Speeding driver blames indicators | Northland News | Local News in Northland

Dean Dorricott thought his car's speedometer reading was 5km/h  too slow.

So he compensated by speeding up.

It seems he was wrong.

Last December, the Whangarei electrician drove past two roadside indicators at Onerahi.

They suggested he was travelling at 45km/h, when his speedo read 50km/h.

Mr Dorricott, 59, thought this meant his car's speedometer was inaccurate by 5km/h.

Until he got a speeding ticket.

Mr Dorricott is challenging the ticket, and says the roadside indicator put him wrong. He had been towing an empty trailer on State Highway One at Ruakaka.

The speed limit for cars towing trailers is 90km/h.

"My speedometer indicated 100km/h and considering the error on my speedo I should have been driving at 90km/h.

He was stopped by police who said he had been travelling at 103km/h.

"I explained I set my speedo against the speed indicator sign and made an allowance for the error, but they gave me an $80 ticket and 20 demerit points."

 Mr Dorricott sent a letter to police headquarters disputing the ticket. He received a reply telling him "electronic roadside indicators are not tools which you should use to calibrate the speed of your vehicle. You need to gauge the speedo in your vehicle to gauge speed".

Mr Dorricott said the signs were misleading.

"They're telling people that in order to drive at the correct speed, they need to add 10 per cent - it's almost entrapment."

"Perhaps they should have a sign telling people they're not accurate."

RoadSafe Northland co-ordinator Gillian Archer said the aim of the signs was to warn people they were over the speed limit, not that there was something wrong with their car. "To be driving like that ever since is irresponsible."

If Mr Dorricott thought there was a problem with his speedo he should have had it repaired, Ms Archer said.

There was no way he could prove the indicators weren't correct, she said.

"If a line of cars are doing different speeds, the speed on the sign is not necessarily the speed your car is doing."

The signs were a reminder to motorists to check their speed and Mr Dorricott was "drumming up some publicity to get off his fine," Ms Archer said.

Mr Dorricott said he had checked his speedometer with and without the presence of other traffic and was prepared to take the matter to court.

Whangarei District Council information shows the cream coloured indicators were installed in 2008 at Onerahi Rd, Three Mile Bush Rd, Ngunguru, Okara Dr, Tarewa Rd, Kioreroa Rd and Vinegar Hill.

Two electronic signs are rotated between the eight sites. The signs measure the speed of the driver between 50 and 100 metres in front of the sign, which may indicate a faster or slower reading than a driver's perceived speed.

Council media relations adviser Ann Midson said Mr Dorricott was the first person the council was aware of who had driven faster because they thought the signs indicated a faulty speedometer.

"Most people in traffic safety would agree it's always good to take a conservative approach when faced with conflicting data."

Northland police communications officer Sarah Kennett said motorists should stick to the speed limit.

 New Zealand Transport Agency spokesman Andy Knackstedt said vehicle speedometers were seldom 100 per cent accurate.

"In nearly all cases any speedometer inaccuracy will be on the side of over-reading  speed - manufacturers do this deliberately on standard production vehicles."