Posts by Matthew Poole
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Speaker: Sponsored post: Speed and Safety, in reply to BenWilson,
remember when the Harbour Bridge had no barrier down the center? There were fatal crashes every week, it seemed
You wouldn't be far wrong. In the early-mid 1980s, when all the Auckland motorways were undivided, the Fire Service's rescue tender at Manukau City fire station was the busiest fire appliance in the country (now it's the pump at Auckland City, which goes to thousands of false alarms in the CBD every year). The road toll was over double its current level. The government finally got serious about safety, put in median barriers, the number of serious collisions on the motorways dropped instantly and dramatically, and now fatalities on Auckland's motorways are never higher than very low double digits every year despite being, by far, the most heavily-travelled roads in the country and with a 100km/h posted limit (mostly) to boot.
Engineering is responsible for a huge amount of the decrease, both engineering of roads and engineering of vehicles.
As for your other post, if the through driver was driving defensively (a huge if in this country of untrained, low-quality drivers) he'd be starting to drop speed the moment he saw the car at the intersection. In that case he'd actually probably be able to stop, or at least swerve behind through that beautiful, wide intersection. But this is reality. Most drivers in NZ have more than 10 years of driving under their belt and they had very little testing and no professional training in order to get their licence. If they're over 50 and got their licence as a teenager they may as well have got their licence out of a Cornflakes packet for all the rigour of the assessment. The behaviour of not even starting to brake until it's obvious the other vehicle is pulling out is entirely consistent with reality, and the distances involved when that braking commences mean that the speeds will be upwards of 85km/h at point of impact. That is not a survivable side-impact speed for anyone who catches the other vehicle directly.
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Speaker: Sponsored post: Speed and Safety, in reply to Russell Brown,
I though the message was more that being in the right wasn’t a protection.
So have the guy doing under the posted limit! Because bringing in his over-the-limit speed means he's no longer "in the right". Now he's just a bad, speeding driver who's about to kill some innocent kid and his innocent dad.
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Speaker: Sponsored post: Speed and Safety, in reply to Greg Wood,
Let’s take a look at that using physics.
All else being equal, stopping distance at 100km/h = 49.2m, while stopping distance at 108km/h = 57.4m
8.2 metres is actually quite a long way into another person’s car.
Yes, but human reaction times are not instant. The through car is so close to the intersection when the other driver pulls out that it would take a very alert, very quick driver to have done much more than get their foot off the accelerator before impact.
We're not talking about pulling up short, we're talking about a near-full-speed side-impact collision at speeds that are not survivable until a heck of a lot of momentum has been lost. The ad shows a crash where a driver who was abiding the 100km/h speed limit would still have collided at pretty much their full speed with a driver who just pulled out in front.Watch the ad. Pause it at the moment where the car pulls out. The through driver has about a second to react, half a second of braking time if he's doing well. But it's not half a second, because by the time he's got his foot on the brake pedal the distance to impact (check out the aerial shot) is down to about nine metres, or less than 1/3 of a second at 100km/h (27.8m/s at 100km/h, 30m/s at 108km/h). Physics, also, says that maximum braking force is not immediately applied because it takes time to depress the pedal, for the brake fluid to compress and apply the brakes, the friction surfaces to make contact and begin slowing the car...
The speed is irrelevant. Not even Michael Schumacher could have braked fast enough to stop it being a fatal side impact (ignoring that he'd likely have spotted the crash before it happened and taken early evasive action). -
Speaker: Sponsored post: Speed and Safety, in reply to George Darroch,
We’ve scrubbed off about 5km/h over the last decade, and that has saved a lot of lives.
Over the last decade the vehicle fleet has got safer and many of the worst roads have been improved. The annual road toll at Pukerua Bay has dwindled to somewhere around zero instead of being around five every year, to name one example. The dividing of SH1 between Hamilton and Auckland has, similarly, reduced the incidence of fatal collisions along that road.
The insistence that it's the focus on speed which has reduced the road toll is given lie by the incredibly patchy results for year-on-year holiday period road tolls. Sometimes they're up, sometimes they're down, despite the police pushing the 4km/h tolerance. If it was all down to speed, we shouldn't be seeing such huge variation.
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Speaker: Sponsored post: Speed and Safety, in reply to Russell Brown,
by halting time so the protagonists can reflect on their respective follies and what they are about to reap.
A message that might be less-controversially got across by having the through driver do something that does not carry connotations of blatant fault and risk-taking, like looking down to change the radio station, or getting distracted by a billboard. That moment of inattention is the real killer, not the difference between the 100km/h limit and 108km/h.
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Speaker: Sponsored post: Speed and Safety, in reply to George Darroch,
For an increase of 8km/h, there is about a 15% increase in energy in the collision, IIRC.
Yes, but the difference between 100km/h and 108km/h is negligible. You're not suddenly going to die because of that extra 15%. It's not the difference between 40km/h and 50km/h to a pedestrian hit by a car, which is fairly literally the difference between life and death.
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Speaker: Sponsored post: Speed and Safety, in reply to George Darroch,
That message is not that the person driving faster is a bad and reckless person, or that the father is blameless and in the right. It’s simply that accidents are more likely at speed, and when they occur the consequences are worse.
In which case, put the speedo on 100km/h. Why is “excessive” speed even important to this message? It’s not. The crash would occur with or without those extra 8km/h; it would still be devastating to the car that’s collected from the side, with or without those extra 8km/h. A T-bone collision at that speed is almost invariably fatal at open road speeds, and those extra 8km/h do nothing except detract from the message. They’re not needed to deliver the message.
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Speaker: Sponsored post: Speed and Safety, in reply to Graeme Edgeler,
Not four times as bad? Or some other even higher number? I’d have thought driving/crashing at 100km/h was much more dangerous than driving/crashing at 50km/h.
In terms of released energy, yes, it’s four times as bad thanks to the “squared” in the theory of relativity.
In terms of actual outcomes, though, it’s really hard to quantify. People die in head-on collisions at 70km/h. People survive head-on collisions at 100km/h. You can’t put a number on it, or really even a hard likelihood of an outcome. There are statistical models, but every single crash is a specific occurrence that can only be fed into such a model in the most generalised sense. ETA: The exception is a car colliding with a large truck, at which point the impact speed absolutely indicates a live/die equation for a true head-on crash.This ad annoys me. It implies that the guy who’s travelling 8% above the speed limit is doing something wildly reckless, something so far outside the realms of reasonable behaviour that it increases the risk dramatically. It doesn’t. It’s not even terribly much more released energy in a crash at the shown speed, and at 100km/h when the guy at the give way sign pulls out the through driver would barely have time to realise what was happening before impact.
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Hard News: The sphere of influence, in reply to Johnny Canuck,
It remains to be seen whether Te Herald will go on one of its overwrought moral campaigns over this though.
Having delved into the sewer that is "Your Views" (we do it so you don't have to), I was pleasantly surprised at how most of the comments were heavily skewed against National. Normally it's a National Party love-fest-in-an-echo-chamber, but there was a lot of naked vitriol going on.
The worm appears to be turning, at least on the ground, so I'm just waiting for the polls to catch up. If they ever do, of course. -
Hard News: The sphere of influence, in reply to nzlemming,
Coff, Ross Robertson
meh. Labour, Robertson, MP. Close enough :D