Glossary

Definitions used in these crash publications.

Casualty: person who sustained fatal, serious or minor injuries.

Crash, casualty, vehicles involved: These terms often cause some confusion. A single crash may involve multiple casualties and multiple vehicles.The following example may help to clarify their use. If two motor vehicles collide, one motor vehicle crash has taken place. If four people in one of the vehicles were injured and two in the other, then this one crash resulted in six casualties. The number of vehicles involved was two.

Crash fault/responsibility: The behaviour of several drivers may contribute to a crash, but only one driver is assigned the primary responsibility. This driver is called the at-fault driver. Primary responsibility (at-fault) for a crash is based on the crash movements and crash cause factors assigned in the Crash Analysis System. It is not based on legal liability or court conviction. Fault/responsibility here only considers driver and rider factors contributing to the crash. There may also be road or system factors that contributed to the crash.

Cyclist crashes: The data in these pages for years before 2014 include only crashes that involve a motor vehicle. A crash between a cyclist and a pedestrian, for example, would not be included. The data from 2014 includes on-road cyclist crashes even when a motor vehicle is not involved in the crash. Very few such crashes are reported to the police and recorded in the Crash Analysis System.

Exclusions: There are a number of cases where road deaths or motor vehicle deaths are not included in the official road toll. They include:

  • Deaths that do not occur on a public road or a road to which the public has access (eg race track or farm paddock).
  • Deaths that did not result from injuries sustained in the crash ( eg. when the coroner determines that a driver died from a heart attack).
  • Suicide or murder.
  • Deaths on the road where a motor vehicle was not involved (eg cyclist only crash).
  • These definitions are in line with the most common international definitions. Although these deaths are excluded from the official road toll a record is kept of the crash details.

Factors contributing to crashes: these are the factors identified as contributing to crashes (i.e. causes of crashes). On each crash report there may be several factors coded against each vehicle involved in the crash for driver or vehicle faults. In addition there may be a number of factors coded on each report for faults of other road users, weather or other conditions.

Alcohol/drugs as a contributing factor: For 2016, alcohol information from crash reports is not comparable with earlier years. Prior to 2016, alcohol/drugs is listed as a factor when a driver’s blood or breath alcohol level is above the legal limit, if drugs are proved to be in the driver’s blood, or when the attending officer suspects that alcohol/drug consumption contributed to the crash. From 2016 officer suspicion is not included. The reason for this change is a change in the crash reporting process as explained in the following note from the NZTA’s Crash Analysis System.

Notes from NZTA's Crash Analysis System (CAS) -13 September 2017

Over the last few years the NZ Transport Agency, NZ Police and the Ministry of Transport have been working to improve how road crash information is recorded, processed and then provided to the road safety community. As you may know there have already been some changes. The NZ Police now submit crash information electronically via iPhones and we are maximising this data by improving and modernising CAS through the CAS replacement project.

Alcohol suspected (July 2017): Previously we let you know that, since July 2016, we have noticed a sharp increase in alcohol related crashes recorded in CAS. Alcohol related crashes include crashes where alcohol is suspected but we do not have a breath/blood alcohol result (factor 101), and where an alcohol test has shown the driver to be over the limit or where a test was refused (factor 103). We noted that the increase was being driven by a sharp increase in factor 101 ‘alcohol suspected’. NZTA and NZ Police have been investigating what is driving this trend and are now able to advise that this is due to:• Understanding how business rules around alcohol suspected cases are applied and interpreted between NZTA and NZ Police• Since NZ Police moved to electronic data collection, Traffic Crash Reports are received by NZTA quicker and fewer crashes with alcohol suspected have subsequently been updated with a blood or breath alcohol result. These crashes remain 101 ‘alcohol suspected’ as opposed to being recoded as a 102 -‘alcohol test below limit’ or 103 –‘alcohol test above limit or test refused’. NZTA and NZ Police are working together to implement a common understanding of alcohol suspected, and to ensure alcohol crashes are updated, and are taking steps to bring this data up to date with the receipt of more alcohol test results. As we receive these some 101 codes will change to 103 and some to 102 (alcohol test below limit). Because of this, care should also be taken when analysing codes 102 and 103.In the meantime, we would suggest that you exclude 101’s from your analysis if it is possible for you to do so.

‘Failed to adapt to New Zealand driving conditions’: This factor is used when the fact that an overseas driver failed to adapt to New Zealand driving conditions contributed to the crash. This includes drivers who were not used to our driving conditions or who didn’t understand or remember NZ road rules – for example, drivers from countries that drive on the right, driving on the wrong side of the road, or not understanding give way rules.

