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ITARDA INFORMATION
交通事故分析レポート

No.104lSpecia Injuries to Older Passengers in Traﬃc Accidents
feature~How can we reduce the risk of fatalities and serious injuries? ~60.0%

65 or older
Ages 18-64

52.0
50.0%

40.0%

30.6
30.0%

22.3

20.0%

24.4

21.1
15.6

14.7
11.2

10.0%

27.7 25.2

6.2

10.0

12.7

13.8

3.4
1.0

0.0%

Head
and
Face

Neck

Chest

Abdomen

Hip

Arms

Legs Others

Rate of Fatal and Serious Injuries in 4-wheeled Vehicle Passengers
by Body parts Mainly Injured

1 Introduction・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・P2
2 Injuries to older passengers・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・P2
3 Effect of seat belt use on older passengers・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・P3
4 In which situations older passengers sustain fatal and serious injuries? ・・・・・・・・・P3
5 Characteristics deduced from Case Examples・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・P7
6 Conclusion・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・P8

lSpeciafeatureInjuries to Older Passengers in Traffic Accidents~How can we reduce the risk of fatalities and serious injuries? ~1 Introduction
Elderly population of Japan is increasing by the year and so are older drivers and older passengers. So far, manyof our reports were centered on injuries in older drivers of 4-wheeled vehicles; however in this issue we shall focus
on older passengers and analyze the situations that cause them serious injuries or fatalities while they areoccupying 4-wheeled vehicles followed by ways to reduce such risks.

2 Injuries to older passengers

Front passenger seat, 65 or older
Rear seat, 65 or older
Front passenger seat, ages 18-64
Rear seat, ages 18-64

120
100
80
60
40
20
0

2002 ʻ03

ʻ04

ʻ05

ʻ06

ʻ07

ʻ08

ʻ09

ʻ10

ʻ11

ʻ12
Year

Fig.1 Trend in casualties of 4-wheeled vehicle
passengers (per 0.1 million population)

Fatally and seriously injured(per 0.1 million population)

Casualties(per 0.1 million population)

Fig.1 and Fig.2 show respectively the trend in casualties and fatal and serious injuries caused to the front and rearseat passengers of 4-wheeled vehicles (limited to passenger cars, light passenger cars and light trucks) based on
our Traffic Accident Research Database from 2002 through 2012. Passengers aged 65 and older (hereafter “older
passengers”) account for more fatal and serious injuries and less casualties as compared to those aged 18-64(hereafter “younger passengers”) indicating that older people are more likely to die or sustain severe injuries when
met with accidents. The comparison is based on casualties per 0.1 million population.
Front passenger seat, 65 or older
Rear seat, 65 or older
Front passenger seat, ages 18-64
Rear seat, ages 18-64

5.0
4.0
3.0
2.0
1.0
0

2002 ʻ03

ʻ04

ʻ05

ʻ06

ʻ07

ʻ08

ʻ09

ʻ10

ʻ11

ʻ12
Year

Fig.2 Trend in fatally and seriously injured passengers
of 4-wheeled vehicles (per 0.1 million population)(Population is based on the ‘Population Estimates’ taken by the Statistics Bureau of Ministry of External Affairs and Communications as of October 1 each year)<The figures used hereafter are cumulative figures based on our Traffic Accident Research Database from2008 through 2012. >The composition ratio of injured occupants of driver seat, front passenger seat and rear seat reveals that older
passengers (approx. 35%) account for more casualties (Fig.3) as well as fatal and serious injuries (Fig.4) ascompared to the younger passengers (approx. 20%). While older driving license-holders are on the rise by theyear, however when seen by the license ownership ratio in 2012 it was lower (46%) as compared to younger
passengers (88%) which may be the reason for higher rate of older passenger casualties.

65 or older

20.2

65.7

14.1

65 or older

21.5

62.3

Passengers

0.0

20.0

40.0

Passengers

13.4 6.7

79.9

Ages 18-64

60.0

80.0

100.0

Composition ratio (%)
Driver seat

Front passenger seat

0.0

13.9 8.7

77.4

Ages 18-64

20.0

40.0

60.0

80.0

100.0

Composition ratio (%)
Rear seatFig.3 Composition ratio of casualties
by seat position
ITARDA INFORMATION no.104

16.2

Driver seat

Front passenger seat

Rear seatFig.4 Composition ratio of fatally andseriously injured occupants by seat position

ITARDA INFORMATION no.104

3 Effect of seat belt use on older passengers
30.0
26.9

Rate of Fatal andSerious Injuries (%)

How effective are seat belts in the event of an
accident? Fig. 5 indicates that irrespective of age orseat position, there is a significant reduction in therate of fatal and serious injuries with the use of seatbelts. However, it is also evident that the rate is 3.5
to 4 times higher in older passengers than theyounger passengers even though they were
wearing seat belts. Therefore, in the following
pages we have analyzed the situations that led tofatal and serious injuries in older passengers inspite of them wearing seat belts as well as thereason for higher rate of fatal and serious injuries ascompared to younger passengers.

