Links to world ISA projects
First International Conference on Intelligent Speed Adaptation: Sydney 10 Nov 2009.
Low Range Speeding and the Potential Benefits of Intelligent Speed Assistance (600K PDF preprint of conference paper) - findings confirmed in
Casualty crash reductions from reducing various levels of speeding (2011 CASR report)
Mar 2012 Pay-How-You-Drive car insurance will reward drivers who obey speed limits
Sep 2012: SpeedAlert Live now available for free for iPhone and Android.
Dec 2012: ISA in the USA: 5 Dec 12 IIHS Status Report: Intelligent speed adaptation devices can reduce speeding.
Beware of some brands of sat-nav that have a speed limit sign displayed
on the packaging. The speed limit database is very limited for some
devices (eg around schools and speed cameras) or, worst still, has to
be set manually by the driver. To my knowledge only the SpeedAlert
system has an extensive nationwide database and time-based school zones.
Update June 2009: The latest Navig8r - the G35 has the option for an analogue
speedo display - a dynamic speedo that clearly shows the current speed
limit. I also like the scale of the speedo, with a maximum speed of
120km/h. Video of demonstration (10Mb WMV)
Update October 2010: SpeedAlert now available on the iPhone as part of the Metroview Navigator app
December 2011 - SpeedAlert still available in a low-cost sat-nav
Post-publication notes, news
I first became aware of the remarkable
road safety benefits of reducing traffic speeds while researching a
project for the NSW Roads and Traffic Authority in 1996: Speed Control Devices for Cars
. Subsequent presentations have included:
points that motorists should be aware of are:
1. Half of all fatal accidents occur at
an impact speed of less than
55km/h. "Low speed" collisions can be deadly. This is due to Newton's
physics and the frailty of the human body.
2. Every 5km/h
above the speed limit doubles the risk of being involved
in a casualty accident. In a 60 zone, travelling at 65km/h doubles the
risk and travelling at 70km/h quadruples the risk.
For several years I have been calling for measures that assist
motorists comply with speed limits (and, incidentally, avoid speeding
tickets). GPS navigation technology is bringing that closer to reality.
One of the key findings is that, for a given set of
road conditions, there is a optimum maximum speed, above which the risk
of fatal accidents can be expected to rise more or less exponentially.
This risk is
largely due to restricted sight distances and the corresponding time
to recognise that a hazard is present and decide to take avoidance
- the risk is not greatly affected by driver ability or vehicle
Separate lines of road safety research have produced the similar
The clear message is that it is very important that speed limits
and enforced, according to the actual conditions so that they do not
the optimum level for those conditions, otherwise a disproportional
in fatalities can be expected. It is not advisable to set speed limits
to the speeds perceived as "safe" by motorists (for example, 85th
traffic speeds) - given suitable input, "expert" computer systems are a
better way to decide on appropriate speed limits - see
- Swedish research (Nilsson 1993) into
speed limit changes throughout the developed world suggests a fourth
power relationship between mean traffic speed and the proportion of
fatal crashes. A 3% reduction in mean traffic speeds can produce a 12%
reduction in fatal crashes.
- Recent analysis, by the Insurance Institute for Highway Safety
, of speed limit changes within some states in the USA shows a 15%
in fatalities per vehicle kilometre travelled for states that have
speed limits. FAQ
- The NHMRC Road Accident Research Unit has prepared a report Travelling Speed
the Risk of Crash Involvement which found that in a 60km/h speed
area, the risk of involvement in a casualty crash doubles with each
increase in travelling speed above 60km/h
Big Brother? There is no surveillance
used in the ISA system, which is under trial in several countries. GPS
is simply used by the system WITHIN THE VEHICLE to determine its
geographic location. A digital map then provides the driver with the
posted speed limit. No one but the driver knows the location and speed
of the vehicle (although, with some systems, trips can be recorded for
9 Feb 09 Canberra Times (reprint): A new attitude to speeding needed
Response to the article and comments...
The problem is that most motorists do not appreciate the
extra risks involved in travelling just a few km/h over the speed
limit. Most think that the risk of a casualty crash is doubled if you a
travelling at least 25km/h over the speed limit. The truth, which is
based on the unbreakable laws of physics and the frailty of the human
body, is that in urban areas the risk is doubled for each 5km/h over
the limit. So travelling at 70km/h in a 60 zone quadruples the risk of
a crash in which someone is hospitalised. As a result, about 15% of
road fatalities could be prevented if the (large) group of motorists
who routinely travel at up to 10km/h over the limit were encouraged to
obey the speed limits.
