade come with 8 cameras facing all directions, in addition to all the other features.

Many of the test cars being tested at the moment have roof mounted spinning lasers that build a very accurate 3D 'picture' of the car's surrounding environments.

Plus they are continually 'learning' and if a fault is discovered in one (such as a Lexus RX that pulled out a little too close in front of a bus a few years ago and had a minor collision because it had learned that cars slow down but didn't know busses may not!) then all cars with the system can be updated to learn not to do it again - as opposed to human drivers where each has to learn separately from his/her own mistakes.

[PeteB]

24 minutes ago, roadster-rav said:

No they have thought of this. In order to roll again you must either press the accelerator or press +RES...

...I don't know how/if the parking brake hold function works in this situation.

Not necessarily: if the car in front moves off within 3-4 sec, your (and my) car will follow without needing to prompt it.  I find it quite handy in slow moving queues, but you can't afford to take your eye off the ball!

The 'hold' feature will stay stopped until you press the accelerator, but after about 3 minutes it will cancel and gives a warning (I think the car goes into park - without the level moving, obviously), but normally by this time I will have selected P myself if things aren't moving.

[Rav Rob]

6 hours ago, PeteB said:

Not necessarily: if the car in front moves off within 3-4 sec, your (and my) car will follow without needing to prompt it.  I find it quite handy in slow moving queues, but you can't afford to take your eye off the ball!

The 'hold' feature will stay stopped until you press the accelerator, but after about 3 minutes it will cancel and gives a warning (I think the car goes into park - without the level moving, obviously), but normally by this time I will have selected P myself if things aren't moving.

Exactly! its quite a few seconds it will stop and it will still pull away itself without you needing to do anything. Like you, I find its great in slow rolling traffic that often stop momentarily but is a bit unnerving at times I must admit.  But I remind myself that I have seen endless shunts in these conditions due to lapses of concentration over the years. The car's computer does not have any such problems, its 100% concentrating 100% of the time, so is probably safer doing it than I am!

And yes you could follow a car up to a roundabout that doesn't stop just slows right up and then zooms out into a gap, the RAV would faithfully follow it and pull away into the side or path of whatever is coming round the roundabout.