'Speed Choice' Workshop

[martine]

Yup, understood. To be accurate it needs an assistant in the car. They should have a secondary mirror, and can then select a random marker post (when it's safe - obviously the driver should check too) and call "brake" or something so as to include the thinking time element.

Yes indeed coz the HC assumes 0.7 second thinking time which at 70mph is over 70 feet before you've even hit the brake pedal . I reckon the 0.7 could be a lot longer in practice...fiddling with the radio, talking to a passenger, thinking about what's for tea tonight...etc .

[ScoobyChris]

To be accurate it needs an assistant in the car.

Don't you even think about it!!!

Chris

[TripleS]

Did they acknowledge any positive benefits of speed?

No. What did you have in mind?

In my experience, balanced messages are easier to digest as the recipients hear part of what they believe in there already.

People think it's all about misery and desperation and death and all that shit which is not to be ignored, but what they forget is the pleasure of it. Otherwise we wouldn't do it. After all, we're not fucking stupid. At least, we're not that fucking stupid.

<Enthusiastic applause>

Best wishes all,
Dave.

[7db]

Yup, understood. To be accurate it needs an assistant in the car. They should have a secondary mirror, and can then select a random marker post (when it's safe - obviously the driver should check too) and call "brake" or something so as to include the thinking time element.

Yes indeed coz the HC assumes 0.7 second thinking time which at 70mph is over 70 feet before you've even hit the brake pedal . I reckon the 0.7 could be a lot longer in practice...fiddling with the radio, talking to a passenger, thinking about what's for tea tonight...etc .

I *think* Stressed Dave quotes 1.5 as a practical measure.

[MGF]

People think it's all about misery and desperation and death and all that shit which is not to be ignored, but what they forget is the pleasure of it. Otherwise we wouldn't do it. After all, we're not fucking stupid. At least, we're not that fucking stupid.

Mark comes accross as quite stupid to me.

Whether you drive for pleasure or to get from a to b. the principle of appropriate speed applies.

It seems from Martine's post that most people appeared to benefit from the presentation so perhaps praise is due.

Or would that be too much to ask?

[manilva15b]

Slightly off-topic but anyway...

Spanish Road Traffic law states:

minimum following distance is 50m out of town and 70m on autopistas (120kph limit) - no minimum in town
Guidelines also say two seconds in good weather and four in rain (doubled for HGVs)
Marker posts on major roads are 50m apart

You'd never believe the above from 'normal' observed behaviour

[MGF]

People think it's all about misery and desperation and death and all that shit which is not to be ignored, but what they forget is the pleasure of it. Otherwise we wouldn't do it. After all, we're not fucking stupid. At least, we're not that fucking stupid.

'Mark' comes accross as quite stupid to me. Having said that heroin use and speeding are hardly analogous.

Whether you drive for pleasure or to get from a to b. the principle of appropriate speed applies.

It seems from Martine's post that most people appeared to benefit from the presentation so perhaps praise is due.

Or would that be too much to ask?

[TripleS]

People think it's all about misery and desperation and death and all that shit which is not to be ignored, but what they forget is the pleasure of it. Otherwise we wouldn't do it. After all, we're not fucking stupid. At least, we're not that fucking stupid.

Mark comes across as quite stupid to me.

Whether you drive for pleasure or to get from a to b. the principle of appropriate speed applies.

It seems from Martine's post that most people appeared to benefit from the presentation so perhaps praise is due.

Or would that be too much to ask?

Mark seems to express himself in fairly robust fashion, but that doesn't make him stupid. Why do you say that, David? Is it the apparent disregard of diplomacy that concerns you?

We should always be thinking in terms of appropriate speed, but it's just that certain people will at times elect to use appropriate speeds somewhat in excess of the posted limits.

As for the speed awareness courses, by all means let's give them credit where it's due, but I just hope they don't simply bang on endlessly about the 'speed kills' message.

Best wishes all,
Dave.

[crr003]

The 2 second gap is about the distance between 2 lamp posts which is the same as the distance between the "keep apart 2 chevrons" which are marked on the motorway at certain places. the little marker posts, with the number on them and the direction of the nearest emergency phone, are ABOUT 4 seconds apart.

