Fact sheet

Serious road injuries in the Netherlands

Summary

This fact sheet discusses the development of the number of serious road injuries (SRI) in the Netherlands during the period 1993-2015. After an initial decrease from the 1990s onward, the number of serious road injuries has been increasing since 2006. In 2015, an estimated 21,300 people were seriously injured in traffic in the Netherlands. As such, the number of serious road injuries has now reached the highest level since 1993, the first year in which the number of serious road injuries was assessed.

Cyclists constitute almost two thirds of the number of serious road injuries, a majority of which are injured in non-motor vehicle crashes. In proportion to the total population, many serious road injuries occur among youths (15-19 year-olds) and among road users aged 45 and older.

The data is based on a combination of the police crash report database (BRON) [i] and hospital data (LMR/LBZ) [ii]. Particularly crashes in which no motor vehicle is involved have a very low report rate in BRON. After 2009, it has been difficult to monitor the developments of all crash types, also those involving a motor vehicle, because since that year the BRON crash report rate has been subject to a strong decline. In later years only data of hospital admissions is available. In 2014 and 2015, the registration rate in BRON of serious road injuries improved, but important characteristics are not always registered; for example transport mode (of casualty and of crash opponent), name of the hospital, speed ­limit of the road on which the crash occurred, and whether this was an urban or a rural road.


[1] BRON: Registered Crashes in the Netherlands, crash registration under the responsibility of the Ministry of Infrastructure and the Environment (IenM). BRON contains mainly data registered by the police.

[ii] LBZ: National Basis Register Hospital Care; until 1 January 2014 this was the National Medical Register (LMR). This file is maintained by Dutch Hospital Data (DHD).

Facts

When is a casualty a serious road injury?

A serious road injury is a road crash casualty who has been admitted to hospital and has not died within 30 days after the crash. The injury severity of the casualty must be 2 or higher, expressed in the Maximum Abbreviated Injury Score (MAIS) [1]. MAIS is an international standard to indicate the severity of an injury. This score can be derived from the various injuries coded for a patient. Examples of MAIS2-injuries are bone fractures and concussion with loss of consciousness.

In 2009, SWOV proposed to use this new definition for seriously injured traffic casualties. In 2010, this new definition was adopted in the Netherlands, thereby abandoning the previously used term ‘in-patients’ [2]. The new definition was adopted because not all police-reported in-patients (as were registered in BRON) were indeed severely injured or even actually admitted to hospital.

How is the number of serious road injuries determined?

SWOV annually assesses the number of road casualties based on two sources

  • the Database of Reported Crashes in the Netherlands (BRON)
    In BRON the Ministry of Infrastructure and the Environment collects and publishes the police data with respect to road crashes. BRON contains information about characteristics of the crash such as road features, vehicle characteristics and the circumstances of the crash. BRON does not contain reliable information about injury severity: many injured casualties are not included and in recent years important information is missing, like transport mode of casualty and of crash opponent, speed limit of the road on which the crash occurred, whether it was an urban or a rural road, and the name of the hospital to which the casualty has been admitted.
  • the National Basis Registration Hospital Care (LBZ)
    The national medical registration LBZ (before 1 January 2014 National Medical Register LMR) is a database managed by Dutch Hospital Data (DHD). This database contains information about the nature of the injury including body part and injury type. The register is fairly complete, although not all serious road injuries are registered as traffic casualties. Nor does LBZ contain much information about the circumstances of the crash.

SWOV estimates the number of serious road injuries in the Netherlands by linking and analysing the data in both data sources [2] [3] [4] . The quality of both  data sources is of the utmost importance for a reliable estimate of the number of serious road injuries. BRON as well as the LBZ must contain a sufficiently large number of casualties. Since the year 2010, the quality of the registers is insufficient to allow making observations concerning the developments of numbers  of serious road injuries stratified into subcategories such as age group or type of road user. However, based on the hospital registration it is possible to give an indication of the distribution by these characteristics, e.g. the proportions of male or female casualties, travel modes, or age groups .

How has the number of serious road injuries in the Netherlands been developing since 2000?

Figure 1 shows the development of the number of serious road injuries in the period 2000 to 2015. Although a decline seemed to have started in 2012 and 2013, the entire period shows a rising trend. The decline did not continue in 2014 and 2015, on the contrary: in 2015 the number of serious road injuries reached a peak since the registration began in 1993 [5].

Figure 1. Estimated number of serious road injuries in the Netherlands since 2000. Total numbers and distribution between crashes involving (M) or not involving (N) a motor vehicle. After 2009, the precise distribution between N-casualties and M-casualties cannot be determined. Sources: DHD, IenM, and SWOV.

