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NEWS: Radar detector, police speeding
fine and laser jammer news 2002.
VEHICLE SPEED
MEASUREMENT II
LESLIE C L FELIX
13 Nalimba Avenue
Para Vista
SA 5093
Abstract
This paper discusses uncertainties and errors in vehicle
speed measurement and the legal implications of these.
It provides a proven method of measuring vehicle speed
over its working range, without the use of
extrapolation, which is conducted in a controlled
environment rather than on public roads.
Keywords: speed, speedometers
Introduction
Both federal and state legislation set standards for the
accuracy of speedometers installed in motor vehicles.
Unless these legislative provisions are compatible, and
prosecution policies recognise the accuracy achievable
by speedometers installed in vehicles, there is danger
that motorists could offend unwittingly. This paper will
discuss the interaction of the federal design standard,
individual state prosecution policies and the
performance of speedometers and associated testing
equipment.
The Australian Motor Vehicle Standards Act, (known as
the Australian Design Rules, or ADR [1]) sets
requirements for speedometers installed in vehicles to
be used on the road throughout Australia as:
“indicate the actual speed, for all speeds above 40
km/h, to an accuracy of ± 10 percent.”
State Legislatures have also set their own minimum
requirement. For example New South Wales Traffic Law [2]
requires that speedometers:
“indicate, when the vehicle is travelling at a speed in
excess of 50 km/h, a speed that is not more than 10%
less than actual speed”.
The individual State requirements are all worded
differently and may impose different constraints on the
performance of speedometers. However none change the
“10% less” requirement, which is a main contributing
factor to the system failure. This accuracy guide method
has severe limitations and is only used by persons with
a lack of understanding of measurement.
Uncertainties are an integral part of regulations
administered by the National Standards Commission, such
as those concerning the weighing of products in
commerce. Since there is a trend to base the level of
fines on exactly how much the speed limit is exceeded,
the policy should recognise the effect of uncertainty of
measurement and fall into line with other measurements
with financial implications. The ADR [1] should take
account of the requirements of the ISO Guide to the
Expression of Uncertainty in Measurement [3]. This
reference to uncertainty is an integral part of weight
measurement and is found in Australia’s adoption of
“Organisation Internationale De Métrologie Légale
Recommendation R111” [4].
There is a system that would enable drivers to reliably
determine if they are travelling within the posted
speeds limits. This paper will endeavour to prove the
accuracy and safety aspects of a test system that once
used, will enable the public to travel within the posted
speed and furthermore be expected to do so.
Monash University Research Notes
The Monash University Accident Research Centre published
research notes with the heading “Accuracy of vehicle
speedometer readings with respect to speed enforcement
tolerances” [5]. Table 1 gives a compilation of
statistics summarised in the notes.
Actual speed relationship to indicated speed in km/h
|
Actual speed relationship to indicated
speed in km/h |
|
|
Actual |
40 |
60 |
80 |
100 |
120 |
|
Max indicated |
43 |
64 |
83 |
108 |
130 |
|
Min indicated |
27 |
48 |
71 |
84 |
105 |
|
|
|
|
|
|
|
|
Table 1: Summary of results of speedometer tests carried
out by Monash University Accident Research Centre and
others between 1982 and 2001
The University used some collated results from other
sources and whilst the test methodology was not
described these results indicate either a failure by
manufacturers to meet the minimum requirement of the
relevant ADR [1], or that other mechanical factors are
affecting the results.
Speed indication errors and variations
Speedometers in vehicles respond to the rotational
velocity of the wheels. Errors and variations in vehicle
speed indication will then be due to either the
relationship between a rotation of the wheels and the
actual distance travelled, or to the errors in measuring
rotational velocity. The nature of the tyres contribute
the first type, and instrument errors the second.
Rolling road testing
The speed indication in a vehicle is tested by either
measuring the time to travel a known distance (measured
by numerous methods), or on an apparatus consisting of
rollers with known circumference and measurable
rotational velocity (a “rolling road”). Some instrument
repair companies merely “check” the odometer over a
distance and conclude the speedometer accuracy from this
data. Some have recently used GPS units. The latter
options require conducting tests on public roads.
Testing of speedometers should ideally be conducted
throughout the usable range as this eliminates the need
for extrapolation. There are obvious safety implications
if speedometers installed in vehicles are tested
throughout their range on public roads. However using a
rolling road for such measurements reduces the safety
issues and the latest computerised rolling road machines
provide a printout of the parameters tested.
