Multanovas are wrong by
15kmh: scientists
From The West Australian
By Daniel Emerson
April 1, 2006
Serious questions have been
raised about the accuracy of Multanovas after a world-renowned radar
expert claimed the machines could be out by up to 15kmh if speeds
are measured while drivers are changing lanes.
Stuart Nixon, whose company was involved
with online satellite site Google Earth, claims WA motorists are losing
their licences and getting hit with fines because of errors in Multanovas
readings.
Key point of his research have the backing
of mathematics professors from several WA universities.
WA police admitted this week that readings
taken from cars which are changing lanes can be wrong.
Mr Nixon said the root of the problem
stemmed from the angle at which Multanovas were positioned relative
to the side of the road.
Multanovas are designed to be pointed
at the road at an angle of 22 degrees to the kerb. This allows operators
to calculate the speeds of cars in more than one lane. The angle also
means radar detectors have trouble detecting speed cameras.
Multanovas use a set mathematical formula
which takes into account the angle. However, the machines are unable
to deal with the extra angle created when drivers change lanes.
“It will read faster if you swap
lanes towards the Multanova and slower if you swap lanes away from
it,” Mr Nixon said.
“The error could be between 5 and
15kmh but more likely down the lower end, between 5 and 10kmh.”
He said he started investigating the
issue after receiving a fine while driving along Stirling Highway.
“It was certainly beatable but
it was going to be very big job to do because the police consistently
refused to release the Multanova manual,” he said.
The West Australian asked three mathematicians
to look into Mr Nixon’s claims. All said he was correct.
Officer-in-charge of police camera section
Sen. Sgt Carl Fisher admitted that a reading from a car which was
changing lanes would be inaccurate. The inaccuracy would be negligible.
“On most occasions the unit self-cancels
due to incorrect comparison readings over a split second,” he
said.
“We are aware of the issue and
if sighted on film do not prosecute.”
Police refused to provide examples where drivers had not been fined
despite being caught by a Multanova.
