Archive for February, 2010

Level Crossings

February 23, 2010

As a sort of postfix to my last entry, I’d like to add some thoughts on level crossings.  Occasionally, particularly after an accident has occurred, people wonder how anybody could miss the railway crossing lights.  I strongly suspect that this is the same sort of thing; we don’t get enough practice at stopping at railway crossings, because trains are so infrequent that we hardly ever need to.

As it happens I can present a personal anecdote on this subject: a year or so back I was approaching a level crossing, on my way home from work.  Now, I’ve needed to stop at this crossing before, but always behind another car.  This was the first time I’ve ever been driving the car in front approaching a level crossing with an oncoming train.

I swear it took me at least five seconds to realise the significance of the warning sign.  I reckon I came within a hair’s breadth of not realising it at all: if I’d been a little more distracted, or perhaps just a little more tired, I think I’d have gone straight through the crossing, and perhaps been killed.  Scared me half to death.

My answer to the problem: put in traffic lights.  You know, the regular red/orange/green sort that most of us experience every day and are used to stopping for.  I’m betting this would significantly reduce the accident rate at level crossings.

What do you think?  Worth a try?

Harsh Penalties Won’t Make Drivers Superhuman

February 23, 2010

Jennifer Speakman was sentenced last week for an accident in which her car hit a pack of cyclists, injuring several, one severely.  I was quite relieved at how reasonable the sentence was, considering the consequences to the victims.

An article on Saturday quotes one of the victims of the accident, and another victim was quoted today calling for harsher penalties.  I suppose this is legitimate news, but it seems coldhearted to preserve a permanent record of words spoken in anger, by men trying to come to grips with a life-shattering personal disaster – words they might reconsider later, but will never be able to take back.

I certainly don’t want to argue that the victims shouldn’t be angry, or to trivialise their suffering.  In fact, if it were just a question of the victims’ words, I wouldn’t say anything at all.  However, I’ve seen very similar opinions stated elsewhere, and suspect that it isn’t uncommon, particularly amongst fans of cycling.

Harsher penalties won’t make drivers superhuman.  I suppose cyclists are naturally inclined to blame the individual drivers involved in particular accidents because it helps them ignore the risks they choose to face; that’s a very human sort of reaction.  Also, we’re always keen on a quick fix, and talking about “educating drivers to share the road” sounds like just the ticket.  (Drivers and pedestrians make the same sort of assumptions; I don’t mean to single out cyclists in particular here.)

The stark, unpleasant truth is that this was an accident that could have happened to anybody.  Any one of us could have been behind the wheel on Tamaki Drive that day.

Ms. Speakman made two mistakes.  First and foremost she failed to see the cyclists.  Now, this sounds stupid.  We tend to believe that we see everything in our field of view, and that we couldn’t possibly miss a group of cyclists in orange vests.  Unfortunately, this is an illusion: humans really aren’t all that good at spotting things they aren’t expecting.

The next time you approach a T-intersection and are turning right (if you’re in a right-hand-drive country, make that a left turn!) or better still when you leave the intersection, think about where you looked.  You looked left at the traffic you were going to be merging with.  You looked right at the traffic that was coming towards you.  Odds are you didn’t look ahead into the intersection; there’s never anything there.  Except this time there was.

This is also the reason that airport screening is much less effective than you’d think.  The thing that really seems crazy if you’ve never learnt about how the brain works is that you can’t just choose to pay attention all the time.  Your brain won’t let you.

The other mistake Ms. Speakman made was to roll through a stop sign.  It isn’t immediately clear to me whether this would have made any difference, although I suppose stopping would have lengthened the amount of time her visual cortex had to process the shapes of the cyclists and raise an alert.  However, even if we assume that it would have prevented the accident, the same problem occurs – stop signs just aren’t very common these days, so we don’t get a lot of practice at stopping at them.  It doesn’t help that stopping almost never prevents an accident.

I take the bus to work most days, but sometimes I drive.  If I’m driving, I usually go through a stop sign on the way to work.  At a rough guess I remember to actually stop about half the time.  I’m not deliberately flouting the law, and each time I notice that I’ve done it I swear at myself a bit, but I haven’t managed to improve much.  Perhaps you do much better, but if so, I’m guessing you’re either a relatively new driver (and hence still driving consciously rather than as a routine task) or you happen to regularly go through an intersection where you really do need to stop.

Harsher penalties might make cyclists feel better.  But it won’t make them any safer, and it certainly won’t be any fairer.  If cars keep sharing the same roads with bicycles, and continue to be driven by humans, sooner or later this sort of accident is going to happen again no matter what else we do and no matter how carefully we drive.  I think we need to face up to that, and, as a nation, make the hard decision as to whether bicycles should be allowed on the road or not.  If we decide they should, that’s fine – but we need to be willing to accept the unpleasant, unavoidable consequences.

DISM corrupts images mounted to paths with short filenames

February 22, 2010

If you’ve been having trouble using DISM to update off-line Windows 7 images, make sure you aren’t mounting the image to a path which contains a short filename component.  In particular, note that the TEMP environment variable will contain a short filename component in Windows 2003 or earlier, and may contain a short filename component in later versions, depending on your username.

For example, if I were to create a folder on C drive named harryjohnston, this command would corrupt the mounted image:

dism /mount-wim /wimfile:c:\win7\install.wim /index:1 /mountdir:c:\harryj~1\mount

This wouldn’t:

dism /mount-wim /wimfile:c:\win7\install.wim /index:1 /mountdir:c:\harryjohnston\mount

If an image has been corrupted in this way, and is then used to install Windows 7 on a machine, the junction points on the target machine will retain the path of the mountpoint.  For example, the “Documents and Settings” junction point would point to c:\harryj~1\mount\Users instead of to c:\Users as it should.

Thanks to Joseph Conway from Microsoft, this issue has been filed as a bug and will hopefully be fixed in a future release of the WAIK (Windows Automated Installation Kit).  In the meantime, the workaround is obvious: use a different mountpoint. :-)

Hope this helps.


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