The chevrons are supposed to be 40m apart. (I found this googling HA chevrons somewhere once).
Ground speed @ 70 mph is about 105 fps or 31 m/s
So 2s worth of distance @ 70 is about 62m
But, if we take the standard thinking time of say .67s, this equates to 21m @70 (HC number)
So it seems the HA is allowing a safety factor of nearly twice the thinking distance as a recommended following distance. But it's not a 2 second gap of distance.

I'll try and measure the chevron gap.

[crr003]

Guidelines also say two seconds in good weather and four in rain (doubled for HGVs)

Scenario 1. Car B is following car A at 70 mph with a .67s gap (Highway Code thinking distance), or even a 2s gap to allow for reduced neurons.

Car A brakes "suddenly" and comes to a stop say the HC distance of 75m further down the road. Allowing for thinking distance, car B brakes and comes to a comfortable stop without hitting car A (assuming car A doesn't have Porsche ceramic brakes..).

Scenario 2. The same as scenario 1, except it's wet. Assume the same 2 second gap for thinking time. (Not 4 seconds). Car A brakes and stops in let's accept twice the dry stopping distance = 150m. Car B reacts within his thinking time of 2 seconds and brakes also at 150m, missing the rear of car A.

Why does the book say double your following distance in the wet, when your thinking time is the same and your braking distances are both doubled (i.e the same)?

What am I not understanding here?

[vonhosen]

Guidelines also say two seconds in good weather and four in rain (doubled for HGVs)

Scenario 1. Car B is following car A at 70 mph with a .67s gap (Highway Code thinking distance), or even a 2s gap to allow for reduced neurons.

Car A brakes "suddenly" and comes to a stop say the HC distance of 75m further down the road. Allowing for thinking distance, car B brakes and comes to a comfortable stop without hitting car A (assuming car A doesn't have Porsche ceramic brakes..).

Scenario 2. The same as scenario 1, except it's wet. Assume the same 2 second gap for thinking time. (Not 4 seconds). Car A brakes and stops in let's accept twice the dry stopping distance = 150m. Car B reacts within his thinking time of 2 seconds and brakes also at 150m, missing the rear of car A.

Why does the book say double your following distance in the wet, when your thinking time is the same and your braking distances are both doubled (i.e the same)?

What am I not understanding here?

You can see less because of the spray.

[martine]

Why does the book say double your following distance in the wet, when your thinking time is the same and your braking distances are both doubled (i.e the same)?

What am I not understanding here?

Isn't the point that the hazard might be stationery and not the car immediately ahead? How about something masked by the car ahead who swerves to miss say debris in the road, a previous accident, car entering from the hard shoulder at low speed, vehicle breaching the central reservation, brick from overhead bridge etc.

I expect there are loads of scenarios that won't be eminating from the car ahead and braking in a nice controlled HC stopping distance.

[ROG]

The 2 second gap is about the distance between 2 lamp posts which is the same as the distance between the "keep apart 2 chevrons" which are marked on the motorway at certain places. the little marker posts, with the number on them and the direction of the nearest emergency phone, are ABOUT 4 seconds apart.

The chevrons are supposed to be 40m apart. (I found this googling HA chevrons somewhere once).
Ground speed @ 70 mph is about 105 fps or 31 m/s
So 2s worth of distance @ 70 is about 62m
But, if we take the standard thinking time of say .67s, this equates to 21m @70 (HC number)
So it seems the HA is allowing a safety factor of nearly twice the thinking distance as a recommended following distance. But it's not a 2 second gap of distance.

I'll try and measure the chevron gap.

M1 southbound Watford Gap services to J17 the chevrons are painted almost in line with the lamp posts.
The 2 second gap is the MINIMUM that should be kept apart and just like speed limits, is not a target.
IMHO I think the HA knows that to put them apart too far will result in non compliance and at the distance they have put them will result in mainly vehicle damage and not serious person injury.

[crr003]

The 2 second gap is about the distance between 2 lamp posts which is the same as the distance between the "keep apart 2 chevrons" which are marked on the motorway at certain places. the little marker posts, with the number on them and the direction of the nearest emergency phone, are ABOUT 4 seconds apart.

I'll try and measure the chevron gap.

I measured the gap yesterday and I got 39.7m, so allowing for parallax error, I'll stick with 40.....
At least on the M6 in Cheshire.