Another machine that utilises rollers is the dynamometer
and these can be used to test speedometers. Most rolling
road testers are primarily a dynamometer. Its main
function is to introduce resistance to wheel rotation by
absorbing test vehicle energy into a load, and measuring
the force developed by the drive wheels. Care should be
taken when using a dynamometer that slippage is not
induced by the machine’s resistance. Some operators use
the loading to minimise hunting (the failure to maintain
a constant speed due to engine behaviour). Load
generation should be minimised as should tie-down
pressures. It is normal practice to chain or strap the
vehicle under heavy loading conditions for measuring
engine torque to avoid the vehicle climbing up and out
of the roller valley. In these tests, lateral
restraining of the vehicle was used instead of tie down,
since vertical restraining caused tyre distortion, which
can lead to an error in the region of 2 km/h. It would
be difficult to balance normal tyre load distortion,
aerodynamic and centrifugal force to a corresponding
offset for the rollers, because the forces are not
linear and combined to create a complex response curve.
At best only a “best fit” correction can be given.
Except where indicated otherwise, the tests described in
this paper were carried out on a free-running rolling
road, that is, without applying a load to the wheel
rotation. This machine held a current NATA accredited
certificate of accuracy. The measurements described in
this paper are traceable to an Australian National
Standard and have adhered to the requirements of ISO
17025 [7].
Tyre contributions
Errors due to tyres may be long-term (e.g. tyre type and
size), medium-term (e.g. tread wear), or short-term
(e.g. pressure and loading). The author undertook
measurements of both true and indicated vehicle speed
with varying tyre brands, wear and tyre fill pressures.
Inflation pressure:
Increase in pressure will occur as the tyre increases
with heating due to use. This pressure increase is as
much as 28 kPa (4 psi). An increase in tyre temperature
will increase pressure and cause the indicated speed to
be lower. The tyre inflation pressures referred to in
the following tests were hot pressures and should not be
confused with cold pressures settings recommended by
manufacturers. Tyre pressures were adjusted after the
tyre had reached operating temperature.
To examine how pressure affects the tyres, they were
initially inflated to 160 kPa. The first run at this
pressure was followed by tests in increments of 30 kPa
to a maximum tyre pressure of 280 kPa. One of the tests
was conducted with a standard tyre pressure of 190 kPa
and the equivalent weight of four adult males in the
car, all the other tests in this series were with one
adult male only. The deviations from true speed
occurring at indicated speeds of 30, 60, 80 and 120 km/h
were recorded. Three readings were made at each speed
and pressure, and mean of the readings were calculated.
Results of these tests are given in Table 2.
Speedometer error versus tyre pressure
|
Speedometer error versus tyre pressure
|
|
|
speed
⇓
|
280 kPa |
250 |
220 |
190 |
160 |
|
190+ load |
|
30 |
1.5 |
1.4 |
1.4 |
2.3 |
2.6 |
|
1.8 |
|
60 |
1.9 |
1.6 |
1.8 |
2.3 |
3.6 |
|
3.8 |
|
80 |
1.8 |
1.6 |
2.3 |
2.6 |
3.3 |
|
3.7 |
|
120 |
3.4 |
3.6 |
3.4 |
4.1 |
4.8 |
|
5.1 |
5.1
Table 2: Speedometer error variation with tyre pressure.
Brand and model:
Examination of model and brands were undertaken using 17
and 18inch rims with low profile tyres. Some 20
different tyre models were tested to consider variations
between brands. It was found that a variation of
speedometer reading of 1.5% resulted from the same
vehicle and speedometer calibration settings over the
twenty types.
Wear:
The change in the tread depth of a Dunlop Monza
205/65R15 tyre, from new through to the 1mm above wear
indicator bars, was measured to change the diameter by
12 mm (although the diameter change can be 14 mm if worn
completely). This is equivalent to a change in
circumference during its life of 2.0%.