 

The development of the number of serious road injuries is a combination of two separate trends: the trend in the number of serious road injuries in motor vehicle crashes (M-crashes) and the trend in the number of serious road injuries in crashes not involving motorized vehicles (N-crashes). Since 2006,  we can observe a stronger rising trend in the number of serious road injuries in crashes not involving motorized vehicles, while the number of serious road injuries in motor vehicle crashes – after an initial decline before 2006 – seems to flatten out. In 2014 and 2015 more than half the serious road injuries were estimated to be casualties in crashes not involving a motor vehicle.

How has the number of serious road injuries been developing for different modes of transport?

In the hospital register, cyclists (especially in crashes without a motor vehicle) constitute the largest group among the serious road injuries: more than half of the total in 2009 and a rising proportion in the following years (see Figure 2). For the sake of comparison: about one third of the road fatalities are cyclists and presently the number of fatalities among cyclists roughly equals that among car-occupants (see SWOV Fact sheet Road deaths in the Netherlands. During the last ten years, the largest increase in the proportion of serious road injuries occurred in bicycle crashes not involving a motor vehicle.

The number of serious road injuries among occupants of passenger cars and vans is the only group that has shown a significant decline over the last ten years. In 2009, this group still constituted about 15% of the number of serious road injuries in the hospital register LBZ (13.6% in BRON). Presently, less than 10% of the serious road injuries are occupants of passenger cars or delivery vehicles.

Figure 2. Number of serious road injuries in the Netherlands since 2000, distributed by mode of transport, based on the LBZ register. The precise disaggregation is unknown as the modes of transport are not always accurately registered in the LBZ. Sources: DHD and SWOV.

 

Since the year 2010 the poor registration in BRON makes it impossible to determine the number of serious road injuries per mode of transport (see How is the number of serious road injuries determined?). The distribution based on the LBZ is indicative, since the mode of transport that is registered by the hospital is not always similar to the mode of transport that is registered by the police. As the mode of transport has been missing in BRON in more than 40% of the cases since 2014, correction of LBZ data regarding transport mode using BRON data is often impossible. The development of serious road injuries by mode of transport based on the data in Figure 2 doesn't seem to differ very much from the development as indicated by the BRON data before 2010 (not in figure).

How has the number of serious road injuries been developing for different age groups?

The distribution of the number of serious road injuries among various age groups does not correspond with the composition of the population in the Netherlands, see Figure 3. This figure shows the distribution among age groups for the periods 2005-2009 (left) and 2010-2014 (right) based on the hospital registration.

Figure 3. Distribution of the population by age category (green), compared with the distribution of the numbers of serious road injuries in crashes with and without motor vehicle. The period 2005-2009 is shown on the left, the period 2010-2014 is shown on the right. The distribution of SRI is based on the hospital register LBZ which has an accurate age registration; the involvement of a motor vehicle is less certain. Sources: DHD, SWOV (serious road injuries and; Statistics Netherlands (population).

 

In both periods just over 10% of the serious road injuries were children in the ages of 0-14 whereas they constitute circa 20% of the total population. Most of the children are injured in crashes not involving a motor vehicle: either while they are cycling or on foot.

Seniors also mainly sustain injury in crashes not involving a motor vehicle, but considering their share in the total population they are overrepresented. One third of the total population are older than 45, but 57% of the serious road injuries occur in his group. This overrepresentation is probably related to their greater physical vulnerability; see also SWOV Fact sheet The Elderly in Traffic.

Crashes involving a motor vehicle are more important among the other age groups. In fact, between 2005 and 2009, the proportion of 15-19 year old serious road injuries was even more than twice the proportion of the same group in the total population. It must be noted that this has now declined. Often the casualties are 16-17 year old moped riders and 18-19 year old car drivers. The large number of serious road injuries among this group is due to the higher crash rate during the early phases of motorized traffic participation, see also SWOV Fact sheets 18 to 24-year-olds: young drivers and Moped and light-moped riders.

A development that can be observed is a shift from the group of 25-49 year old serious road injuries to the group of elderly road users (comparing the period 2010-2014 with the period 2005-2009). The elderly are an increasing share of the road casualties, among other things due to the demographic development. In addition, the proportion of over-45s among the serious road injuries is also growing stronger than their share in the population. The proportion of casualties in crashes without motor vehicles is increasing in this age group. The distinction between crashes with and without motor vehicle is somewhat uncertain in the LZB. The ages presented, however, are reliable.

What is the male-female proportion among serious road injuries?

Approximately 60% of the serious road injuries are male, and hence 40% are female. This proportion has hardly changed in recent years. However, there is a clear difference in male-female proportion for different age groups and for crashes with or without a motor vehicle (M-crashes and N-crashes), see Figure 4.

Figure 4. Proportions of serious road injuries by gender and age, for both M-crashes and N-crashes. The distribution of the serious road injuries is based on the hospital register LBZ 2010-2014. Sources: DHD, SWOV.

