Speed limiters to be fitted on all new cars by 2022

omens said:
Whilst a speed limiter might reduce the first figure, it will do nothing for the second. A driver could be driving at the speed limit and it could be too fast for the situation eg heavy fog, poor visibility, poor road conditions etc.

A few years back, I watched a documentary about speeding and they fitted a speed limiter to a car and filmed what drivers did. Turns out they paid less attention to the road because they didn’t to focus as much. Whilst some driver aids actually help with the job of driving, there is a danger some might enable complacency. Bearing in mind that the majority of accidents is down to driver error not (involving inappropriate or excess speed), we should focus on this. If people were very serious about reducing road fatalities, they would focus on the largest factor - the driver. Either mandatory retesting every 5 years, or ban all drivers in the first place.
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Apart from periodic retest, extra training would also be a good idea. I believe the Pass Plus is still run with some councils still providing funding. Although it wasn't run last year, Ford have run a Driving skills programme for under 24 yr olds. It is usually just in London and Manchester and has a limited number of places, but they simulate driving under the influence as well as driving while on a mobile as well as the normal stuff.
This additional training should really be made compulsory.
Personally I had to do a high performance (speed) driving course, just so I can test the likes of a Fiesta or Focus ST for work, even though my own daily car is a Focus RS. (Hopefully, one day they might let me drive the Ford GT. ;) )
I have also done driving experiences at Silverstone, as well as a rally driving experience on gravel and skid control. It all gives more understanding of car control and how to adapt for different situations and conditions.
 
whiteflyer said:
Someone pointed out your allowed a 10% error on your speedo, yes correct more than that could be an MOT failure, but if the cops catch you speeding I think your speedo reading will be irrelevant, over the limit is over the limit ( each police force has it's own allowable mph over before booking you)
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Speedo reading should be irrelevant from police perspective. They need to provide evidence of your real world physical speed being over the limit.

So if your speedo reads 10% over the limit, it would mean you can drive 64 on the speedo but not exceed the 60 speed limit physically. You won't get any trouble from police.

This is one of the reason (I think) why people brake for speed camera, they see they are driving 54 in a 50 variable speed motorway section. But in reality is that they were driving 49 with a 10% over-reading speedo. They brake, cause phantom traffic jam for miles.......


Doesn't matter speed camera or police, everyone should be comfortable being monitored for law enforcement at any moment. Don't change speed for speed camera!
 
nilagin said:
Fairly sure the speedo isn't even tested during an MOT. I've sat and watched all my cars have their MOT's for 40 yrs as well as my sons cars and my wifes car. The car only goes on rollers to test the brakes and even then they are only going slowly.
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My dashcam was on during an MOT a couple of years ago and the MOT screens did show the speed when the rolling road was used
Made interesting watching
 
The rolling road shows a speed because the brake test is done from (IIRC) 20MPH. If fitted, speedos must work but their accuracy isn't tested.
 
If you want to know what your Speedo shows, get a gps device, e.g. a phone, and a passenger, and monitor it over different stretches of road.

Mine has different overages at different speeds. Driving in Average Speed monitored sections it is clear that almost every other driver doesn’t know what speed they are really doing.
 
I've no idea if legally manufacturers have to have a physical way of reading the road speed, if not with all the new digital dashboards coming in I can't see a huge problem of then just using GPS for a more accurate speedo.
 
I use Waze GPS reading as my main source of speed info. I use the car's speedo as quick reference on less straight roads. When setting cruise control I always set so Waze value is at around the speed limit, if the condition allows.

I think the over reading is because of different wheel configurations. Wheel rotation is still the most accurate way to measure speed across all possible cases. GPS is only accurate on straight roads. Depend on GPS speed algorithm, some may only be accurate on flat roads.

It's easy to put in a self calibration software function that calculates car speed based on a large number of averages using GPS and takes into account of road gradient and steering angle. However, that's asking car manufacturers to do software across many subsystems (eg. GPS module, steering module and display module)....... if only there was a more vertically integrated tech company that happen to manufacture cars...... ;)
 
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GPS is also the speed you have just done, not what you are doing now.
 
Pound Coin said:
GPS is also the speed you have just done, not what you are doing now.
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Exactly. Wheel speed is still the best method. But it need to be constantly recalibrated, perfect job for the onboard computer over many averages.

If not changing speed, eg using cruise control, GPS speed can be used as reference, but need to remember its many limitations. To be honest, working within something’s limitation is the same with everything, more so with car assistive tech. Problem arises when people don’t take limitations into consideration.
 
whiteflyer said:
I've no idea if legally manufacturers have to have a physical way of reading the road speed, if not with all the new digital dashboards coming in I can't see a huge problem of then just using GPS for a more accurate speedo.
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The issue would be when you have limited number of satellites in view, eg when surrounded by large buildings, tunnels, forests, canyons etc.
Appreciate that it is not that often that you will encounter these, but the speedometer needs to work 100% of the time.
the ideas suggested above of a GPS calibrated speedometer sounds like a good idea, but may be a solution without a real problem.
 
nilagin said:
Driver inexperience plays a big part in error of judgement, not just inexperience in their driving ability, but also their cars ability. As a result, they can drive too fast or too slow.
Also you have to factor in the car itself.
How good are it's tyres, just because they have 6mm of tread, doesn't mean they have better grip than a tyre that has a softer tread and only 3mm of tread. It is all about knowing your vehicle respecting it and knowing its capabilities.
The problem is motorists who just drive from A to B with no appreciation of what they are doing or why they are doing it.
It is still possible to exceed the speed limit and still drive safely.
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wyx087 said:
If not changing speed, eg using cruise control, GPS speed can be used as reference, but need to remember its many limitations. To be honest, working within something’s limitation is the same with everything, more so with car assistive tech. Problem arises when people don’t take limitations into consideration.
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Oh, get a room you two ;)
 
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