Tyre distortion
On the face of it, the circumference of a tyre is
constant whatever the tyre pressure. However tyres
compress as the tyre surface changes shape when it meets
the road surface squeezing and then stretching each
portion of tread during a cycle so that the distance
travelled per revolution of the wheel changes. It was
found that a worn tyre does not compress to the same
amount as a tyre with new tread although smaller in
circumference. During these experiments it was found
that tyre growth under the influence of centrifugal
force was only significant when the tyres were
under-inflated and at speeds of more than 120 km/h. A
Dunlop 215/60R16 95V inflated to 240kPa was
roller-driven to 160 km/h and had expanded 3.5mm on
radius or approximately 1.1% of indicated speed. This
expansion increases with speed in an approximate
logarithmic fashion.
Experiments showed that a Dunlop Monza 205/65R15 tyre
fitted to a rim had an undistorted radius of 320mm at a
pressure of 220 kPa, a compressed radius of 295mm and, a
compressed radius of 290mm at a pressure of 190kPa. The
calculated circumferences for the three radii were
2011mm, 1854mm and 1822mm respectively. The distance
travelled in one rotation, for the compressed tyres was
measured to be 1966.5mm at 220kPa and 1908.0mm at
190kPa. The difference in the measured distances
travelled was 0.7% yet the radii differed by 1.7%.
Further clarification of this phenomenon would require
test throughout the pressure range for a number of
combinations of vehicle and tyres. The actual results
from direct comparison to laser and radar measurements
at speeds from 30 to 160km/h had indicated only a 0.7%
difference at 100km/h dropping to 0.4% at 160km/h. This
suppression may be a result of aerodynamic behaviour of
the vehicle. The results are given in Table 3.
|
Indicated |
30.0 |
60.0 |
80.0 |
100.0 |
120.0 |
160.0 |
|
Rollers |
29.7 |
57.3 |
76.3 |
96.4 |
116.1 |
157.3 |
|
Laser |
30.0 |
57.0 |
77.0 |
96.0 |
116.5 |
156.5 |
|
Radar |
29.5 |
57.0 |
77.0 |
96.0 |
116.0 |
156.5 |
Table 3: Comparisons of different methods of speed
measurement. Roller effects
When speed is measured using rollers the compressed
diameter of the tyre varies from the compressed diameter
of the same tyre on the road surface. This is due to the
rollers creating two curved surfaces rather than one
flat surface on the tyre (load surface area and shape,
or tyre footprint).
The effective circumference of a tyre on the road can
differ with brand, ply rating, belt type (steel or
nylon) and tread depth. This circumference variation can
be minimised when the vehicle is on the rollers by
increasing the tyre pressure. The required increase will
depend on tyre type, but early test results indicate it
is about 30 kPa.
Experiments on the tyre distortion with different
diameter rollers was undertaken starting with 203mm
(8.0 inch) to 266mm (10.5inch) in 12.5mm intervals Some
experiments are still being analysed that look at
leading edge roller speed sensing verses trailing edge
roller speed sensing. This plays a roll in the effective
diameter seen be the rolling road tester.
Tyre slippage for a sedan on the roller was measured at
a range of speeds using a strobe light and was found to
be minimal. Great care was given to minimise slippage
during the tests, and the measured slippage was less
than 100 mm over the test distance of three kilometres.
The total effect of slippage on speed accuracy was not
deemed as significant in free-rolling testing.
Instrument Errors
Systematic corrections that are not eliminated during
calibration or applied as a correction, will
contribute with opposite sign to the results of speed
measurement by a police pursuit vehicle. For
example, consider a police car tested at 100 km/h with a
reported error with new tyres of +1.5 km/h
(that is, the true speed is 1.5 km/h lower than the
indicated speed) and which eventually has tyres at
half wear equating to 1km/h. A motorist’s vehicle is
then perceived to be travelling 2.5 km/h faster than
actual. If the motorist has a speedometer error of -1.5
km/h and is travelling at an indicated speed of
100 km/h we can see that it has been measured to exceed
the speed by 4 km/h, enough to be considered
a breach of traffic rules. These errors created by, (a)
tyre wear, (b) not applying calibration corrections,
and/or (c) the roller-to-road anomaly, are critical to
the overall picture, since the accumulative affect
can be as much as 4 km/h. These three items were
intentionally not calculated in this first view of the
uncertainty assessments (subject discussion to follow)
since the corrections may or may not be deemed
as uncertainty components.
To calculate the uncertainty associated with a driver’s
knowledge of the true speed of his or her
vehicle, a review of the components of uncertainty
arising from interpretation of speedometer
indication, vehicle load, engine power management and
tyre behaviour was undertaken by the author.
