Living with a Jazz Crosstar

[John Ratsey]

I forget if I've previously mentioned that the speed sign recognition system hasn't fixed the problem of wrongly detecting signs on branching roads such as those passed when going round a roundabout. I would have thought it could exclude such signs by either figuring out that the vehicle didn't pass between them or by taking account of the direction that the front wheels are pointing. There are times when using the speed limiter based on the signs would be useful but not when there's going to be a conflict between driver and vehicle over the correct speed. A vehicle wanting to travel at 20mph on a 40mph road is going to be annoying.

[culzean]

I forget if I've previously mentioned that the speed sign recognition system hasn't fixed the problem of wrongly detecting signs on branching roads such as those passed when going round a roundabout. I would have thought it could exclude such signs by either figuring out that the vehicle didn't pass between them or by taking account of the direction that the front wheels are pointing. There are times when using the speed limiter based on the signs would be useful but not when there's going to be a conflict between driver and vehicle over the correct speed. A vehicle wanting to travel at 20mph on a 40mph road is going to be annoying.

Notice how quiet it has gone on autonomous vehicles ( I haven't seen any 'amazing breakthroughs' or hype for almost 2 years now,  when before that the news was full of how clever they were, how accidents were a thing of the past caused by stupid humans,  all we really saw was vehicles going round tracks at <20mph and hitting barriers ) - they have realised that replacing humans ain't easy,  the situation you experience with the auto speed recognition is so easy for humans we don't even think about it, but for a machine it is almost impossible. That is just a small fraction of the problems you run into when you look to replace human judgement with machine AI. A five year old has better judgement and motor controls than any autonomous car may ever have.  We take so many things into consideration when making judgements,  a lot of them very nuanced, such as is a driver looking at us and their body language ( the bit we can see anyway ).   

[robark]

I forget if I've previously mentioned that the speed sign recognition system hasn't fixed the problem of wrongly detecting signs on branching roads such as those passed when going round a roundabout. I would have thought it could exclude such signs by either figuring out that the vehicle didn't pass between them or by taking account of the direction that the front wheels are pointing. There are times when using the speed limiter based on the signs would be useful but not when there's going to be a conflict between driver and vehicle over the correct speed. A vehicle wanting to travel at 20mph on a 40mph road is going to be annoying.

I am disappointed to hear that the misreading of speed limits, by wrongly reading those on a side road, has not yet been fixed by Honda. It is one of the reasons why I kept my 3rd generation Jazz for less than 2years. A feature that is supposed to be safety measure can is a hazard when you are back ended in a 30 mph zone because your car has just read a 20 mph limit on a side road!

[equaliser]

I forget if I've previously mentioned that the speed sign recognition system hasn't fixed the problem of wrongly detecting signs on branching roads such as those passed when going round a roundabout. I would have thought it could exclude such signs by either figuring out that the vehicle didn't pass between them or by taking account of the direction that the front wheels are pointing. There are times when using the speed limiter based on the signs would be useful but not when there's going to be a conflict between driver and vehicle over the correct speed. A vehicle wanting to travel at 20mph on a 40mph road is going to be annoying.

I am disappointed to hear that the misreading of speed limits, by wrongly reading those on a side road, has not yet been fixed by Honda. It is one of the reasons why I kept my 3rd generation Jazz for less than 2years. A feature that is supposed to be safety measure can is a hazard when you are back ended in a 30 mph zone because your car has just read a 20 mph limit on a side road!

None of the manufacturers have a reliable traffic recognition system, it's not just Honda who like the rest of the manufacturers buy the system from a third party. An immature technology limitation I'm afraid.

[ColinS]

A feature that is supposed to be safety measure can is a hazard when you are back ended in a 30 mph zone because your car has just read a 20 mph limit on a side road!

Admittedly it has its shortcomings but is is hardly a hazard.  It doesn't apply the brakes for you, it merely beeps to warn you that it thinks you are over the limit and it stops you accelerating so it will gradually reduce to the speed it detects unless you take action.  I'm sure you have many times approached a car going slower that you without back ending it.