It is difficult, if not impossible, for enforcement methods like fixed
speed cameras to have an effect on this "minor" speeding. An added
problem is that even motorists who want to obey the speed limits (to
keep their life, licence or livelihood) have difficulty doing this in
modern cars on city roads. This is where Intelligent Speed Assist comes
into its own. The system has a very simple function, backed up by very
clever technology. It knows the location and speed of the vehicle and,
from an on-board database of speed limits, it can alert the driver to
speeding. I have been using an ISA device in Sydney since mid 2006 and
have prepared papers for international road safety conferences.
Participants at these conference often express disbelief that Australia
is leading the world with this technology. Sometimes they claim there
could be negative outcomes, such as always driving at the speed limit
rather than to the conditions, but numerous ISA trials around the word
have shown these claims are unsubstantiated.
Yesterday the Sunday papers in Sydney had a Harvey Norman brochure
advertising the Navig8r M35 unit for $148. This unit, as described by
Crispin, can be run exclusively in speed alert mode displaying just the
speed limit and current vehicle speed. This avoids the distraction of
the navigation map, which is rarely needed for regular driving (the map
is instantly available by touching a button the screen but I would like
to see any sat-nav device require the vehicle to be stationary before
it accepts any touch screen input).
In my view, every novice driver should be issued with such an
intelligent speed assist device for the first year of driving. Maybe
the resulting responsible driving would rub off on the rest of us.
"The first reaction to something that challenges your beliefs is denial" - Rev Thomas Goodhue
Links to ISA projects around the world
described on the Internet (for information - not endorsement)
Updates and news (most recent at bottom)
- 28 May 1998: Prof Murray Mackay from the University
of Birmingham has estimated that the "delta V" for the crash which
Diana, Princess of Wales, was about 80km/h - not double this speed as
speculated by the media. Note this was an offset crash so the intrusion
greater than if the crash forces had been distributed across the full
of the vehicle (or absorbed by a safety barrier!).
- In January 1999 the New South Wales Government introduced
40km/h speed limits for motorists when passing buses picking up or
setting down school children. See ' Flashing
Lights for School Buses' for background on this issue.
- In December 1999 the NSW Government issued Road Safety 2010
has speed management as a key strategy.
- March 2000: There has be a promising development on this issue
the UK: The executive report for 'phase 2' of a speed limiter project
now available at http://www.its.leeds.ac.uk/projects/evsc/index.html
- Dr (now Prof) Carsten was in the media a few months ago over
the issue of
data being used to determine local speed limits (the media picked up
item as satellites spying on speeding cars - which is nonsense!). Phase
2 involved on road
trials of adaptive speed limiters, driver simulator work and computer
simulations of traffic flow effects. It all looks very promising. For
example they predict
a 20% reduction in road crashes and an 8% reduction in fuel consumption
'mandatory' speed limiters (ie vehicle unable to exceed the posted
- April 2000: MUARC
is also conducting a trial of speed limiters in Melbourne, using GPS
technology. MUARC has summaries of several related reports: The
- August 2000: IIHS(PDF) and NHTSA
HTML (or PDF)
issue reports (in May 2000 and Oct 1999) showing the link between
vehicle travel speeds and pedestrian injuries.
- Feb 01: French invention: A.C.S.
- speed Sensitive Accelerator Pedal.
- 1 Mar 01: Intelligent
Speed Management - German initiative (updated URL).
- 3 Oct 01: Swedish
project - 5000 vehicles in trials across Sweden.
- 13 Mar 02 : Paper on the TAC
Safer Car project now available from Road Safety 2001
- 26 Nov 02 SMH: Assume
the position -- new technology pinpoints radar, cameras and more.
First step towards Intelligent Speed Adaption. Blackspot.com.au.
- 9 Aug 03 Staysafe: Speed
and motor vehicles - inquiry by NSW parliament road safety
- submissions sought.
- 21 Oct 03 : Presentation
to Staysafe on Speed Control - 13 Oct 03 (800K pdf)
- 26 Oct 03: Prof Carsten's 2001 ESV paper Intelligent
speed adaptation: the best collision avoidance system (PDF). This
paper covers many of the issues associated with introducing this
- 19 Nov 03 ICBC: Unsafe speed and
aggressive driving campaign kick-off - has an excellent video.
- 25 Nov 03 NYT: Study
Links Higher Speed Limits to Deaths (regn) - IIHS Status Report "Faster Travel"
- 11 Dec 03 Action Imports: Carminder System
- uses GPS and mobile phone system to give vehicle location and speed
to a caller.
- 19 Mar 04 NewSci: Vibrating
pedal says 'ease off gas'.