'Travelling too fast for conditions': This factor is not limited to travelling above the posted speed limit, but also includes travelling too fast for the traffic, road or weather conditions.  

Fatal injuries: injuries that result in death within 30 days of the crash. Up to and including 1974 it comprised injuries that resulted in death within 28 days of the crash.

Holiday periods

The Christmas - New Year holiday period is that which begins in December of the year stated.

The length of the official holiday period varies depending on where the statutory holidays fall in relation to the weekend.

When Christmas Eve and New Year's Eve fall on a week day the holiday starts at 4.00 pm on 24 December.

If the holiday begins on a Monday or a Tuesday then it ends at 6.00 am on 3 January (9.6 days).

If the holiday begins from Wednesday to Friday then it ends at 6.00 am on 5 January (11.6 days).

When Christmas Eve and New Year's Eve fall on a Saturday the holiday starts at 4.00 pm on Friday 23 December and ends at 6.00 am on Wednesday 4 January (11.6 days).

When Christmas Eve and New Year's Eve fall on a Sunday the holiday starts at 4.00 pm on Friday 22 December and ends at 6.00 am on Wednesday 3 January (11.6 days).

The Easter holiday covers the period from 4.00 pm on the Thursday to 6.00 am on the Tuesday.

Queen's Birthday and Labour Weekends cover the periods from 4.00 pm on the Friday to 6.00 am on the Tuesday.

Minor injuries: injuries of a minor nature such as sprains and bruises.

Motor vehicle crash: any crash that occurs on a public road that is attributable directly or indirectly to a motor vehicle or its load. Crashes which do not occur on public roads are excluded e.g. tractor crashes on farms are not included. The data in this statistical statement includes only crashes that involve a motor vehicle. A crash between a cyclist and a pedestrian, for example, would not be included.

Motorcycle / moped: On these pages all mopeds and motorcycles have been included under the one heading of "Motorcycles". For the purposes of registration and licensing a moped has a power output of 2kw or under and a maximum design speed of 50km/h or under.

Movement classification of crashes: This is based on the manner in which the vehicles were moving immediately prior to the crash. Bicycles are treated as vehicles for this purpose. These movements are divided firstly into broad classes.

Non-injury crashes: Statistics concerning crashes involving property damage only are not included in this report.

Open Road and Urban areas: where the terms "Urban" and "Open Road" are used:

Urban refers to all speed limit areas of 70 km/h and under and limited speed zones.

Open Road refers to all speed limit areas of over 70 km/h.   

Overseas driver: a driver in a crash who was driving on an overseas licence.

Serious injuries: fractures, concussions, internal injuries, crushings, severe cuts and lacerations, severe general shock necessitating medical treatment and any other injury involving removal to and detention in hospital.

Trucks: includes light trucks.

Vulnerable road users: road users not inside motor vehicles such as pedestrians, cyclists and motorcyclists.

Young drivers: for the purposes of this material, young drivers have been classed as those aged between 15 and 24 years old for consistancy of time series. Please note that the minimum age for holding a learner driver licence increased from 15 to 16 years old in 2011.

References

The facts about crashes reference various publications and research. More infomation about them is available below.

Alcohol:

Evans, L. (2004) Traffic Safety, p141.

Keall, M. D., Frith, W. J & Patterson, T. L. (2004) The influence of alcohol, age and the number of passengers on the night-time risk of driver injury in New Zealand. Accident Analysis and Prevention, 36(1), 49–61.

Speed:

Archer, J., Fotheringham, N., Symmons , M. and Corben B. (2008) The Impact of Lowered Speed Limits in Urban and Metropolitan Areas Monash University Accident Research Centre report 276.

Patterson, T.L., Frith, W.J., and Small, M.W. (2000) Down with Speed: A review of the literature, and the impact of speed on New Zealanders Accident Compensation Corporation and Land Transport Safety Authority. Wellington. www.transport.govt.nz/research/Documents/ACC672-Down-with-speed.pdf(external link)

Diverted attention:

Gordon, C., (2009) Reviewing how distraction involvement is coded in the New Zealand crash analysis system, in Road safety data: collection and analysis for target setting and monitoring performances and progress. IRTAD, Seoul. p 73

Regan, M. A., Lee, J. D. & Young, K. L. (eds.) (2008) Driver distraction: Theory, effects and mitigation. Florida, USA: CRC Press.

OECD (2006) Young drivers: The road to safety. p 82