The driver’s ability to accurately determine the vehicle
speed using an ordinary speedometer is affected
by:
*The intrinsic accuracy of the instrument (the residual
systematic error after calibration).
*Parallax error.
*Size of minor graduations (normally 5 or 10 km/h).
*Readability (usually one fifth of one minor
graduation).
Based on these factors uncertainty (expressed as 95%
confidence intervals) for a speedometer read to 2
km/h was as follows:
60 km/h is ±8 km/h
80 km/h is ±10 km/h
110 km/h is ±13 km/h.
A calibrated speedometer read to 2 km/h and tested with
certified speedometer testing reaches a better accuracy
than the ADR18.5.1.2, that is the accumulated
uncertainty described in this paper is less than the
±10% specified by ADR. The calculated uncertainty is
±4.9 km/h at 110 km/h without any account for tyre wear
and roller to road anomaly. This assumes that the
speedometer was either adjusted to read true or the
calibration correction was applied. Failing this, the
uncertainty must be calculated with an uncertainty
components added for the systematic errors.
The needle in an analogue speedometer will be about 2 mm
from the gauge face. This results in a parallax error,
which will depend on the position of the driver’s
dominant eye. The maximum error derived from
experimentation was less than 2 km/h. With the advent of
liquid crystal displays with either synthesized analogue
or numerical readout, parallax problems are not an
issue. On the other hand rounding of the displayed speed
may create errors but these would be less than 1 km/h.
Analogue instruments display information by indicating
with a needle or a pointer. The graduations on the
display face limit the precision of the instrument
readability. With a minimum division of 5 km/h and a
needle width of the equivalent of 1 km/h, resolution to
a fifth of a division or 1 km/h can be expected.
Examples of the application of this convention can be
found in Australian Standard AS1349[6]
Since infringements can occur in just a few metres, we
investigated other sources of speed control and
measurement and found a significant problem with smaller
vehicles. Measurements with an air-conditioned
four-cylinder vehicle showed a 5km/h variation in speed
with the air-conditioning compressor cycling. This
variation is created by the driver compensation for
power fluctuations by his efforts to maintain constant
speed. Policy makers may wish to include this in the big
picture.
Calibration of the testing machine
The measurements of the roller diameters and rotational
speed gives a standard uncertainty component of less
than 0.1 to 0.3 km/h between the speeds of 30 and 180
km/h. The stability of performance of all the roller
machines tested throughout most of Australia over the
last six years has been in the region of ± 0.2 km/h.
Plotted roller wear on the Adelaide based unit was less
than 0.01% over six years.
Police tolerances for speed infringements
The inconsistency between Australian States in their
tolerance of small infringement of speed limits means
that there is no single system in use. The most widely
used system is the decade method. The posted speed limit
can be exceeded by 9 km/h eg 69 in a 60km/h zone (89 in
80 km/h zone etc) and incurs a fine if 70 km/h is
detected. This method was introduced to compensate for
the ADR 18.5.1.2 speedometer error of ±10%.
One State has recently introduced a 3km/h tolerance,
since their detecting equipment carried an uncertainty
in the region of ±2 km/h. This system has the implicit
assumption that the drivers must not exceed the speed
limit regardless of measurement errors and the onus is
upon the driver to ensure that they comply with the law
irrespective of accuracy of their speedometer.
Discussion
Achievable aims:
The statistics collated by the Monash University, the
police departments, the Royal Automobile Association and
myself, indicate that a high proportion of speedometers
are set to read 3 km/h high to minimise liability and
supposedly to compensate for possible drift. There has
been no response from manufacturers confirming this
practice. The application of this offset does not
improve the accuracy of speedometers. The latest
manufactured vehicles have an accuracy of 3% or better,
of reading with one brand offering an adjustable version
correct to within 2% of full scale. In the first
instance, the use of “3%” is an archaic method of
describing accuracy and creates a distorted view of the
errors expected. Statistics have shown that ADR [1]
should be amended to read: “an accuracy of ±(0.65% of
full scale + 1.75% of reading)”,or “±(1.5 km/h + 1.75%
of reading)”.
This would ensure that the tolerance does not limit the
lower values to impossible accuracies or the upper value
becoming too large.