- 22 Mar 04 Austroads:
Review of Literature and Trials of Intelligent Speed Adaptation Devices
for Light and Heavy Vehicles (PDF)
- 7 Apr 04: Presentation
on speed control and DRLs at WHO road safety day (PDF)
- 1 May 04: Roadsense
is an Australian website opposed to speed cameras - but the statistics
have been misunderstood (see conference papers below).
- 10 May 04 Auto Insider: Guidepoint
[GPS] system helps locate stolen vehicles (and more)
- 16 May 04 SAE Highway
Vehicle Event Data Recorder Symposium June 3-4, 2004, Ashburn,
- 19 Jun 04 AAP: Effects
of an active accelerator pedal on driver behaviour and traffic safety
after long-term use in urban areas (abstract) - compliance
with the speed limits improved considerably. Reduction in average
speeds and less speed variation by the test vehicles indicate a great
traffic-safety potential. Travel times were unaffected, while emission
volumes decreased significantly.
- 1 Sep 04 SMH Drive: Remote
control (more big brother nonsense)
- 3 Oct 04 New Scientist: READING
THE SIGNS Drivers may soon have to come up with a better
excuse than “Sorry
officer, I didn’t know I was speeding” thanks to a new electronic
device that can recognise passing road signs, such as speed limits, and
warn drivers not to ignore them.
- 20 Oct 04 Australian Transport Safety Bureau brochure (PDF): Impact speed
- Will you stop in time?
- 5 Nov 04 Fleet News: Study
puts brakes on speeding fleet drivers
- 3 Feb 05 BBC: Clever cars
taking to the road - Parents,
says Mr Illsley, might be interested in a vehicle that they can set the
upper speed for, especially if they have teenage sons who are eager to
get behind the wheel.
- 21 Feb 05 AAP: Would
relaxing speed limits aggravate safety?: A case study of Hong Kong
- The relaxation of the speed limit
from 70 to 80 km/h increased the Fatal+Serious accident counts by 36%.
- 7 May 05 ETSC report: The
Safety of Vulnerable Road Users
in the Southern,
Eastern and Central European Countries - recommends expediting
- 9 May 05 Fleet News: Speed
cameras fail to cut road deaths - more correctly the road toll has
not changed much (but other factors like mobile phone use confound the
- 27 Jun 05 CNN: System
reads speed limits for drivers
- 1 Jul 05 AAP (abs): Intelligent
speed adaptation: accident savings and cost–benefit analysis.
- 3 Aug 05 AAP (abs): Are
speed enforcement cameras more effective than other speed management
measures? An evaluation of the relationship between speed and accident
- 9 Dec 05 CNN: Device
stops speeders from inside car - "discovered" by North America some
8 years after Europe and Australia! Otto Driving Companion (product)
- South Australian Dept Transport: 50 km/h speed limit – The Facts.
- 23 May 06 IIHS Status Report: Bad statistics leads to misinformation
- 12 May 06 New Scientist (subs): How to kick the habit - Well, there is a quick fix. In one decisive act, the government could save in excess of 50 million gallons of gasoline..[55mph
national speed limit - which would also save 1000s of lives. Note that
every minute saved by travelling at excessive speed is matched by a one
minute reduction in life expectancy of somebody in the community due to
increased risk of a fatal accident].
- 20 May 06 NHTSA: Analysis of Speeding-Related Fatal Motor Vehicle Traffic Crashes - In
2002, 13,713 fatalities -- about a third of all fatalities that
occurred in motor vehicle traffic crashes were speeding-related, i.e.,
at least one of the drivers involved in the crash was speeding. Figure 19 gives strong reasons to top-speed limit motorcycles!
- 31 May 06 BREAKTHROUGH: Speed Alert
- PDA or mobile phone displays speed zones and alerts driver to
speeding and school zones - Sydney covered in inital release. Aug 06:
Now on sale.
- 15 Jun 06 LiveScience: New In-Car Device Warns Speeding Drivers.
- ATSB: Beliefs and Attitudes about Speeding and its Countermeasures - May 06
- 9 Aug 06 Fleet News BREAKTHROUGH: British Gas opts for speed limiters
- BRITISH Gas is demanding manufacturers fit speed limiters to its
fleet of more than 10,000 vans in a bid to ensure its drivers remain
safe on the road.
- 30 Jan 07 Question: Half of all fatal car accidents occur at or below what
- New Zealand Accident Compensation Corporation: Down with Speed.
- 28 Feb 07 ETSC (published May 2006): Intelligent Speed Assistance - Myths and Reality.
