Average Speed Cameras to Police UK Rural Speed Reduction

talisman56 · Occasional Visitor Joined: Oct 13, 2007 Posts: 1

Do the people proposing the blanket speed reduction to 50mph really think that the idiots that ignore the 60mph national speed limit would take notice of the new one?

What really needs looking at is the current zeal of local councils for apparently arbitrary reductions of rural roads to 40 and 50 mph (signposted, of course, with little yellow signs with the relevant speed limit sign with a camera sign underneath). I'm getting really peed off with having to stick to 40mph on a dead straight and level road just because some 'elf and safety zealot has decided that because the local XR3i brigade have managed to somehow wrap their cars around trees that we all need to slow down... Confused

253 · Posted: Fri Mar 13, 2009 8:06 pm Post subject:

magandyuk · Occasional Visitor Joined: Aug 12, 2006 Posts: 1

As the most efficient speed of the average car is around 56mph, surely reduction of the speed limit from 60 to 50 will just increase emissions and increase fuel consumption?!

What we need is to take CCTV to the extreme, with all drivers having the option of a subsidised, gps linked(for speed capture) dashboard mountable video camera to record other drivers' poor driving and an official website (a la YouTube stylie) to receive all video uploads for subsequent prosecution. No more arguments over blame. Confused

Andy M, BEng.

DennisN

DarrenR21373 · Posted: Sun Mar 15, 2009 12:21 am Post subject:

I seem to recall reading something written by an Automotive Engineer (who obviously should know more about these things than me/us).

Basically, he was of the opinion that the most economical speed to drive at is where the engine hits its peak torque in top gear - which, in my car (SEAT Leon 1.9 TDi), would indeed be 60MPH (2,000 RPM).

In fact, I tried an experiment driving back from Coventry to Surrey - reset the trip computer, set the Cruise Control at 60 and averaged 78 - 82 MPG over about 50 miles - not bad, considering my car isn't really an eco-box! I've never got near that driving at 50 - due to having to constantly change up and down between 4th and 5th gears for gradients...
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Drive carefully; the Government needs all the Taxpayers it can get.

navver · Posted: Mon Mar 16, 2009 8:44 pm Post subject:

Many years ago when I wuz at ingineering college we did an experiment on an engine and the peak ENGINE efficiency was at the rpm at which the engine delivered maximum torque.

The power needed to push a car along at a constant speed on a level road varies as follows:

Directly proportional to the speed for rolling resistance of tyres etc.

Proportional to the square of the speed for friction in wheel bearings, transmission etc.

Proportional to the cube of the speed for aerodynamic drag.

So as speed increases from 0 mph, energy losses from these 3 items increases in varying amounts, whilst engine efficiency increases until the point where a balance is achieved between engine efficiency and energy losses.

If I had my slide rule handy I'd tell you what that speed is.

The most economical speed will vary from car to car as they all have different amounts of the various components.

Oddly enough, many larger cars are more economical at speed than the smaller ones as they have less aerodynamic drag.

Privateer · Posted: Tue Mar 17, 2009 6:50 pm Post subject:

DennisN · Posted: Tue Mar 17, 2009 9:40 pm Post subject:

Pocketgps · Posted: Sat Mar 21, 2009 1:31 pm Post subject:

This petition seems to be loosing momentum Embarassed

Any body not signed can HERE

This is not my petition, but it does seem silly not to sign and keep it going.

	PocketGPS
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