 

Overall, men are injured more frequently than women in motor vehicle crashes (dark blue vs dark orange bars in Figure 4). Men are also more frequently injured in crashes involving a motor vehicle than in crashes nót involving a motor vehicle (age group 15 to 54 years old; dark blue vs light blue bars in Figure 4). To some extent this is caused by differences in mobility between men and women. Whereas the proportions of male and female serious road injuries are almost equal among pedestrians and cyclists, the proportion of males among (light-) moped riders is about 75%. Among motorcyclists, about 90% of the serious road injuries are male.

If we look at the crashes without motor vehicle (N-crashes), men are overrepresented in the serious road injuries up to 60 years old. Among casualties between 60 and 85 years old in N-crashes on the other hand, the proportion of women is higher (light blue vs light orange bars in Figure 4).

The age group of 0-14 years old is responsible for about 60% of the serious road injuries in N-crashes. Above 15 years old, on the other hand, the share of motor vehicle crashes suddenly is significantly larger. At the same time we also see many male casualties in that age group. With increasing age, the share of M-crashes goes down again to reach about 40% for the over-60s. About 60% of the serious road injuries from that age onward occur in crashes without motor vehicle. Especially in this over-60s group we see more female casualties.

How is the distribution of the number of serious road injuries according to the speed limit of the road?

In addition to casualty characteristics, crash location characteristics are also important for road safety research and policymaking in this field. No data is available about crash location or crash type with respect to serious road injuries in crashes not involving motor vehicles; this data is derived from LBZ, which does not register these characteristics.

About 60% of the serious road injuries in crashes involving a motor vehicle occur in urban areas. About one-fifth of the serious road injuries in rural areas (circa 40%), occur on motorways with a speed limit of 100 km/h or higher [1].

Which types of injury do serious road injuries sustain and what is the injury severity?

Figure 5 [6] illustrates which body parts sustain serious injury and to what extent the consequences are acute or permanent. Noticeable are the large proportions of head injuries, followed by hip and leg trauma. Lasting effects are mainly the consequence of head injuries, but also of injuries to the lower leg. Casualties who suffer lasting damage mainly experience problems with their daily activities and pain. More than 20% of the casualties suffer permanent damage. The injuries and burden of injury vary between modes of transport, between different age groups and also between men and women. [6]

Figure 5. Distribution of injury and burden of injury and distribution of acute and lasting burden of injury per body part. Distributions are based on all serious road injuries in the LBZ 2000-2009 [6].
 

Serious road injuries have an injury severity with a minimum MAIS score of 2. About 70% of serious road injuries have an injury severity with a MAIS score of 2 and about 10% have an injury severity with a MAIS-score of 4 or higher. This distribution has remained fairly constant over the years. As an example the distribution for the year 2014 is presented in Figure 6 (left).

The right panel of Figure 6 shows the development over time of the numbers of LBZ-registered road casualties with MAIS 2 injury and those with more serious injury (MAIS 3+). The injury severity was found to vary between different age groups (not indicated). Among the serious road injuries older than 70, the proportion of MAIS 2 injury severity is about 44%, whereas among children aged 0-14 more than 78% of the serious road injuries have a MAIS score of 2 (LBZ, 2014; DHD).

Figure 6. Proportions of serious road injuries by injury severity in 2014 (left) and development over time of nummbers of serious road injuries with MAIS 2 injury and MAIS 3+ injury (right). The distribution in relation with severity is uncertain. Sources: DHD, IenM, SWOV.
Publications and sources

1. Reurings, M.C.B. & Bos, N.M.  (2011). Ernstig verkeersgewonden in de periode 1993-2009; Update van de cijfers. R-2011-5. SWOV, Leidschendam.

2. Reurings, M.C.B & Bos, N.M. (2009). Ernstig gewonde verkeersslachtoffers in Nederland in 1993-2008; Het werkelijke aantal in ziekenhuizen opgenomen verkeersslachtoffers met een MAIS van ten minste 2. R-2009-12. SWOV, Leidschendam.

3. Reurings, M.C.B. (2010). Ernstig verkeersgewonden in Nederland in 1993-2008: in het ziekenhuis opgenomen verkeersslachtoffers met een MAIS-score van ten minste 2. Beschrijving en verantwoording van de schattingsmethode. R-2010-15. SWOV, Leidschendam.

4. Bos, N.M., Houwing, S. & Stipdonk, H.L. (2015). Ernstig verkeersgewonden 2014; Schatting van het aantal ernstig verkeersgewonden in 2014. R-2015-18. SWOV, Den Haag.

5. Duivenvoorden, C.W.A.E., Goldenbeld, Ch., Weijermars, W.A.M., Bijleveld, F.D., et al. (2015). Monitor Beleidsimpuls Verkeersveiligheid 2015. R-2015-20A. SWOV, Den Haag.

6. Weijermars, W.A.M., Bos, N.M. & Stipdonk, H.L. (2014). Lasten van verkeersletsels ontleed; Basis voor een nieuwe benadering van verkeersveiligheid. R-2014-25. SWOV, Den Haag.

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Updated

12 Dec 2016