The most annoying feature is that it fails to read signs in harsh sunlight.

As I have said many times before, this and other "safety" features are "aids" and you are not mandated to use them.  You are in control of the car and it is up to you to drive safely and within the law, as any magistrate will be quick to tell you.

[culzean]

I forget if I've previously mentioned that the speed sign recognition system hasn't fixed the problem of wrongly detecting signs on branching roads such as those passed when going round a roundabout. I would have thought it could exclude such signs by either figuring out that the vehicle didn't pass between them or by taking account of the direction that the front wheels are pointing. There are times when using the speed limiter based on the signs would be useful but not when there's going to be a conflict between driver and vehicle over the correct speed. A vehicle wanting to travel at 20mph on a 40mph road is going to be annoying.

I am disappointed to hear that the misreading of speed limits, by wrongly reading those on a side road, has not yet been fixed by Honda. It is one of the reasons why I kept my 3rd generation Jazz for less than 2years. A feature that is supposed to be safety measure can is a hazard when you are back ended in a 30 mph zone because your car has just read a 20 mph limit on a side road!

I have seen tales of the cameras ( not just Honda ) seeing ESSO signs and slowing down, ( taking them for 50 limit ) - cameras cannot interpret what they see as well as humans and if a roadsign is picked up by camera it just accepts it,  size could be a thing but around our way speed limit signs don't seem to be a fixed size and small ones turn up in some areas - some are round,  some are round on a square background etc.... as humans we just accept it without a second thought and even if they were on their side or upside down we would still easily understand it...

[ColinS]

I have seen tales of the cameras ( not just Honda ) seeing ESSO signs and slowing down, ( taking them for 50 limit ) - cameras cannot interpret what they see as well as humans and if a roadsign is picked up by camera it just accepts it,  size could be a thing but around our way speed limit signs don't seem to be a fixed size and small ones turn up in some areas - some are round,  some are round on a square background etc.... as humans we just accept it without a second thought and even if they were on their side or upside down we would still easily understand it...

And if you manage to write software to cater for every eventuality, you likely won't be driving a Jazz anymore, not many billionaires do

[ColinB]

It doesn't apply the brakes for you, it merely beeps to warn you that it thinks you are over the limit and it stops you accelerating so it will gradually reduce to the speed it detects unless you take action.

Not applying the brakes is the problem. If you're doing 60, and the car sees a sign on a parallel road reading 30, the system doesn't just stop you accelerating, it closes the throttle to actively slow you down: the deceleration can be quite sudden and unexpected, and the driver behind you doesn't see brake lights to warn him. Whilst we're all good drivers (everyone is, of course, above average!) there are people out there who aren't and a single clown tailgating you at the wrong time is all it takes.

Whilst I'm happy to accept the dashboard indication of the speed limit as a useful aid that's probably around 80% accurate, I regard the linking of that to the speed limiter as dangerous. Luckily you can choose not to use that facility.

[culzean]

It doesn't apply the brakes for you, it merely beeps to warn you that it thinks you are over the limit and it stops you accelerating so it will gradually reduce to the speed it detects unless you take action.

Not applying the brakes is the problem. If you're doing 60, and the car sees a sign on a parallel road reading 30, the system doesn't just stop you accelerating, it closes the throttle to actively slow you down: the deceleration can be quite sudden and unexpected, and the driver behind you doesn't see brake lights to warn him. Whilst we're all good drivers (everyone is, of course, above average!) there are people out there who aren't and a single clown tailgating you at the wrong time is all it takes.

Whilst I'm happy to accept the dashboard indication of the speed limit as a useful aid that's probably around 80% accurate, I regard the linking of that to the speed limiter as dangerous. Luckily you can choose not to use that facility.

My stand-alone Garmin satnav beeps at me when I am approaching a lower speed limit, and it beeps before the speed signs are visible a lot of the time,  it just uses GPS and is surprisingly accurate... you have to update your maps regularly though.

