Speed limit on motorways.

[winjim]

I thought by law the speedometer had to read over?

Shaun

If that's the case then I should probably try and get hold of S Yorks police's mobile speed camera calibration records, with a view to reclaiming the 85 quid I spent on my speed awareness course.

 

[Milzy]

Speed limits should be lowered to save lives, fuel and lower pollution.

 

[Deleted member 1258]

I thought by law the speedometer had to read over?

Shaun

A speedo must never show less than the actual speed, and must never show more than 110% of actual speed + 6.25mph. So if your true speed is 40mph, your speedo could legally be reading up to 50.25mph but never less than 40mph. Or to put it another way, if your speedo is reading 50mph, you won’t be doing more than 50mph but it’s possible you might actually only be travelling at 40mph.
To ensure that they comply with the law and make sure that their speedometers are never showing less than true speed under any foreseeable circumstances, car manufacturers will normally deliberately calibrate their speedos to read ‘high’ by a certain amount.

 

[midlife]

The regs indicate that the speedometer can never give a lower speed reading than the actual speed so manufacturers generally make the speedometer give a higher reading so that you are actually going slower than you think...

Shaun

The amended Road Vehicles (Construction and Use) Regulations 1986 permits the use of speedometers that meet either the requirements of EC Council Directive 75/443 (as amended by Directive 97/39) or UNECE Regulation 39.[11]
The Motor Vehicles (Approval) Regulations 2001[12] permits single vehicles to be approved. As with the UNECE regulation and the EC Directives, the speedometer must never show an indicated speed less than the actual speed. However it differs slightly from them in specifying that for all actual speeds between 25 mph and 70 mph (or the vehicles' maximum speed if it is lower than this), the indicated speed must not exceed 110% of the actual speed, plus 6.25 mph.
For example, if the vehicle is actually travelling at 50 mph, the speedometer must not show more than 61.25 mph or less than 50 mph.

 

[arranandy]

Motorway speed limit over here in the Netherlands is 130kph (81mph) and It feels much safer than driving in the UK at 70mph. Mind you the road surfaces are better and, in general, the standard of driving is better

 

[Tin Pot]

Decrease number of drivers, increase motorway speed limits.

 

[mustang1]

Let the train take the strain.

Train gives my brain a strain.
Endless delay even though I pay.
They can get the ticket and stick it.
Where the sun don't shine, this poem (mostly) rhymes.

 

[mustang1]

I thought these speed limits were only suggested limits. As long as you are rich enough to pay the fines then you're ok, so long as you don't go over some limit where you get banned.

 

[Tin Pot]

Train gives my brain a strain.
Endless delay even though I pay.
They can get the ticket and stick it.
Where the sun don't shine, this poem (mostly) rhymes.

Internet maps tells me it'll take 11hrs to get to Wimbleball by public transport(!)

5 hrs to Taunton, then I could ride if I didnt have family with me so I suppose a taxi makes it 6hrs.

 

[winjim]

Speed limits should be lowered to save lives, fuel and lower pollution.

I'd be happy just to see the ones we currently have properly enforced. We have the means, but not the will.

 

[tommaguzzi]

Speed limits should be lowered to save lives, fuel and lower pollution.

how does lowering speed lower polution?
if the vehicle is traveling slower the journey time is greater, therefor it's engine is running for longer producing just as much if not more polution.

 

[Tin Pot]

how does lowering speed lower polution?
if the vehicle is traveling slower the journey time is greater, therefor it's engine is running for longer producing just as much if not more polution.

No, the engines are less efficient at higher speed and burn more fuel for the same journey.

 

[Slick]

[QUOTE 4810967, member: 9609"]at 90 mph you may only be getting 25 mpg
at 50 mph you could be getting 80 mpg

wind resistance increases exponentially with speed. double your speed and wind resistance increase 4 to 8x[/QUOTE]
Mmm, not sure where you get your mpg figures but it certainly doesn't match the car I drive.

 

[swansonj]

I had a work colleague that reckoned you can fool the average speed cameras by changing lanes between them.
"So, the system records the times you passed the cameras, works out the average speed, recognises the numberplate and then sends out a NIP to the cars registered address when you've broken the limit, with barely any human input, but can't figure out you've changed lanes. Let me know how it goes..."

Doesn't work, the computers still recognise the registration plates no matter what lanes you are in. You will still get a speeding ticket.

I believe that when average speed cameras were first introduced, they were perfectly capable of recording cars that changed lanes, but there was a drafting oversight in the licensing that resulted in a loophole such that they weren't legally allowed to be used as evidence when a car changed lanes. That is possibly what your colleague got hold of a garbled version of. I believe that loophole has been closed.

 

[tommaguzzi]

i have a nissan mpv according to my car's readout it does 48 mpg at 70 mph around town it drops to 28 mpg.