- 28 Feb 07 Thinking Highways: Adapt to Survive. (thanks John Gill)
- 21 Sep 07 FleetNews: Speed limiter plan to make roads safer.
- 7 Nov 07 Wikipedia entry on ISA.
- 9 Jan 08 Brisbane Courier Mail: Move to speed-limit fast cars
- 13 Jan 08 SMH: Big Brother speed control to be trialled - not sure where the "Big Brother" came from, or my title as "Queensland Transport Consultant"! + News.com: Secret car speed-limiter trials.
- 14 Jan 08 ACRS 07: Demonstration of Advisory Intelligent Speed Adaptation Technology in Western Australia - excellent review of current trials and developments
- Regan, M., Triggs, T., Young, K., Tomasevic, N., Mitsopoulos, E.,
Stephan, K., and Tingvall, C. (2006). On-Road Evaluation of Intelligent
Speed Adaptation, Following Distance Warning and Seatbelt Reminder
Systems: Final Results of the Australian TAC SafeCar Project. Volume 1:
Report. Monash University Accident Research Centre Report 253. MUARC: Melbourne, Australia
- 1 May 08: NSW RTA Speed Page now has a crash test video showing a recent model car crashing at 60km/h and 100km/h + 40 & 50 km/h speed limits on NSW roads
- 1 May 08 ETSC: Lower speeds: Win-Win for Road Safety and the Environment + Managing Speed: Towards Safe and Sustainable Road Transport:
- Adopt European legislation for mandatory ﬁtting of European
cars with informative or supportive Intelligent Speed Assistance
systems in the type approval procedure for cars. This Directive should
include technical requirements and an implementation timetable.
- As a ﬁrst step, promote the industry’s efforts by
supporting additional research and standardisation, by introducing tax
cuts as incentives to install ISA and becoming ﬁrst customers of ISA
technology. As a second step, require informative or supportive
Intelligent Speed Assistance systems by law. Authorities in charge of
the road network management should, possibly in co-operation with
the private sector, develop a digital database of all the speed
limits on the network and make this
database available for GPS application as a prerequisite to the implementation ISA systems.
- 13 May 08 [UK] Daily Mail: Satnav that tells you not to break the speed limit
- 2 Jun 08 Boston.com: As fuel prices rise, some speedometer needles fall.
- 3 Jun 08 ABC: Perth motorists nation's worst for speeding: survey.
- 16 Jun 08 IIHS Status Report, Vol. 43, No. 1 - Speed (PDF)
- 25 Jun 08 SMH: Big brother satellites to put brakes on speeders + NZH: High-tech backseat driver set for trials + ABC: Speed-limit device trialled in cars + LiveNews: Big Brother's under your hood: Govt trials new speed tracker + Gold Coast: Cars to trial Big Brother speed control.
[Comment: There is no "Big Brother" watching/tracking the cars - the
system uses GPS to determine the road and speed and an on-board digital
map of speed limits]. RTA: ISA webpage - with Flash video
- 1 Aug 08 CNet: Sat-navs set to nag about speed limit.
- 8 Aug 08 Transport Canada: Heavy Truck Speed Limiter Reports.
- 16 Sep 08 Uk Telegraph: Drivers could have speed limited by satellite devices
- 17 Sep 08 Express: NEW 'BIG BROTHER' CONTROL ON ALL CARS TO STOP SPEEDING
(opinion: It is a pity that organisations like RAC and AA do not do a
little homework before coming out with misinformed criticisms)
- 17 Sep 08 UK DfT: Intelligent Speed Adaptation (ISA) - project reports
- 13 Oct 08 ABC South Australia: 'Creeping' motorists targeted
- Motorists who drive several kilometres an hour over the speed limit
are being targeted in a State Government road safety campaign.
- 17 Dec 08 ACRS: Heavy vehicle speed management - policy paper
(Doc) - [ISA] technologies, either acting separately or in tandem, have
significant potential to assist operators to comply with speed limits,
meet Occupational Health and Safety obligations while potentially
reducing greenhouse gas emissions and improving business profitability.
- 18 Dec 08 Drive: Red alert on speeding - The (passive ISA)
device can be purchased now as a satellite navigation unit for $249 -
or, from February, downloaded to any GPS-enabled mobile phone or PDA
(personal digital assistant) for a monthly subscription of $9.90.
- 31 Dec 08 Financial Times: Advisers urge fast action on speed limiters
- Fitting cars with speed controllers could cut road injuries by a
quarter and reduce air pollution... + Commission for Integrated
Transport: Speed limit adherence and its effect on road safety and climate change.