Tyre behaviour:
The tests conducted were not intended to measure
individual effects of tyre behaviour on speed but was a
measure of an overall effect. The “lumping” of the tyre
effects was purely to extract expected overall
variations in speed measurement.
Tyre wear and low fill pressure just resulted in a
higher indicated speed, which may not be of concern in a
motorist’s vehicle, but in a police vehicle will result
in a high reading of the speed of motorists. A worry for
motorists is the fact that tyre pressure increases from
cold to hot, lower indicated speed.
Improved method:
With the adoption of the suggested changes to the design
rules, and with roller anomaly taken into account, we
can then address the policy of dealing with the error
caused by tyre wear, so that the uncertainty can be
calculated considering all significant components. The
author suggests taking measurements for the tyre wear at
the half wear point since a tread depth at time of test
can be obtained and results of the speedometer test
mathematically corrected to the half wear point. The
tyre wear can then be included in the uncertainty to
reflect results by tyres wear being other than half
worn. The combined uncertainty components mentioned
earlier and these latest additions were calculated to be
±6.7 km/h for a Dunlop Monza 205/65R15 tyre at 110 km/h.
No mans land:
In some Australian States road works and children’s
crossing zones are automatically classed as 25 km/h
zones. As the wording of the design rules (ADR 18.5.1.2)
does not call for any accuracy for speeds below 40 km/h,
the driver has no assurance of the vehicle’s true speed
in these zones.
Driver’s responsibility:
Other errors that have been attributed to outside
interference (for example incorrect tyre size fitted, or
differential ratio altered), or a deviation from
manufacturers specifications are a separate issue. With
vehicles made to the amended ADR as suggested above in
paragraph “Achievable aims”, the uncalibrated
speedometer would have a lower calculated uncertainty of
speed measurement and can be expected to perform within
a smaller infringement tolerance.
Breach of natural justice:
The calculation of uncertainty associated with speeds up
to 120km/h shows that the decade method used by police
forces allows infringement notices to be issued to
drivers travelling within the region of uncertainty. The
issuing of infringement notices using the 3 km/h
tolerance system can be even unfair to drivers who use a
speed-measuring instrument conforming to Australian
design rules.
A temporary measure:
A suggested policing policy is to allow 7 km/h at speeds
of up to 50 km/h and an additional 1 km/h for every 10
km/h of speed up to 110 km/h speed. This policy will
prevent infringements notices being issued for the
region of uncertainty and therefore should not be
legally challengeable. This policy of expanded
tolerances would only be an interim measure to correct
the present situation, prior to public testing
facilities being introduced.
The solution:
I believe that this paper lays the groundwork to give
the Federal Government, State Governments, State Police
Forces and motorists the tools to operate motor vehicle
speed control measures correctly and fairly. If all
recommendations are accepted, a fixed tolerance of 7
km/h (or a sliding scale of tighter constraint but more
cumbersome to apply) can be used without compromising
the motorists and afford them their right to an accurate
form of speed measurement. However this policy assumes
the application of calibration offsets to correct the
speed value. The process of testing and calibration of
rolling road testers that is traceable to a national
standard must be made publicly available. A series of
approved testing stations should be available so that
motorists can confirm their speedometer accuracy and
drive accordingly.
Acknowledgements:
I would like to thank the following people and companies
for their assistance in producing this paper.
Royal Automobile Association of South Australia for the
use of testing equipment.
R Laslett (retired) of S.A. Police Traffic Technical
Support for Encouragement and guidance.
J Lipman Traffic Technical Support NSW Police, for
duplicate testing to expose systematic errors.
Injection Perfection NSW, for duplicate testing to
expose systematic errors.
South Australia Police Force for road to roller
comparisons
J Tapping for his editorial assistance.
Abstec Calibrations Australia®
For my employer’s continued support
References:
1 The Australian Motor Vehicle Standards Act 1989,
Design Regulation 18.5.1.2
2 New South Wales Traffic Law, Ninth Edition, Road
Transport Regulation 1998 Section 41.
3 ISO Guide to the Expression of Uncertainty in
Measurement. International Organisation for
Standardisation, Geneva, 1993 ISBN 92-67-10188-9
4 Organisation Internationale De Métrologie Légale”
Recommendation R111 titled Weights of classes E1, E2,
F1, F2, M1, M1-2, M2-3 and M3
5 Monash University Accident Research Centre, “Accuracy
of Vehicle Speedometer readings with respect to speed
enforcement tolerances”.
