EmVeeSquared wrote:
Here's where the "safe speed" argument breaks down, for most people.
(1) Driving provides a wide range of speed cues beyond your instrumented speed on the speedometer to which we are very sensitive: engine noise, road noise, wind noise, visual cues, accelerator position, etc. Once an absolute speed has been determined from inspection of the speedometer, that speed can be maintained within an error band for sufficiently long periods by exclusive reference to speed cues.
To a certain extent - but size of wheels can also make subtle differences. Then road polish.. gradual gradients.. cambers: these all affect "feel and engine sound" - which some will not discern in today's cars. It appears why there is a move to "make engines throaty again" (per Autocar a few months ago
People also have different perceptions and one of the real "killers" happens to be "cruise control" whereby some folk think
1. Other persons must drive to the speed they have set the car to.
2. Some
think this device automatically applies the brakes
3. Some set it.. brake or press accelerator - thus knocking it off cruiser - but complacently think they have set the control and are at "legal" - and get pinged
OK - so they are perhaps "thick" to think the above - but they do
as they are lulled into some kind of complacent void
of full faith in their on-board toys. Oddly - we seem to find these people are the ones we tug and tell us they are in favour of speed cams as these are "more accurate than ourselves - and we should be using the time freed to go catchy some real criminals"
Only - errr.. we have the doo-dahs in the cars and usually go for theim as they must be dangerous since they never even saw us comiing
But it's still about COAST and still about being able to stop safey, smoothly and comfortably on your own side of the road well within the distance you can see to be clear and within the limit point. You usually find then that by adhering to COAST principles, you usually are at the safest speed for the traffic conditions and normally legal anyway
That is the real safespeed message - along with having more of us on the road too
Quote:
(2) The error band will vary from driver to driver, but in any case is unlikely to exceed 20%. The skills required to establish your personal error band is no more difficult than the skills assumed by adherents of so-called "safe speed" theory i.e. a "safe speed" adherent cannot argue that it is impractical without arguing also that his own theories are impractical. Anyone incapable of maintaining a set speed within 20% for short periods by reference to external cues lacks the necessary aptitude for controlling a heaving object moving at life threatening speed in a public space and should be prohibited from holding a license.
As has been pointed out to you 10% + 2 for an ephemeral second at cam point is the ping guideline setting
You can be 10% below - before and after - but, if for some reason, you increased slightly on a slight gradient at the cam point (where many are so stratgically placed
) - you can receive points on a licence. By the way - in the UK - we spell it with a C
20% on 30 mph is still 36 mph and 48 mph in a 40 mph zone
Hardly what you could call acceptable
and the sign of some complacency here - whereas at the moment - some areas are pinging for as little as 10% and the average driver will be fluctuating between 10% 1 or 2 0r 3 or 4 upwards and downwards on any one drive. It's why we tend to follow for a while to check they are safe enough here
Amazing how the sight of a cop car of knowldge that it might be lurking somewhere focuses the concentration
for a long period
Quote:
(3) To drive "safely" (in the sense meant by so called "safe speed" adherents i.e. in a way undistracted by the requirement not to exceed a given absolute speed), it is necessary therefore simply to drive to a lower limit which is the absolute limit less your own experience-derived error band. For example, a driver may choose to drive at 30mph in a 40mph zone, and 60mph in a 70mph zone. In this way, speed variations arising from the the driver's reference to speed cues can never result in him breaking the limit.
We have prosecuted fro driving below the speed limit on the grounds of inconsiderate driving in the past. I would hope that the driver who chooses to drive at 60 mph keeps to L1. We will pull up for ML moronic behaviour for words just as we do for blatting and tailgating.
Similarly -- - to drive at way below the speed limit could suggest "over-caution" and experience of over-caution has sometimes ended up with the person testing positive for "having one for the road"
We find driving within the flow of traffic and maintaining a decent distance usually prevents road rage, enhances courtesy and most importantly - helps drivers concentrate by applying this code of normal courtesy,, interacting and "socialising" with other road users. It also helps prevent the risk of collision with anything too.
Quote:
(4) Such a mitigation would only be unacceptable if the disbenefits of increased trip durations were greater than the aggregate disbenefits of road user deaths caused by increased vehicle speeds and the alleged distraction of attempting precision, instrumented speed control under conditions of externally imposed speed limits. In the worst (unachievable) case of a journey undertaken by an individual with a 20% error band entirely under the national speed limit exactly at a 20% average speed reduction, a 70 mile journey will take an additional 15 minutes. For representative journeys, error bands and average speeds, the same 70 mile journey will take an additional 5 minutes.
"Safe speed" arguments boil down to an argument that avoiding a theoretical delay of 5-15 minutes on a 70 mile journey is an important goal, for which disproportionate attention to vehicle instrumentation is necessary and dangerous.
We don´t agree.
The argument here is one which forces folk to think about driving standards.. focus on good practice and COAST values. It is not about a complacent attitude by thinking zero accident will occur because the driver happens to obey a speed lollipop. Safety is about much more than the odd speed camera placed behind a bus shelter on a slight downward gradient. It's about forcing people to think... take a pride in their driving .. critically evaluating and constantly learning and developing skills. Learning how to use the in-car toys properly and also recognising the limitations of these "safety devices"
The T in COAST stands for Time.. as in "based on your observation and anticipation of hazards - you PLAN by creating Space and Time to pro-act and react
. The Time also means allowing sufficient time for the journey.
By the way - you travel 33 yard per second at 60 mph and 36 yards per second at 70 mph It does not sound much - but it can mount up for professional drivers covering a long journey all the same with the same bleg stretch allowance every 2 hours ..
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