Speeding article

[Jantar]

Here's trouble:

Research had found that on the open road, the number of road deaths fell by about 4 per cent for every 1km/h reduction in mean speed.

....

So if we lower the speed limit from 100 to 80 km/h then the number of road deaths will decrease by 80%? If they have that right then why were there almost double the number of road deaths when the speed limit was 80 km/h?

[Edbear]

Maybe so Ed. However, there's nothing wrong with knowing the how and why of things, it's healthy for the mind.

Interestingly enough, Oz has had a major rethink on the open road speed limit in their Northern Territory.

True of course. However there is little point in getting wound up about things and jumping on our high horses and attacking TPTB. We live in a society, much like our exended family with the same dynamics. There are those we like and love and naturally get along with and those that chalenge our forebearance and patience, and some we simply don't like at all.

As long as we remain in the society we have to accept the good with the bad if we can't effect change. So we compromise for the common good and eccept a couple of things we disagree with and appreciate the benefits. As with family, if you don't like living in it, you can lobby for change or leave and go somewhere you can have things more your way.

Bottom line is, tolerant and outgoing, generous people will always be happier than intolerant selfish people, who demand to have their own way.

That little old man/lady who is travelling too slow for you.. have a think about what their life is like and what it may have been. How do they feel about losing their independence and diminishing health? If they are NOT driving dangerously have a bit of patience as you will be them one day and sooner than you want.

Certainly enjoy your youth and vigour, but realise that short of living on your own island, you have to accept others in your life and your society. Each has their own strengths and weakenesess as do you, and you'll be much happier if you display patience and circumspection and choose your time and place for stretching the rules.

[bogan]

So if we lower the speed limit from 100 to 80 km/h then the number of road deaths will decrease by 80%? If they have that right then why were there almost double the number of road deaths when the speed limit was 80 km/h?

Just highlights the way the stats are being used instead of listened to. More fuel for the machine, full (only figuratively of course) speed ahead.

[Jantar]

Loving your logic.

So two vehicles with traction seatbelts, 20 fucken airbags, crumple zones etc hit poles. One is doing 100 kmh, and one is doing 110 kmh.

Which one will generate the greater energy from the crash? Which one will have the greater damage?

Both will be industrially munted, but which one is worse? By your logic, they will both be the same.

Go on, answer that.

If both vehicles are the same weight then the logic is correct and damage will be similar to both vehicles. In fact the one travelling at the faster speed will possibly result in slight less injury to its occupants than the one travelling at the slower speed.

There are two principles in play here: conservation of momentum; and conservation of energy. If the collision is completely inelastic then the 2 vehicles will effectively meld together with a resultant speed of 5 km/h in the direction of the faster vehicle (conservation of momentum). The energy released is identical in both vehicles as they have both experienced a change in velocity at impact of 105 km/h.

However it is extremely unlikely that in this scenario that the impact would be completely inelastic, and there is likely to be some rebound. A vector analyisis of the crash would be required to calculate the exact effects, but it is likely that the slower vehicle would rebound at closer to 180 degrees while the faster one would have a greater deviation. Thus more energy would be impacted in the slower vehicle rather than the faster one.

[slofox]

Hey! I know! Why don't we limit speed to 4miles per hour and get a man to walk in front with a red flag...oh...hang on...

[Akzle]

So two vehicles with traction seatbelts, 20 fucken airbags, crumple zones etc hit poles. One is doing 100 kmh, and one is doing 110 kmh.

Which one will generate the greater energy from the crash? Which one will have the greater damage?

Both will be industrially munted, but which one is worse? By your logic, they will both be the same.

