Safe Speed Forums

Have you considered gravity and hills? Going up-hill and maintaining 40mph requires the use of the throttle and a loaded engine, however having crested the hill most cars will then coast down the opposite side on zero throttle with a much lower level of noise despite the fact that they are going faster (and may even be accelerating). Many vehicles may even select different gears. The idea that sound can be used as the primary tool for maintaining speed (as was suggested by Blundstum) is very flawed.

having crested the hill most cars will then coast down the opposite side on zero throttle with a much lower level of noise despite the fact that they are going faster (and may even be accelerating).

For any that don't know, 'timbre' usually refers to 'harmonic content' and explains why (for example) a volin and a trumpet playing the same steady note sound completely different.

Sorry. That referred to the original post in this thread by freddieflintoff, in which he refers to being NiP'd for doing 48 in a 40.

My point was not that being able to judge speeds to a tolerance of 8mph either way is sufficient, but that you should be able to tell that your speed's crept up, without looking at the speedo, long before you reach 8mph over the limit.

Using different cars hinders the process of speed perception by the driver too I imagine.

But the question I always raise when any discussion around risk and speedo checking is that to my knowledge it has never been quantified.

This is irresponsible given how easy it would be to clarify:

-how long a speedo check takes
-whether speed enforcement (perceived/real) causes significantly more speedo checking
-how speedo checks impact on hazard perception, reaction times etc

Its a potential side effect which has never been considered. We have, (for research purposes) methodology precedents, the technology (simulators/ visual gaze tracking and the understanding of how visual attention works at a cognitive level. Opinion isn't enough. Where's the science?

Ah but if it is a 15%+ down slope with a considerately placed Gatso halfway down, I think that you will still find that you need to watch your speedo - a lot. My car is not exactly quiet, and the exhaust can always be heard, as can the tires, and while I don't have perfect pitch I am a musician with 30 years of guitar experience, and I still find myself watching the speedo for up to 50% of the time on the approach to these Gatsos (yes really that much) just to be certain that gravity isn't winning.

I can think of 3 Gatsos placed in this sort of position, two of which are right besides a deliberate narrowing of the road so most of the rest of the concentration is on vehicle placement, and virtually nothing is available for looking for that suicidal child running out. My wife says that she thinks that it isn't a problem, yet last time she drove my car through one of these Gatsos she curbed the wheel taking away some serious chunks from the alloy wheels...

Edited to add: Two of these are also placed just within a reduction in speed limit, so there is virtually no time to get settled on a reference "note".

But a decent driver is probably checking their mirror every five seconds (if driving at normalish speeds in normal conditions)... If we assume a mirror check takes a second and a speedo check takes a second, that means we should only be looking ahead thirty six seconds a minute

If you don't know what speed you are going at, and are incapable of checking this every few seconds, then you shouldn't be driving.

Ah but if it is a 15%+ down slope with a considerately placed Gatso halfway down, I think that you will still find that you need to watch your speedo - a lot.

Doubtless you should also be able to pick your nose every few seconds.
If you can't then should you be driving?

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Well, you assume wrong. It takes me about a third of a second to check my speedo. The problem here is one of bad eyesight and inability to read properly. The drivers who claim they can't watch their speedo AND the road are clearly saying they are incompetent and shouldn't be driving.

Perhaps you have problems adjusting your focus from near objects to far objects?

I check my speedo every five seconds or so, as a habit.

It's automatic. If somebody pulled in front of me while I was doing this, I would still see them - haven't you got peripheral vision?

Perhaps you could get your speedo projected onto the windscreen, if you find it so difficult to check it.

If you don't know what speed you are going at, and are incapable of checking this every few seconds, then you shouldn't be driving.

If you can't check your mirrors every five seconds, again, you shouldn't be driving.

Anybody care to argue?

Not a good argument. Do you need to pick your nose to drive safely?

It takes me about a third of a second to check my speedo.

I check my speedo every five seconds or so, as a habit. It's automatic. If somebody pulled in front of me while I was doing this, I would still see them - haven't you got peripheral vision?

If you can't check your mirrors every five seconds, again, you shouldn't be driving.

Anybody care to argue?

I'm 40, and have perfect vision. Now I think I can see where the problem lies...
You're exactly right about the word 'glance' - that's all it takes. That's all it takes when I check my mirror. A glance. Nothing more.
I presume nobody here stares straight ahead constantly while they are driving? So they look over at the left hand side of the road, to the pavement, or a road joining from the left, or the right, etc. etc.? I spend exactly the same amount of time glancing at my speedo, and my mirrors. I look ahead, glance at the speedo, look ahead, glance to the left up ahead, etc.etc.



Well, thanks for clearing all of this up for me. You (and people like you) should have a different form of device for telling you your speed - an audible warning that says '30', etc. or maybe a set of different types of noises that rise in frequency as your speed increases, say one set for 20 to 30, one set for 30 to 40 (so you'd know when you'd gone over 30, as you'd hear a trumpet instead of a piano, for example).
If it takes you a full second to focus as you described, I worry about your inability to drive. I don't even take any noticeable time whatsoever to refocus, and how good a focus do you need to see if the needle is past 30 anyway? Is it THAT blurry when you first look at the speedo?


No, your bad eyesight renders you a danger.
I hope I never drive on the same roads as you!





And therefore you think it's okay to SPEED when your eyesight is going down the pan? Strange logic indeed!





You can only speak as somebody who has bad eyesight. I can see perfectly, and my peripheral vision is excellent. If the car in front slowed down, etc. while I was glancing at the speedo, I would notice it. I notice it all the time. I am aware at all times of what is going on all around my car. Who's in front of me, how close they are, who's behind me, how close they are, how fast they are travelling, what's happening on the left and right, etc.etc.
Unfortunately, a lot of people's minds are too busy thinking about something else, and they can't form this simple mental model very well.
I'd love to show you how 'dangerous' my driving is - it's not dangerous at all. Every time I take a person for a drive in my car, who's never been driven by me, they always say how courteous I was. I'd resit my test tomorrow, and every year for the rest of my life, quite happily. It's funny how all the speeders on here baulk at such a proposition...






You're only speaking for yourself. Perhaps your speedo is located somewhere around your foot pedals? Mine's right at the top of the dashboard, so it's impossible NOT to see the car in front of you while you GLANCE at the speedo.






No, it's because most people have good enough eyesight to check it constantly. It's part of your driving test. You would fail if you retook your driving test today, so why are you still driving?






But who is going to decide WHO can speed, since so many drivers are bloody useless even when they remain WITHIN the current speed limits? How is your "I'm more important than anybody else, plus I'm really angry and aggressive and I deserve to speed" idea going to actually WORK in the real world?







So you have eyes in the back of your head? How does peripheral vision tell you that a speeder (quelle surprise) has driven up the back of you, at 40mph, in a 30mph zone? That's why you need to check every five seconds (actually, I think I check far more often than that.)





You meant to say "unlike speedo checks FOR ME WHO HAS BAD EYESIGHT".
Don't try to make out that we're all incapable of focussing properly - I've been doing it fine for 20 years.

mosis
mosis wrote:
I check my speedo every five seconds or so, as a habit.