What an excellent post, Ed. Bizarre, isn't it, that the proffered interpretation of data that says older drivers with ABS have more accidents is to suggest that they don't know how to utilise the technology... which surely involves no more than applying the brake?! As so often, researchers are overwhelmed by the variables. (Never mind, it's one more publication for the CV.)

Even when I had a lot of disregard for speed limits, because I was driving a fully expensed company car on their insurance, and subsequently a lot more subdued - I've never had ABS activate in anger although I've tested the ABS in every car I've owned that had it - as an older male driver I'm not sure how the inclusion of drivers like me in a study of ABS effectiveness would prove anything useful.

I don't believe that older drivers do have braking skills which match ABS - but I do believe they generally drive within limits far enough away from the limit of adhesion that ABS is rarely needed.

Even when I had a lot of disregard for speed limits, because I was driving a fully expensed company car on their insurance, and subsequently a lot more subdued - I've never had ABS activate in anger although I've tested the ABS in every car I've owned that had it - as an older male driver I'm not sure how the inclusion of drivers like me in a study of ABS effectiveness would prove anything useful.

I don't believe that older drivers do have braking skills which match ABS - but I do believe they generally drive within limits far enough away from the limit of adhesion that ABS is rarely needed.

That would expain a lack of a protective effect of ABS in older male drivers. It does not seem to explain why ABS would actually apparently raise the accident rate in older male drivers (and women) slightly.

I looked at the first paper a bit more. They discuss two questions, one on the operation of ABS brakes, the other on the effect of ABS in maintaining steering. Younger male drivers answering the first question correctly had fewer accidents, whether they drove ABS cars or not, suggesting it may be a general driver awareness benefit.

The protective effect of steering knowledge was specific to ABS drivers, suggesting it might indicate the ability to actively avoid or mitigate an accident

While the protective effect of ABS knowledge for older male drivers and women reduced the accident rate,even the most knowledgable ABS older male drivers had a higher accident rate than non ABS drivers

The authors suggest

"Various hypotheses can be advanced. For example, it could be that younger men tend to be physically better able to exert the necessary force on the brake pedal, or that they respond better to the feedback provided by ABS, or that they are more likely to perceive an emergency in sufficient time for the system to act effectively."

But again, those explanations dont appear to explain a negative effect of ABS. For that you would have to resort to either older drivers being superior to ABS, or ABS activation startling older drivers into poor responses

I also looked at sample of citations for this paper, listed here,

www.researchgate.net/publication/11427706_The_effe...n

for papers giving more convincing support for ABS accident reduction, but didnt find any.

A cynic might suggest that they were afraid to look.

Edited by edlithgow on 24/05/2025 at 14:30

John F. Why aren't you fixing it yourself now you've carried out the diagnosis?

1. I've no code reader and virtually zero knowledge of modern car electronics, so I haven't actually made a precise diagnosis..

2. Might not be a simple replacement of sensor. It might be something to do with their control unit, whatever and wherever that is. There's an interesting u-tube of someone replacing some of four diodes which had failed in a small 'black box' control unit which involved sawing it apart and some tricky soldering.

3. My trusty indy of decades has retired and I'm in the process of developing a relationship with a new one. I'll see what he makes of it.

4. I'm busy gardening and reading.

5. Aftermarket parts, by all accounts, are rather frequently junk.

On this Peugeot, they’ve got magnetic reluctor rings attached to the wheel bearing . The abs sensor picks up rotational speed from these

He did mention it might be a faulty bearing, but I assumed that's if the front ones had been faulty?

Normal procedure is to cut the old ones off, clean the mating surface then tap or press the new one on, did you get to see your old disc's and pads John?

No, but it clearly now has nice shiny new ones. At least we got 32K miles out of the old ones.

John, if your car has been designed with brake discs containing speed sensors, thereby being liable to silly failures such as you describe, I am surprised that you haven't commented on the foolishness. Surely your new indy can't have sold you new discs and pads having fixed some other trifling sensor fault ? :-)

Think he may have done Andrew :)

I suppose it's possible but it seems a decent long established family business.