Go on, answer that.

i would expect the one doing 110 to better, on account of it has more energy to transfer into les powerpole, resulting in less remaining in the car. something to do with exponential something or other.
even if i'm wrong, surely i have a right to drive into a powerpole at whatever speed i want?

also, it's almost irrelevant. two identical vehicles with identical safety features et al will do the same in a crash: crumple around the box.
done by crumpling front and rear, transferring energy around the cage and dispersing it, this is why we have A pillars in front and torque boxes in back. (talking uni-bodys here, not SUVs with rigid chassis') hit the pole at 160 for all i care, the energy will still be directed away from the occupants. (unfortunately.)( i think cagers should heave to wear neck belts, so they're actually going to wear the consequences of their tomfuckery)

...We live in a society, much like our exended family with the same dynamics. There are those we like and love and naturally get along with and those that chalenge our forebearance and patience, and some we simply don't like at all.

guess which group you're in.

[Zedder]

So, a 4% reduction in deaths for every 1 km/hr below the speed limit? So if I do 25 km/hr below the speed limit then I'm absolutely safe? Don't think so. Anyway, it's not the speed that kills you. It's the sudden stop - but I think that's been covered by the physics discussions.

I've taken a job here in Queensland and the urban speed limit is 60 km/hr. In NZ in a 50 km/hr area I usually do 60, it's just the natural speed for the car and me. Here in QLD I do 60 km/hr - not because it's the posted speed limit but because it's just the natural speed for the car and me. I suppose I'm more focussed on the road as I don't have to keep looking at the speedo to check if I'm in the fine payment range.

The having-to-focus-on-the-speedo-for-fear-of-fines syndrome was one of the main aggravations that came up in the Northern Territory speed limit issue.

I just got back from there recently and things are uneasy due to the "speed" drama. I don't have to be back 'til May so do some biking for me.

[Banditbandit]

So if we lower the speed limit from 100 to 80 km/h then the number of road deaths will decrease by 80%? If they have that right then why were there almost double the number of road deaths when the speed limit was 80 km/h?

No, sorry . it's the same as cummulative interest - only in reverse ..

so 100 to 99 = 1% drop or 1

99 to 98 = 1% drop or 0.99

etc etc ... I'm crap at actual arithmatic .. so one of the brighter ones can work it out ...

[Scuba_Steve]

So are we putting bets on whether they're rolling out their "oh so successful" 4km/h tolerance permanently this year?

I noticed yesterday a couple PIGs hiding themselves right at the start of the passing lane, made for a long line of traffic I had to push past 140 to pass

[Banditbandit]

It might be crash testing isn't done at 100kmhr impact (except by the good folks at mythbusters obviously), cos unless the driver a complete muppet, brakes will be applied? I dunno.

Yeah .. brakes will be applied - but not always and not always in enough time ... so there is normally a speed reduction ... but if there is not, then the question remains .. how good is the safety equipment at real open road speds? ???

[Jantar]

No, sorry . it's the same as cummulative interest - only in reverse ..

so 100 to 99 = 1% drop or 1

99 to 98 = 1% drop or 0.99

etc etc ... I'm crap at actual arithmatic .. so one of the brighter ones can work it out ...

They neither state, nor imply, that the effect is geometric rather than arithmetic. However if that is the case then reducing the average speed to 80 km/h would result in only 44.2% of the road deaths that occur at 100 km/h. Again that is the opposite of what we experienced here in NZ when the speed limit was reduced to 80 km/h.

Statistics show that there is a decrease in the road toll as speed limits increase.

[Zedder]

Here's an article from the UK about being able to do 86mph (yep mph) and not get a fine etc: http://www.dailymail.co.uk/news/arti...ape-fines.html

[Akzle]

how good is the safety equipment at real open road speds? ???

quite.
. .

[Akzle]

Here's an article from the UK about being able to do 86mph (yep mph) and not get a fine etc: http://www.dailymail.co.uk/news/arti...ape-fines.html

and why wouldn't you trust this guy?:

[p.dath]

I like the bit that says "speed" was a factor, and then they infer that "speeding" is the cause.

Of course any vehicle involved in an accident that is not stationary will have "speed" as a factor. This does not mean that the vehicle was exceeding the posted speed limit.