Interesting, how the brain works

[Pat ex]

First aid kits are also required in vehicles in many countries.

It's not my logic - its what they teach you in first on scene training.

Not just in the UK it seems

Blocking Techniques for Roadway Incidents

Jack Sullivan illustrates blocking and parking tactics for roadway incidents to protect responders and increase scene safety.

www.firehouse.com

That's mainly for emergency vehicles parked or 'blocking' in the normal lanes, to make it obvious that they are stationary. One would assume they'd have the blue lights flashing also.
It is understandable that vehicles make some sort of indication that they are stationary, when stopped in the normal lanes. The usual thing to do is use the hazard lights.
It makes no reference to the number one cause of rear end shunts on the hard shoulder.
But obviously the number one cause of rear end shunts on the hard shoulder is because one vehicle is stopped, and another is driving on the hard shoulder, when they shouldn't be. So the number one cause of rear end shunts on the hard shoulder must be because other drivers are not paying sufficient attention to their driving.

It's difficult to imagine a circumstance where a vehicle stopped on the hard shoulder is involved in anything but a rear end shunt.

 

[Harry Bloomfield]

Ice etc has nothing to do with it.

No, but it is easier to prove to yourself that the ABS is working on snow or ice, than a normal dry road surface. Even then, I have had incidents on icy roads where ABS and including the brakes have been almost completely useless. Back in the 70's returning home with a colour TV in the back of the car, I came to the downhill to drop down into the village I live and hit a sheet of ice. No grip at all, wheels locked and it just slid slowly down to almost the bottom, I couldn't even get the wheels to turn with no brakes on - followed by another car. Luckily there was no damage to either.

One cold afternoon and in a rush to get somewhere, taking the most direct route along back roads, I crested a peak to be met with an amazing sight just the other side - dozens of vehicle of all types, stopped, many of them on their sides, some had crashed through hedges, including a police car and van. I just managed to stop sideways on across the road without hitting anything. I tried to get out put it was impossible to even walk on the surface, so I just sat there, phoned it and explained I was stuck on ice - daren't move.

I sat there for a couple of hours and the ice cleared and I was then able to carry on. Guess it must have been a microclimate.

 

[ajohn]

Even then, I have had incidents on icy roads where ABS and including the brakes have been almost completely useless.

The ABS can only make use of the mu that happens to be there. Wet ice is fairly common in the UK = near zero mu. Drive in winter in Sweden and it's dry - entirely different and add studded tyres even better. That's what they do and also fit sump heaters, in the north anyway.

I've mostly worked on HGV and their trailers ABS but car needs are loosely similar. It needs to search out the mu level and also realise that it may change. Ideally it would set critical slip on all surfaces - tyre rotating a little slower than the road speed sets. This is not good for steering. Locked up wheels even less - a lot less actually. There was a lane change fad on car ABS for a while and some pretty awful systems were around. Worst I ever drove was a Xantia. The dam thing bump fired on me once so rear end shunted some one. I think all have wised up now but it's something I always check when I buy a car. On higher mu there should be decent periods of time without it cycling the brakes off for the wheels to recover. Sadly as mu may change this can't be perfect.

An F1 driver can do better. I looked at a test track after one tested a road car. Straight faint skid marks that faded out near the end - probably to improve steering response. The police have been confused in the past by ABS having the same effect, thinking the driver wasn't trying hard enough so are told to look for them. A particular German brand was a lot better in this respect but was only fitted to expensive cars. The crap started cropping up when they started getting fitted to most cars.

 

[Harry Bloomfield]

An F1 driver can do better. I looked at a test track after one tested a road car. Straight faint skid marks that faded out near the end - probably to improve steering response. The police have been confused in the past by ABS having the same effect, thinking the driver wasn't trying hard enough so are told to look for them. A particular German brand was a lot better in this respect but was only fitted to expensive cars. The crap started cropping up when they started getting fitted to most cars.

Any well experienced driver can usually do better than the ABS, using cadence braking. Trouble is we are now stuck with the lowest common denominator which is ABS - which has to be functional for the MOT.