6 Australian Standard AS1349-1986, Bourdon tube pressure
and vacuum gauges, Section 1.3 (Definitions), 1.3.4
(Scales and scale markings).
7 Australian Standard ISO/IEC 17025-1999, “General
requirements for the competence of testing and
calibration laboratories.”
Height kills
From The Association of British Drivers
By Andrew Bent
2002
The traffic engineer was quite pleased with himself, he
had finally managed to stop the local bus drivers trying
to take their double deckers under the low bridge under
the railway, so Councillor Prescott might finally
concede that he knew what he was doing. But as he
entered Prescott's office he saw that the councillor was
in an ominously thoughtful mood.
'I see we've had a reduction in accidents in Railway
Terrace' said Mr Prescott, 'Yes' said the engineer,
anxious to demonstrate his success, 'You see I did a
survey and found that the maximum safe height under the
bridge was 12'2", so I arranged for some warning signs
to stop anyone taking a vehicle more than 12' high...'
But the Councillor had already lost interest. 'I've been
studying some statistics' said the Councillor (the
engineer winced, Councillor Prescott's grasp of
mathematics was notoriously shaky) 'and it seems that
when those new warning signs went up the average height
of vehicles using Railway Terrace fell by 9 inches',
'Well, yes..' replied the engineer, 'and accidents
dropped by 18%' continued the Councillor triumphantly'.
The traffic engineer tried to figure out where this was
leading, 'Do you realise what this means? Every inch of
average height reduction leads to a 2% reduction in
accidents! All we have to do is alter the warning signs
to read 11' and accidents will drop by another 24%!'
His head spinning, the traffic engineer tried to reason
with the Councilor, 'but if a 12 foot vehicle can get
through perfectly safely, what is the point in imposing
extra restrictions?' Councilor Prescott was having none
of this, 'you don't seem to understand, Height Kills, if
every inch of height reduction causes a 2% drop in
accidents, surely we must have a height limit reduction
program, let's speak to the bus company and see if they
can lower the single deckers somehow.'
The traffic engineer thought quickly, there was no point
in trying to explain the facts, Councilor Prescott
always regarded knowledge of road traffic and accident
causation a fatal disqualification for making decisions
on the subject, but there was a possible way to turn the
situation to advantage. 'There is another low bridge,
under the disused railway in Beeching Close, where
lorries do sometimes get stuck, but I haven't had the
funds to tackle the problem before, I suggest that
should be the first priority for the height reduction
program'. Councilor Prescott agreed and the traffic
engineer set off for Beeching Close with measuring rod
in hand.
At first it wasn't clear why there was a problem at this
particular bridge, there was already a height
restriction of 7 feet, so why on earth were drivers
ignoring it? After an examination of the bridge the
reason became clear, the maximum safe height was over 14
feet. On receiving a recommendation that the 7 foot
height limit was unrealistic and should be raised,
Councilor Prescott was apoplectic, 'lorries are getting
stuck because they are too high' he yelled, 'surely the
limit needs to be lowered'. The engineer tried to point
out that it was precisely because the limit was
obviously ludicrous that it was being ignored, and that
raising the limit would increase compliance, but the
Councilor did not understand. 'In Railway Terrace,
reducing the height reduced accidents, therefore Height
Kills' he argued, 'surely raising the limit in Beeching
Close will increase average heights, therefore increase
accidents,' 'But it isn't the average height that
matters' the engineer tried to point out, 'a 14 foot
limit will be taken seriously and will reduce instances
of excessive height, therefore reduce accidents, whether
the average goes up or down is totally beside the
point'. 'But Height Kills' bellowed the Councillor, 'no
it doesn't' the engineer bellowed back, of course he
should have said 'not necessarily' but this is not an
easy thing to bellow.
'How can you say height didn't cause this?' Councilor
Prescott produced a press photo of the mangled remains
of a double decker wedged under the Railway Terrace
bridge and dropped it on the desk with the air of one
producing the ace of trumps. 'The point was that the
height was excessive for the situation, it is excessive
height that causes the problem, not height itself' the
engineer protested, but the Councillor wasn't listening,
'I've already decided to introduce a height reduction
program, reducing all existing height limits by a foot,
if this succeeds in reducing heights, I'll introduce a
host of new height limits, if it doesn't I'll reduce the
limits further until it does....'