Seat belt non-use
Seat belt use

25.0
20.0
15.0

12.1

11.4
10.0

7.2

5.5

5.0

4.5

2.0

1.5

0
65 or older

Ages 18-64

65 or older

Front passenger seat

Ages 18-64

Rear seatFig.5 Rate of fatal and serious injuries by age,seat position and use/non-use of seat belts(Rate of fatal and serious injuries= No. of fatal and serious injuries/ No. of casualties x 100)

4 In which situations older passengers sustain fatal andserious injuries?
(Limited to seat belt use)
■Collision of which part of vehicle leads to more fatal and serious injuries?
Frontal collision of vehicles (total of head-on, front right and front left collisions) resulted in higher fatal and serious
injuries of older passengers with front passenger seat and rear seat accounting for 76% and 68% of total collisions
respectively (Table 1). Fig.6 and Fig.7 supplement that the rate of older passengers sustaining fatal and serious
injuries regardless of whether occupying front passenger seat or rear seat is 3-4 times more than that of younger
passengers in the event of frontal collision.

Table 1. No. of fatally and seriously injured older passengers
by vehicle part collided (Total of 2008-2012)
Head onFront right

Front left

Right lateral

Left lateral

Rear total

Others

Total

Front passenger seat

1787

587

665

211

425

305

21

4001

Rear seat

490

201

164

99

133

121

46

1254

20.0
65 or older

Ages 18-64

15.0
10.0
5.0
0

Head
on

Front
right

Front
left

Right
lateralLeftlateral

Rear
total

Fig.6 Rate of fatal and serious injuries tofront seat passengers by vehicle part collided

Rate of fatal andserious injuries (%)

Rate of fatal andserious injuries (%)

Accidents with frontal collision of vehicle (Front seat: 76% of total, Rear seat; 68% of total)

20.0
65 or older

Ages 18-64

15.0
10.0
5.0
0

Head
on

Front
right

Front
left

Right
lateralLeftlateral

Rear
total

Fig.7 Rate of fatal and serious injuries torear seat passengers by vehicle part collided

ITARDA INFORMATION no.104

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regardless of their age.

60.0
50.0
40.0

65 or older

Rate of fatal and
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Rate of fatal and
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30.0
20.0
10.0
0

Head
and
Face

Neck

Chest

Abdomen

Hip

Arms

Legs

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front seat passengers by body part mainly injured

60.0
50.0
40.0

65 or older
Ages 18-64

30.0
20.0
10.0
0

Head
and
Face

Neck

Chest

Abdomen

Hip

Arms

Legs

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rear seat passengers by body part mainly injured■At what collision speed are fatal and serious injuries caused more frequently?
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seat
Rear seat

ITARDA INFORMATION no.10471
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237
64

361
99

497
147

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144

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210

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80.0

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100.0

Rate of fatal and
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60.0
40.0
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20.0
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20.0

100.0

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0

40.0

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60.0

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60.0
40.0
20.0
0

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interiors

Door andZLQGRZJODVV'DVKERDUG
vicinity

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Total

Front passenger seat

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Rear seat

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ITARDA INFORMATION no.104

lSpeciafeatureInjuries to Older Passengers in Traffic Accidents~How can we reduce the risk of fatalities and serious injuries? ~Front passenger seat; 65 or older
Front passenger seat; Ages 18-64
Rear seat; 65 or older
Rear seat; Ages 18-64

80.0
60.0
40.0
20.0
0

Seat

Other vehicle
Door andinteriors
window glass

Dashboard
vicinity

Rate of fatal andserious injuries (%)

Rate of fatal andserious injuries (%)

Fig.14 through Fig.17 show the relation of the injuring vehicle parts and the rate of fatal and serious injuries by body partsof older passengers mainly injured. Whereas the rate is low for chest injuries irrespective of the injuring vehicle part, it ishigh in case of abdomen injuries. As compared to younger passengers, seats have caused higher rate of abdomen
injuries to older passengers. Further, contact with dashboard vicinity is the reason for high rate of arm and leg injuries infront seat passengers.