- 31 Dec 08 Moldova: Nissan debuts world's first intelligent cruise control
- Utilizing route-information fed through the on-board navigation
system, the Intelligent Cruise Control system can modulate the
vehicle-speed in anticipation of the next curve on the road [but no
mention of ISA]
- 15 Jan 09 European Commission: The when, where, why of road accidents
- The greatest additional benefits – a 6-10% improvement in terms
of injuries – are expected from speed adaptation systems [note
that the estimated ESC benefits are highly dependent on local
conditions and are unlikely to be realised in Australia]
- 5 Mar 09 The Citizen (UK): Lancashire drivers to test new 'road safety sat navs
- 7 May 09 SpeedAlert: Would you like to help us Beta trial one of the most revolutionary Speed Limit Awareness software products in Australia?
- 11 May 09 Times: Speed-curbed cars launched in Government trial + Taxis and buses face automatic speed limiting + Telegraph: Speed-restricted car: a review.
- 12 May 09 BBC: Speed limit device tested on bus + Autocar: Speed limiter tests in London
- 14 May 09 Transport Briefing: TfL urges sat-nav makers to embrace ISA technology
- 19 May 09 Daily Telegraph: NSW plan for speed limiters in all cars.
- 23 Sep 09 Apple iTunes/Sygic: Intelligent Speed Assistance function now available for the Apple iPhone. Does not currently handle school zones.
- 16 Oct 09 Australian Mining: VDO launches Speed Alert to handle varying speed limits (not the same as SpeedAlert)
- Nov 09: Low Range Speeding and the Potential Benefits of Intelligent Speed Assistance
(600K PDF preprint of conference paper). 12% of casualty
crashes would be saved if those who regularly drive between
2 and 10km/h over the speed limit obeyed the speed limits. Fatality
savings would be much higher.
- 16 Dec 09 Drive: Melbourne driver stuck on cruise control - Comment: Cruise control forces the vehicle to travel at a minimum speed
unless there is driver intervention (or the system fails - in this case
the brake pedal signal to the ECU appears to have failed and so
braking did not deactivate the cruise control. To make matters worse,
by design, the ignition could not be turned off and the transmission
could not be changed!). Many fatigue-related crashes in outback
Australia involve the driver falling asleep when cruise control is
engaged. Active ISA
can replace cruise control as a way of maintaining an appropriate speed
on the open road and has significant road safety benefits.
- 14 Jan 10 The Age: GPS tool to warn speeding drivers (note that the Navig8r G35 sat-nav already has SpeedAlert. Also the greatest benefits of ISA will come from a reduction in inadvertent speeding) + Herald Sun: Hoon drivers to be used in test of government's new GPS speed device.
- 17 Apr 10 ETSC: Safety Monitor April 2010 - Speed
is the most important contributory factor to road deaths and injuries,
playing a role as a contributing factor in one third of all fatal
collisions. Speeding remains extremely widespread, it is estimated that
at any one moment about 35% of drivers exceed speed limits outside
built-up areas and as much as 50% in urban areas.
- 5 May 10 ANE: Vans, light trucks face [top] speed limiters in EU - to prevent them exceeding 120 km per hour...
- 25 Oct 10 Daily Telegraph: Calls for anti-speeding beep test by RTA. RTA research report.
- 21 Dec 11 CASR: Advisory Intelligent Speed Adaptation for government fleets - ISA was found to have the potential to reduce casualty crashes in government fleets by 20%.
- 21 Dec 11 EconPapers: An Energy and Emissions Impact Evaluation of Intelligent Speed Adaptation.
- 21 Dec 11 ATRF 2011: Analysis of a financial incentive to encourage safer driving practices.
- 21 Dec 11 PRAISE: Driving for Work and Managing Speed
- 25 Jun 12 Drive: $25 [a week] not to speed - financial reward virtually eliminates speeding in US study.
- 5 Sep 12 Mix Telematics: Managing driver speed.
- 5 Sep 12 India Today: Government plans pre-fitted GPS devices on vehicles to check speed
- 4 Dec 12 Foxbusiness: Will Insurers Soon Pay us Not to Speed? See also Pay-How-You-Drive car insurance
- 5 Dec 12 IIHS Status Report: Intelligent speed adaptation devices can reduce speeding.
- 18 Feb 13 Accident Analysis & Prevention, Volume 52 ($): Fractions of fatal crashes attributable to speeding: Evolution for the period 2001–2010 in France - future policy should focus on low and medium-level speeding in order further to reduce road deaths significantly, since these levels now correspond to the major fraction of fatal crashes.