 

[foxhole]

Any well experienced driver can usually do better than the ABS, using cadence braking. Trouble is we are now stuck with the lowest common denominator which is ABS - which has to be functional for the MOT.

Recent tests show even highly professional drivers were out performed by abs and abs always gave consistent results where pro drivers varied .

 

[motorbiking]

But a lot of cars have brake assist and that will out brake most people .

I never really got on with bikes with abs until I changed my emergency braking style. It was hard to match then and you realised just how hard you could squeeze the front before it would start to slip

 

[ajohn]

Recent tests show even highly professional drivers were out performed by abs and abs always gave consistent results where pro drivers varied .

That about sums it up.F1 drivers and their cars live in a different world. It's one of the reasons some F1 drivers do better than others but in their case the car is very significant as well.

HGV and their trailer braking moved on a while ago now. The brake pressure is measured on the fly which means the first skid pressure is known. Cars may have moved on to do the same but traditionally rear wheels have reduced braking to aid stability. I've worked on every 8 and 10msec wheel speed updates. Match that with your foot. Measured to 1 part in 2^16 and not all that far off in terms of actual accuracy.

In real terms a lot of heavy braking will be on a relatively consistent mu but variations have to be expected and dealt with going higher or lower. That means the ABS must cycle brake pressure in some fashion to find out if things have changed. I wish people luck with their foot.

Steering is tricky. Any degree of skid messes it up. Maybe at some point they will throw in purposeful steering angle changes into the mix as lane changes may be possible.That aspect needs considering in any case. Some degree of stable steering being left is probably desirable for the same reason load apportioning has been used front to rear on cars for rather a long time. Stability. Similar applies to |HGV trailers - preventing them from overtaking the tractor side ways on. This entire area needs compromise. Match it all with your foot. Most wont.

 

[transam]

Doc on the radio last night about some blind fella he is 19 and Afai recall is the first blind person enrolled at some prestigious music school ??

Any way the point is that he uses echo location to find his self around
His brain is trained to understand the different sound of clicks bouncing off objects

Walls in rooms ect ect objects in the street ect ect

Was on the radio last night

 

[Harry Bloomfield]

But a lot of cars have brake assist and that will out brake most people .

I never really got on with bikes with abs until I changed my emergency braking style. It was hard to match then and you realised just how hard you could squeeze the front before it would start to slip

I never had ABS on bikes.

 

[Mottie]

An F1 driver can do better.

Is that why you see frequent lock-ups and flat spotted tyres during a race?

In any case, ABS is not allowed in F1 and hasn’t been for some time.

 

[Harry Bloomfield]

Steering is tricky. Any degree of skid messes it up. Maybe at some point they will throw in purposeful steering angle changes into the mix as lane changes may be possible in any case that aspect needs considering. Some degree of stable steering being left is probably desirable for the same reason load apportioning has been used front to rear on cars for rather a long time. Stability. Similar applies to |HGV trailers - preventing them from overtaking the tractor side ways on. This entire area needs compromise. Match it all with your foot. Most wont.

The first ABS ads I saw, were for the Granada, where a tractor pulled out of a field entrance and the Granada banged the brakes down hard and steered round it. I got one soon after that.

 

[Mottie]

The first ABS ads I saw, were for the Granada, where a tractor pulled out of a field entrance and the Granada banged the brakes down hard and steered round it. I got one soon after that.

A mate of mine that worked in a body shop said they had quite a few Granada's in with rear end damage because the cars following them couldn’t stop as quick as them in an emergency braking situation.

 

[JOHNBOY42]

also as you get older after 40 the brain shrinks and loses cells at the rate of 5% per decade............... some dee head on here matured quicker

 

[Harry Bloomfield]

A mate of mine that worked in a body shop said they had quite a few Granada's in with rear end damage because the cars following them couldn’t stop as quick as them in an emergency braking situation.

I remember the stickers on the rear of some cars 'Warning - Disc brakes'

 

[ajohn]

The first ABS ads I saw, were for the Granada, where a tractor pulled out of a field entrance and the Granada banged the brakes down hard and steered round it

I did mantion the lane change period. A popular idea for a while.