Front passenger seat; 65 or older
Front passenger seat; Ages 18-64
Rear seat; 65 or older
Rear seat; Ages 18-64

80.0
60.0
40.0
20.0
0

Seat

Other vehicle
Door andinteriors
window glass

Dashboard
vicinity

Rear seat; 65 or older
Rear seat; Ages 18-64

60.0
40.0
20.0
0

Seat

Other vehicle
Door andinteriors
window glass

Dashboard
vicinityFig.15 Rate of fatal and serious injuries toabdomen by injuring vehicle parts
Rate of fatal andserious injuries (%)

Rate of fatal andserious injuries (%)

Fig.14 Rate of Fatal and Serious Injuries to
Chest by Injuring Vehicle Parts

Front passenger seat; 65 or older
Front passenger seat; Ages 18-64

80.0

Fig.16 Rate of fatal and serious injuries toarms by injuring vehicle parts

Front passenger seat; 65 or older
Front passenger seat; Ages 18-64
Rear seat; 65 or older
Rear seat; Ages 18-64

80.0
60.0
40.0
20.0
0

Seat

Other vehicle
Door andinteriors
window glass

Dashboard
vicinityFig.17 Rate of fatal and serious injuries tolegs by injuring vehicle parts■What type of injury condition is caused most frequently that is applicable to all theabove-mentioned situations?
Fig.18 and Fig.19 show the composition ratio of injury condition for front passenger seat and rear seat respectively
by the body parts mainly injured. Apparently, fracture ratio is high in both front and rear seats in case of chest injury
while rupture of internal organs is high in rear seats as well. In case of abdomen injury, rupture of internal organs
occurred more often in both front and rear seats with the ratio exceeding 60% in rear seats whereas over 90% of
the arm and leg injuries were fractures.

100.0

Rupture of internal organs

613 people
8.8

80.0

98 people

Laceration
189 people

Others203 people

19.4
15.3

60.0
40.0

85.6

20.0
0

43.9

95.8

91.6

21.4
Chest

Abdomen

Arms

Legs

Fig. 18 Injury condition of older front seatpassengers by body parts mainly injured

ITARDA INFORMATION no.104

Fracture

Composition ratio (%)

Composition ratio (%)

Fracture

100.0
80.0

Rupture of internal organs

154 people

55 people

8.4

12.7
10.9

Laceration

Others57 people

61 people

63.6

96.5

90.2

12.7
Abdomen

Arms

Legs

60.0
40.0

76.0

20.0
0

Chest

Fig. 19 Injury condition of older rear seatpassengers by body parts mainly injured

ITARDA INFORMATION no.104

5 Characteristics deduced from Case Examples
Based on the analysis so far it can be said about the fatal and serious injuries in older passengers who wore seatbelts that, chest injuries were higher in terms of absolute number whereas abdomen injuries were higher in termsof the rate. Nevertheless, in order to find out other injury factors that were not covered in our Traffic Accident
Research Database, we investigated our In-depth Case Studies (hereafter ‘microdata’). The effects of 1) differencein physiques of older passengers and 2) unusual factors※5 were studied.
Microdata for a period of 10 years from 2003 through 2012 on frontal vehicle collisions that resulted in fatal andserious injuries in older passengers wearing seat belts were examined. Though little in number, 17 relevant cases
were analyzed and the following characteristics were deduced (this includes hip injuries).

■Difference in physiques of older passengers
Case examples of older passengers with a small frame less than 155 cm derived from the average height of older men
and women※3 were studied. Table 4 and Fig. 20 indicate that out of twelve older passengers with fatal and serious
injuries in chest, abdomen or hip, eight were small framed and their injury conditions varied. However, difference inphysiques had little effect on the fatality rates or serious injury rates due to injuries to these body parts. These results
suggest that older passengers with small frames are more likely to get injured in chest, abdomen or hip due to seat belts.
※3 Average height of older population aged 65-79 based on the Health and Nutrition Survey conducted by the Ministry of Health,
Labor and Welfare in 2010 and 2011: Men: 163 cm Women: 150 cm

Injuries to chest, abdomen, hip
Injuries to other body parts

Table 4 Injury condition※4 basedon difference in physiques
No. of fatal and serious injuries
Injuries to chest, abdomen, hip

Chest
Injury condition(injured due
to seat belt)
Abdomen

Hip

HeightLess than 155 cm 155 cm or more
10 people
5 people
8 people4 people
Sternal fracture
Rib fracture
Rib fracture
Heart injury
Lung injury
Abrasion
Vascular injury
BruiseIntrathoracic injury※厚生労働省
Bruise※厚生労働省
Injury to Pancreas
Liver injury
Retroperitoneal injury Lacerated wound※厚生労働省
Lacerated woundPelvic fracture
Intrapelvic injury※厚生労働省
Lumbar spine fractureLess than155 cm5 fatalities

Height155 cmor more3 fatalities
0

2

4

6

8

10

12

No. of fatal and serious injuries

Fig. 20 Injury condition by differencein physique and fatalities■Unusual factors※5
Table 5 and Fig. 21 show that the rate of injuries to chest, abdomen and hip is more than 80% in the presence of
unusual factors※5, whereas the rate is 60% in their absence and that many such injuries proved fatal.