Related Australasian Road Safety
Policing and Education Conference Proceedings (sorry but the website is not currently available
Developments in Safer Motor Vehicles
Conference organised by SAE Australasia and NSW
16-17 March 1998 Parliament House, New South Wales
WHY CONSIDER SPEED CONTROL DEVICES FOR
In the recently published NSW road accident statistics for 1996 it is
stated that 38% of all fatal accidents were speed related. In other
words, 38% of
all fatal crashes could have been avoided or made less severe if the
had been travelling at a more appropriate speed for the circumstances.
When we think of speed-related accidents we usually think of
high-speed crashes. In fact most fatal accidents occur at impact speeds
well under 70km/h.
SPEED AND CRASHES
Probability of fatality or serious injury
Figure 1 is based on casualties to seat belt wearing drivers in
car crashes in the USA between 1982 and 1991 (Evans,
The probability of serious injury or death is plotted for a range of
speeds (more correctly delta V - the change in velocity). Notice that
fatal curve rises steeply beyond 60km/h. .
Table 1 Probability of belted driver being killed or
severely injured in two car collisions
|Delta V (km/h)
||Prob. of fatality
||Prob. of sev. inj. or fatality
Figures 2 shows the frequency distribution of impact speeds for
data as the previous figure. Notice that half of all fatalities to
drivers occurred at less than 45km/h. Although the risk of a fatality
low at these speeds the total number of reported crashes (including
crashes) in this impact speed range is much greater than at the higher
speeds. This suggests that measures which address impact speeds in the
30 to 50km/h are just as important as those which address higher
Remember that these data are for seat belted drivers.
The Australian New Car Assessment Program started offset crash
testing in 1993. In 1995 the impact speed for the offset test was
raised from 60km/h to 64km/h in line with international practice. This
resulted in a noticeable difference in crash severity. A speed increase
of 6% resulted in a 13% increase
in impact energy.
While advanced features such as airbags can have a significant
influence on the many crashes that occur at or below the current NCAP
test speed it
is likely that other factors, such as structural failure will influence
outcome of crashes at higher speeds.
These pictures show some vehicles with longstanding safety
reputations at the peak of the 64km/h offset crash test.
Offset crash tests of Mercedes E-Class and Volvo 850 at 64km/h
into a deformable barrier (courtesy Insurance
Institute for Highway Safety)
These and other crash tests suggest that, at impact speeds of
around 70km/h, a vehicle reaches physical limits to its ability to
protect front seat occupants.
Screen shots from the Video "The Physics of Car Crashes" by the Roads and Traffic Authority of NSW
(Marketing Dept phone 02 92186315, fax 02 92183510). These are full
crashes into a rigid barrier.
An aim, then, of speed management measures is to reduce impact
speeds - preferably to zero (ie no impact).
Stopping distances are not often appreciated by motorists. When
travelling at 60km/h an alert motorist will typically travel 25m
between the time that
an object becomes visible (but not necessarily seen) and the
when their foot hits the brake pedal. We tend to only think of stopping
after our foot hits the pedal!
For a given set of road conditions the impact speed depends on the
initial travel speed (Paine & Fisher 1996).
Using typical driving conditions it can be shown that the probability
of a driver fatality is highly sensitive to the initial travel speed of
the vehicle. The table shows the result of this analysis where the
distance to the hazard is 50m (alert reaction time of 1.5s, heavy
braking). Again the probabilities are for seat-belted drivers. .
Table 2 Relationship between travel speed and outcome for one
The probability of fatality of serious injury is highly sensitive
travel speed - a few km/h can make a big difference in the outcome of a
|Travel Speed km/h
||Impact Speed km/h
||Prob. of fatality
||Prob. of severe inj or fatality
This analysis supports Swedish research (Nilsson
which suggests a fourth power relationship between mean traffic speed
the proportion of fatal crashes. A 3% reduction in mean traffic speeds
produce a 12% reduction in fatal crashes. On this basis measures which
mean traffic speeds by 2km/h in urban areas and 3km/h in rural areas
have saved 71 fatal crashes, 342 serious crashes and 1191 other injury
in NSW during 1994.
A similar relationship between initial travel speed and risk of
fatality exists with cars hitting pedestrians, except that, in
effect, the probability
of a fatality reaches 100% at an impact speed of 60km/h
"Vehicle Travel Speeds and the Incidence of Fatal Pedestrian Crashes"
by Anderson, McLean, Farmer, Lee and Brooks, J. Acc Anal. and Prev, Sept
COMPLIANCE WITH SPEED LIMITS
Compliance with speed limits
This section discusses possible voluntary measures.
