GPS doesn’t always give an accurate speed reading – ever had a look at your GPS track if using a fitness app like MapMyRun? It can be out by a few metres here and there, which must have an impact on your speed calculations, so GPS is not as infallible as many people believe
It's certainly not very accurate for an instantaneous reading. But for a reading over time, since it is based on absolute location, and is smoothed out by the accelerometer (which gets very confused by being waved around as you run), it's far more accurate than something counting the number of times your wheels turn. In a vehicle going 27 meters per second, with a polling interval of a few seconds at a time, and the "meter here meter there" averaging out to the exact location, you've got an excellent doublecheck on your speedometer (and also, for that matter, the odometer). You'll definitely be able to detect it being out by 10%. The app I'm talking about gives you continuous feedback on how many satellites it is using, so you know when it's getting a really good reading.
Part of being a good driver is being aware of distance and speed – if you are having to use an app to keep under the speed limit, then you are probably not sufficiently aware of your speed, and you should be paying more attention to the task at hand.
My point was that our speed can rove up or down 5km/h at 100km/h within perfectly normal driving (in Auckland, which has hills). The only way NOT to do that is to micromanage your speed, braking and accelerating at every little deviation, or sit well below the limit.
In terms of the actual need to use the app, I only every use it on long motorway trips. It's very easily to lose concentration on the speedo, since you're focusing on the road. I can't see it being a negative to have an app that helps. It would be nice to say that I never ever, ever forget to glance at my speedo every 5 seconds, but that's not realistic.
Droid, soz. Could be on iPhone, it's called "Ulysse Speedometer". There's lots of these types of apps.
Speedometers are normally calibrated/designed to overread – this is apparently required in AU and the EU.
It's one of the cool things about GPS. You can test your speedo quite easily. I have an app that hassles me if I'm going over 100km/h on my phone. It's interesting to try to drive to that - it gets really, really irritating if you set it to actually go off on 100km/h, and then want to drive at 100km/h. It goes off half the time. The only way to avoid being nagged by it is to go 95 on average. Or set it to 105. Quite instructive about what does actually happen with your speed on average - we don't micromanage it, on the whole, nor should we.
It’s the millions of New Zealanders who gained their licenses in previous decades and have never since been tested on their abilities that I’m more concerned about.
I think refresher testing is not a bad idea, but accident statistics suggest that there's not going to be much bang for your buck on the older demographics, who have by far the lowest accident rates already. It's not really the knowing of the law that's the issue in bad driving. It's the obeying it, including the hard-to-enforce ones like following distances, and taking poor conditions into account. And also the general improvement in overall road sense that steadily builds from endless repetition, close shaves, minor accidents.
Is there another dangerous machine that you would you put people in charge of without ever reviewing their ability to use it?
Unfortunately, yes. There are currently no laws requiring licensing of any kind to drive extremely powerful small boats, nor any manditory seaworthiness testing for the boats, and there's very little by way of DIC controls. And people die frequently as a result. Which is not an argument not to improve road safety, but is a strong one for improvement of sea safety regulations.
If the tests are relevant to driving, is it possible that people who suck at that sober shouldn’t be driving even when sober?
That's always been the rub. You couldn't make the test too hard, if it was the decider, people would be failing it left right and center. But it's just a filter, aa way of narrowing down to who to do a chemical test on. For that purpose, it sounds efficacious, although still a hell of a lot slower than getting me to say my name into an alcohol sensor. The manpower requirement would be huge.
Just for fun:
With impairment tests, I would think that it’s hard to get a fair baseline – some people are simply not very good at standing on one leg, for instance. Most old people struggle with it. But presumably the point is to use the test as a filter to then administer actual chemical tests.
I prefer impairment tests that are relevant to driving, though. I don’t ever stand on one leg when driving. Reaction time, and maybe distance/speed perception would be better ones. Can they catch a ball? But again, there’s a lot of people who suck at that sober.
It's pretty clear it impairs you. The question is, as you say, how much?
it might be that the type of person who crashes is the type of person who has cannabis in their system. I’m very careful not to mix correlation with causation.
It’s a complex question indeed. I don’t know how they could be separated. Good statistical analysis of crashes is probably the best we’ll ever get, although the jump from impairment to higher chances of crashing is highly plausible. The only counterbalancing force is that people who are cautious can take their impairment into account. So the statistical question isn’t “can they drive safely?”, it’s “do they?”. In the case of alcohol, it’s pretty clear the answer is no.
If anyone is missing the point it’s people who think defending talkback jocks’ right to give shit to young women about whether they deserve to be raped is a good metaphorical hill to die on.
Indeed. It's been a wake up call for me about how some people prioritize their values, and just what is actually important to me.
That's a very good article Anne R. I shouldn't have saved it up until this morning, though.
I supported what Gio and others were doing because it was sending a great useful noisy message I agreed with. Yeah, maybe (and only maybe) it wasn’t technical best principled practice in a world where our one goal is freedom of speech.
Well said. Annamarama. There's something very odd about "that's a bit below the belt", when it comes to fighting rape culture.