[Downsizer]

A GPS system will also spot the speed limits hidden behind summer foliage - there are quite a lot of those around the Suffolk by-roads.

[culzean]

A GPS system will also spot the speed limits hidden behind summer foliage - there are quite a lot of those around the Suffolk by-roads.

Quite a few road signs by use are covered with foliage and if they aren't they are covered with moss or other stuff,  pretty unreadable for us humans... 'council cuts' means they don't have a van going around keeping them clean any more ( they always cut the things people notice - except they don't cut the bushes hiding the signs LOL ) say no more.

[madasafish]

It doesn't apply the brakes for you, it merely beeps to warn you that it thinks you are over the limit and it stops you accelerating so it will gradually reduce to the speed it detects unless you take action.

Not applying the brakes is the problem. If you're doing 60, and the car sees a sign on a parallel road reading 30, the system doesn't just stop you accelerating, it closes the throttle to actively slow you down: the deceleration can be quite sudden and unexpected, and the driver behind you doesn't see brake lights to warn him. Whilst we're all good drivers (everyone is, of course, above average!) there are people out there who aren't and a single clown tailgating you at the wrong time is all it takes.

Whilst I'm happy to accept the dashboard indication of the speed limit as a useful aid that's probably around 80% accurate, I regard the linking of that to the speed limiter as dangerous. Luckily you can choose not to use that facility.

Thanks for that warning..

I will treat any driver of a new Jazz as a numpty then...


(No change from the driver of any new car especially OAPs who think they should be wrapped ion cotton wool and driven VERY slowly..to run them in as you would do to a 1950s car I suppose...   )

[John Ratsey]

A GPS system will also spot the speed limits hidden behind summer foliage - there are quite a lot of those around the Suffolk by-roads.

The sign recognition on the Mk 4 Jazz seems to do a better job of recognising degraded signs than the previous generation. The last speed sign number on the dashboard also blinks if the vehicle speed is more than about 1mph in excess of that number which is also a useful reminder.

The handbook says this about the intelligent speed limiter "Automatically sets the speed limit that the traffic sign recognition system detects. And the speed limit cannot be exceeded even if you are depressing the accelerator
pedal. If you fully depress the accelerator the speed limit can be exceeded." I haven't tried the system to find out how quickly the vehicle slows down but would note that taking foot off accelerator in when in D results in the vehicle slowing down more rapidly than on my previous CVT Hondas (if in B then deceleration is faster).

A bit of joined-up thinking could have linked the speed sign recognition to the sat-nav system if it contained a speed limit database. Although there's the risk of the vehicle getting confused when the two data sources disagreed, the database could be used to provide a speed limit in those situations where the car hasn't read a sign recently and just shows blank. This would be particularly useful in knowing if in a 30mph or 40mph (or even 50mph) speed zone. All have street lights but if there aren't repeater signs then the default has to be assumed to be the lowest speed (I wonder what the intelligent speed limiter does when the car hasn't recently read a speed sign?).

[equaliser]

The sign recognition on the Mk 4 Jazz seems to do a better job of recognising degraded signs than the previous generation. The last speed sign number on the dashboard also blinks if the vehicle speed is more than about 1mph in excess of that number which is also a useful reminder.

I'm glad to hear that John, the hardware and software algorithms should get better with each generation. They might get better faster now that manufacturers have a direct link to the control units via the built-in e-sim but thinking about it, they'll probably not bother to update them!

[ColinB]

I haven't tried the system to find out how quickly the vehicle slows down but would note that taking foot off accelerator in when in D results in the vehicle slowing down more rapidly than on my previous CVT Hondas (if in B then deceleration is faster).

I'd guess that the more rapid deceleration of the Mk4 is because the car starts regenerating when you lift off. If so, maybe the Mk4 is more helpful to the following driver than the Mk3 because a previous Q&A in this thread stated that the car does light up the brake lights when regenerating. So at least they will get a warning.