It is speculated that "unintentional" speeding makes up a large
proportion of the speeding problem and that drivers could do with more
keeping to the speed limit. Many cars now have speed alarms or cruise
fitted but there is currently no automatic way to inform these devices
the posted speed limit. ITS technologies give us the opportunity to
roadside devices to transmit speed limit and other information to
vehicles. Trials of these "automatic speed limiters" are underway in
Swedish city of Lund (Hyden 1993) and in the
If the road infrastructure was in place then the voluntary fitting
of speed alarms and automatic cruise control could become quite
popular. The price would be similar to the now-banned radar detectors
and they would also
help drivers avoid fines and loss of licence!
Top speed limiting
Top speed limiting is a controversial issue. Again, discussion
confined to possible voluntary measures.
There has been a recent significant change in vehicle technology
which makes top-speed limiting very cheap.
Many cars these days have electronic engine management systems.
Most of these already have a top speed setting but typical settings are
in excess of 200km/h. It should be relatively simple to provide a more
- it is known that some manufacturers produce chips with different
settings for different international markets.
My point is that there is a potential market for optional
speed-limited vehicles - with the appropriate chip fitted on the
A speed-limited vehicle would have the same performance as an
unlimited vehicle up to the preset speed. However, the engine power
would drop off above
that speed. A consequence is that the driver would no longer take the
of trying to overtake at grossly excessive speeds (Plowden
& Hillman, 1984 - Plowden also discusses alternatives to an
instant drop off in power. For example TNO in the Netherlands is
currently evaluating an actuator which increases the accelerator pedal
stiffnes when a set speed is exceeded). Speed limiting would be a
strong deterrent to theft and joyriding. And there is the issue of
teenagers borrowing the family car! In the latter case this could be an
additional application for smart keys, which adjust the seating
position according to the programmed key which opened the door. The
speed limiter could be set to the Australian provisional driver speed
limit of 80km/h.
Optional speed limiting could attract significant insurance
Voluntary speed-limiting need not carry a stigma. After all,
Formula 1 racing drivers have resorted to speed limiters to avoid the
severe penalties of speeding in the pit lane.
Speed-limited in pit-lane (courtesy www.f1-photos.com)
Evans L (1993) 'Driver injury and fatality risk
crashes versus mass ratio inferred using Newtonian Mechanics', Proceedings
of 37th Conference of Association for the Advancement of Automotive
Medicine, San Antonio, Texas.
Hyden C (1993) 'The Speed Limiter- a Simple
Efficient Safety Device', Proceedings of 26th International
on Automotive Technology and Automation, Aachen, Germany.
Nilsson G (1993) 'Relationship between speed
and safety: calculation method', The Speed Review: Appendix of
Speed Workshop Papers, Federal Office of Road Safety, Report
CR127A, Department of Transport
and Communications, Canberra.
Paine M & Fisher A (1996) ' Flashing
Lights for School Buses', Proceedings of 15th International
of the Enhanced Safety of Vehicles, Melbourne.
Plowden S & Hillman M (1984) Danger
road: The Needless Scourge, Policy Studies Institute, London.
RTA (1998) Road Traffic Accidents in
NSW-1996, Statistical statements for the years 1996 & 1994.
Links to WWW sites with offset crash test data: http://www4.tpg.com.au/users/mpaine/ncaplist.html
Any views expressed in this report are those of the author and do not
reflect the views or policy of any government agency or other
organisation. It is
provided on the Internet in the interests of disseminating road safety
While the information presented is believed to be accurate no
can be given in this regard.
- 25 Oct 03: Following a ridiculous
statement about scrapping speed cameras in my local paper, the Manly
Daily, from a local member of parliament I wrote to the editor to point
out the risk of exceeding the speed limit. So far (a week later) the
editor has not published my letter. Here it is:
Humpherson really needs to do his homework before calling for the
scrapping of speed cameras (MD 18 Oct). For at start he should read the
transcripts of my evidence to the Parliamentary Staysafe Committee
earlier that week.
claim, by the British sociology
researcher, that speed cameras had not reduced the road toll is
questionable. Measuring the effectiveness of road safety measures from
the overall road toll is notoriously difficult due to the many
influencing factors. The best way is to conduct in-depth crash
investigations. Across several continents over many years those
in-depth studies show that about half of all road fatalities occur an
impact speed of just 55km/h or less. The faster a motorist is
travelling the less chance they have of avoiding a crash and the higher
the impact speed if they do crash. This double whammy effect means that
travelling at just 5km/h over the speed limit doubles the risk of being
involved in a serious or fatal crash (this was demonstated by road
safety researchers at the University of Adelaide in a landmark study
several years ago).
