31 mph in a 30 mph and your booked mate!!

[Phil]

Hi everyone,

I was flicking around the radio earlier today and caught the tail end of a story. Something about police been told to book you, if your doing 31 mph in a 30 mph zone.

Is there any truth in this?

If so, does anyone know how to get from the city centre to Kildare without travelling on a 30 mph road? ;)

No seriously, if anyone has any more information, could you please pass it on.

[WhipLash]

Hi Phil.

Previously the supposed 'grace' margin for speeding offences to kick in was after about 10%. So if you were doing 33MPH in a 30 zone, then that was usually seen as being tolerable. Although I'd imagine that at higher speeds the margin was lower - e.g. you may get done doing 77MPH in a 70 zone.

As far as I know, this 10% margin existed to allow for variances in speedometre calibrations. It also took into consideration the variances on the speed detecting instrument itself.

It would be interesting to know the average variation in modern cars, and also of the varies speed detecting equipment the Gardai use. I'd say that you'd have a strong case to make if your speed was within the combined variance levels and you had been penialised for speeding.

Does anyone know the *real* rule here then? Any other info available?

[WhipLash]

After doing some investigation into this subject, I've come to some interesting thoughts:

1) Speedo's aren't 100% correct - fact.
2) A speedo can be affected by under/over inflated tyres, leading to incorrect speed readings.
3) Larger tyres than those that come standard with the car lead to lower speedo readings than the car is actually driving at - take care if you've upgraded your wheels!!!
4) The Equipment used by the Gardai has a +/- 1 MPH variance on readings - this is stated by the manufacturer.


With points 1) and especially 4) above, I find it hard that this zero-tolerance will actually work. I can easily see this going to court and been shot down.

Also, in some countries the police force have to have the equipment calibrated every so often to ensure that the readings are accurate (ie within the +/- 1 MPH variance). Failure to do so means that fines are null and void. That could be another potential loop-hole - but a legal one at that rather than a flakey process (i.e. the incorrect amount on the cheque). I reckon that the Gardai would need to have a proper record of all speed detecting equipment being calibrated periodically if a case went to court.

[Phil]

Hi Whiplash

More news just in.

You can read what Robert Taylor, Managing Director, RAC Ireland, had to say regarding the zero tolerance speeding order

Click here to go to news story (http://www.eforecourt.com/body.htm/pid/590/catagory/general)