The engineer stopped listening; once Councillor Prescott
had made up his mind, there was no point in giving him
the facts.
I guess the same arguments could be used with speed
limits, but that would be silly wouldn’t it! ED
Fatal flaw with speed cameras
From The Sunday Times
By Paul Murray
June 02, 2002
“Speed cameras undermine public confidence in traffic
enforcement.
Cabinet’s decision to terminate speed cameras reflects
this government’s commitment to fairness and to the
safety of the public.
Direct, visible policing and immediate intervention is a
much more effective deterrent to speeders than getting a
speed camera ticket in the mail.”
Does that sound like something you’re likely to hear
from the Gallop Government?
They were the words used by British Columbia’s
Attorney-General Geoff Plant when he ended the Canadian
province’s speed camera program – known there as photo
radar – last year.
His official statement added that a police officer on
the scene was in a much better position to determine
whether a speeding driver also was guilty of other
offences such as drinking-driving or driving without a
proper licence.
And so BC scrapped the money-making machines and put
more cops back on patrol. The provincial government had
worked out what is now becoming apparent in Australia.
Speed cameras are great revenue raisers – but they are
ineffective at cutting the road toll.
BC followed the provincial Canadian government of
Ontario in dropping speed cameras. When Ontario made the
move, its then premier Mike Harris said Multanovas –
that’s what they were using were “a government cash
grab”.
Speed cameras are on the nose all over Canada. In
Alberta, Calgary’s police union actually backed a
candidate for mayor of the city on the basis that he
wanted to do away with Multanovas.
Al Koenig, president of the Calgary Police Association,
was quoted in the Calgary Sun as saying a Multanova was
a cash cow not a road safety device.
You have only to look at our latest state Budget to find
out why speed cameras should be axed in Western
Australia – but won’t be.
The Budget, papers show that income from speed and red
light cameras jumped $10 million last financial year to
$49.2 million. This will rise again significantly next
year because it did not include a full year of the lower
“60 means 60” tolerance level which boosted the current
figure.
While the Budget shows this alarming revenue increase,
it also makes an even more startling projection. The
road toll will rise in the next financial year from nine
deaths per 100,000 people to 10.
That equates to 18 more deaths on our roads next year,
according to calculations by the Royal Automobile Club.
So much for the Government’s touted road-safety reforms,
the effectiveness of speed cameras and its target of six
deaths per 100,000 by 2005.
Treasury doesn’t swallow the rhetoric. What it sees is
more cash from speed cameras and more deaths on the
roads.
And what about time spent policing road safety? In
2000-01, the police spent nearly 1.6 million hours on
the job. The new Budget provides for 1.53 million hours
– that’s 68,000 man hours fewer in a year. And that’s
186 man hours per day fewer on traffic management and
road safety than two years ago.
Fewer cops on the road, more money from Multanovas.
Worse still, the Gallop Government has been caught
reneging on its promise to use all the speed camera
revenue on road safety. Its own figures show that $33
million of the $49.2 million was spent on what is called
a road-enhancement program – and most of that is just
routine maintenance. A complete con trick.
So why wouldn’t the road-safety picture look grim? We
pinch most of our road trauma strategies from Victoria –
and have a look at its record. It’s really on the speed
camera cash drip. That latest Victorian Budget shows
that speed camera use in Victoria has risen from 50,000
hours of use at its inception in 1994-5 to 1.2 million
hours. With it came explosive revenue increases from $96
million to $337 million.
And the road trauma record over those nine years? Deaths
on Victorian roads went from 378 in 1994-5 to 448 last
year – the highest in a decade.
Over the past financial year, speed camera revenue went
up by $131 million and the road toll increased by 44.
So how do you paint a picture from that of a road-safety
strategy based on speed cameras? It’s not possible.
And now there has been a split in the bipartisan support
for speed cameras in Victoria.
The Opposition transport spokesman there, Geoff Leigh,
says the Barracks Labor Government is addicted to speed
camera revenue. And he says police are being used on the
roads as tax collectors.
It’s time there was a bit of political truth telling in
this state about our flawed road-safety strategy. A bit
of realism in the evaluation of speed cameras.
It might just save 18 lives – or more.
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