Other studies in the USA have shown
that, in effect, every minute saved by travelling in excess of the
speed limit results in a one minute loss in life expectancy across the
community due to the increased risk of a fatal crash. The community
clearly benefits from anti-speeding measures such as speed cameras.
My main message to the Staysafe
Committee was that motorists have a false sense of safety at "normal"
suburban speeds and there is the temptation to travel faster than the
speed limit. Speeds that seem safe can suddenly turn out to be
dangerous - ask just about anyone who has been involved in a serious
crash. That is why I have suggested that motorists could do with
assistance in keeping to the speed limit through smart technology in
the car. Several trials of "Intelligent Speed Adaptation" in Europe and
Australia are exceeding expectations in effectiveness, driver
acceptance and environmental improvement. The systems that impress me
most give the driver a simple, subtle (silent) indication that the
speed limit is being exceeded such as vibrating the accelerator pedal.
In a few years I expect that such systems will be a selling feature of
GPS navigation units in cars.
Automotive Safety Consultant
Manly Daily often prints negative opinions about speed cameras but I
rarely see any attempt to verify the questionable claims that they do
not reduce the road toll. This is nonsense, as several lines of
research have shown.
Early in April I gave a presentation
on speed control at the World Health Organisation Road Safety Day
in Sydney (see link below for a copy of my presentation). Two key
points that motorists should be aware of are:
1. Half of all fatal accidents occur
at an impact speed of less than 55km/h. "Low speed" collisions can be
deadly. This is due to Newton's physics and the frailty of the human
2. Every 5km/h above the speed limit
doubles the risk of being involved in a casualty accident. In a 60
zone, travelling at 65km/h doubles the risk and travelling at 70km/h
quadruples the risk.
For several years I have been calling
for measures that assist motorists comply with speed limits (and,
incidentaly, avoid speeding tickets). GPS navigation technology is
bringing that closer to reality.
- 8 May 04
his sarcasm Mr Ditmarsch has hit the nail on the head with his comments
on my letter about speed camera. Careful research in South Australia
has shown that travelling at 80km/h in a 60 zone increases the chances
of being involved in a casualty crash by 32 times, compared with risk
when travelling at 60km/h. This is illustrated in the attached graph,
which is based on that research. Independent research in Sweden, the
United Kingdom and the USA has come to the same conclusion.
Speed limits are normally set
according to the road and traffic conditions, including the risk to
vulnerable road users such as pedestrians (see www.austroads.com.au). Under these circumstances, the risk of
being involved in a casualty crash while travelling at 110km/h on a
freeway is roughly the same as the risk when travelling at 60km/h on a
suburban road with a 60 speed limit. It is when the speed of the
vehicle exceeds the posted speed limit that the risk climbs
40km/h speed zones usually apply
where there is an increased risk of hitting a pedestrian. At an impact
speed of 60km/h there is almost a 100% chance that a pedestrian impact
will be fatal. Also in half of all pedestrian fatalities the motorist
has no chance to brake before the impact. So I agree with Mr
Ditmarsch's calculation that travelling at 60km/h in a 40 zone
would increase the risk of a casualty crash by 32 times. In this
case the most likely casualty is a pedestrian - not himself. The
problem is that, in modern cars, 60km/h in these circumstances feels
safe - but that is an illusion.
SMH 8 MARCH 2010
Safe speeding reduces road toll ... in your dreams
The Mercedes-Benz safety expert Ulrich Mellinghoff is living in a dream
world where everyone drives on speed-limitless German autobahns in a
luxury car equipped with the latest safety features ("Fast drivers and
a falling road toll: Germans show how", March 5).
Most Australians drive cars with poor or mediocre crash safety, and
most fatalities occur on urban roads or two-lane country roads. More
than half involve crash impact speeds less than 60km/h (even in a
Numerous peer-reviewed studies have shown that the fatal crash rate is
very sensitive to the speed of vehicles. Exceeding the speed limit by
just a few kilometres an hour greatly increases the risk of a fatal
crash. The recent national change to 50km/h speed limits on residential
streets has resulted in a halving of fatalities on these streets in
Doing 70km/h in a 60km/h zone may feel safe in the modern car, but that
is an illusion. If an emergency arises, that extra speed more than
doubles the risk of a serious or fatal crash.
Recent developments with GPS technology mean it is now much easier to
drive within the speed limit at all times ˆ not just near speed
cameras. An Australia-wide speed limit advisory function is available
on some satellite navigation units that cost less than a speeding fine.
As a vehicle safety consultant I have been evaluating these devices
since 1996 but they have been mostly ignored by the motoring media, who
seem to be immersed in the same virtual world as Mr Mellinghoff.
Michael Paine Beacon Hill