Table 5 Injury condition etc.※4 in Presenceof Unusual Factors※5
No. of fatal and serious injuries
Injuries to chest, abdomen, hip

Chest
Injury condition(injured due
to seat belt)
Abdomen

Hip

Unusual factors
Present
Absent7 people
10 people
6 people
6 people
Rib fracture
Rib fracture
Sternal fracture
BruiseLung injury
AbrasionHeart injury
Lacerated wound
Vascular injury※厚生労働省
Intrathoracic injury※厚生労働省
Retroperitoneal injury
Liver injury
Pancreatic injury Pancreatic injury
膵臓損傷
Lacerated wound
Intrapelvic injury
Pelvic fracture※厚生労働省
Lumbar spine fracture

Injuries to chest, abdomen, hip
Injuries to other body parts

Present
5 fatalities

Unusualfactors
Absent3 fatalities
0

2

4

6

8

10

12

No. of fatal and serious injuries

Fig.21 Injury condition in presenceof unusual factors and fatalities※4 Injury condition also includes other injuries which did not result in fatal or serious injuries.
※5 Unusual factors include cases like cushion was placed on the seat, seat was reclined, seat slider was dislocated etc.

ITARDA INFORMATION no.104

lSpeciafeatureInjuries to Older Passengers in Traffic Accidents~How can we reduce the risk of fatalities and serious injuries? ~6 Conclusion■Characteristics of Injuries to Older Passengers in Accidents
・ Seat belts prove effective for older passengers regardless of their seat positions, but are less effective ascompared to that of younger passengers.
・ Despite wearing seat belts, older passengers are more likely to sustain fatal or serious injuries as follows and the injury
condition in such cases are mostly fractures for the chest, arms and legs whereas rupture of internal organs for abdomen.
1) Fatal and serious injuries in frontal vehicle collisions: By absolute number chest injuries are high whereas byrate abdomen injuries are high.
2) Accidents with “collision speed” (variance in speed before and after collision) ranging from 11km/h to 50km/h or less:Rate of fatal and serious injuries begin to show an increase from a lower collision speed as compared to thatof younger passengers.
3) In accidents where “seats” and “other vehicle interiors” inflict injuries, seat belts are the causes in most cases.
・ Microdata indicate that
1) Rate of older passengers with small frame sustaining injuries in chest, abdomen and hip due to seat belt is high.
2) Rate of sustaining fatal injuries to chest, abdomen and hip owing to the placement of cushions on the seats etc., is high.

■How to reduce the risk of fatal and serious injuries in older passengers
Starting with the obvious, always encourage them to wear seat belts correctly regardless of their seat positions.
However, there are can be various reasons as to why they are not seated properly or not wearing their seat belts
properly. Therefore, we urge drivers and other co-passengers to pay attention to the following points.
◇ Are they seated properly?

It is possible that gap has developed between the hip and the seat back causing backward tilting of the pelvis
due to factors such as back of the knee hitting the front edge of the seat preventing passengers with small frame
to sit deep, slumped posture due to old age etc. (See fig.22).
Also reclining the seat too much will lead to similar condition. In such cases, the seat belt in the hip region tends
to ride up increasing the risk of hip injury. In order to avoid the dislocation of seat belt in the hip region, ensure
correct sitting posture by erecting the seat back as much as possible, providing cushion for back and hip support
and the like. (Do not overdo as the situation may differ from person to person.)◇ Check for any unfastened or slippery cushion placed on the seat.
Case examples of accidents reveal that cushion may slide the hip forward causing the seat belt to ride up which
may result in serious injuries to abdomen and chest. If the cushion is unavoidable ensure that it is fastened
properly and is not slippery.
◇ Is the seat position drawn too forward?
Contact with dashboard vicinity has caused many arm and leg injuries to older passengers on the front seat.
Also, drawing the seat too forward may retard the view of the driver by creating a dead angle. So ensure that theseat is adjusted slightly backward than the driver seat.

Secure the lap
belt across thehips firmly

Pelvis tilts backwards when sitting
shallow which causes the lap belt
to dislocate from the hip easily

Gap

Fig.22 Better sitting posture

ITARDA INFORMATION no.104

Keep the seatback as erect
as possible
Leave no gap
between theseat back andyour back andhip portions

ITARDA INFORMATION no.104
In the above section, actions that need to be undertaken with immediate effect were mentioned. Nevertheless,since the older population would continue to grow, vehicle accessory manufacturers are expected to further
develop user-friendly seat-belts and new restraint and vehicle systems going forward.
However, purchasing a new vehicle would be a personal decision and is something that cannot be done right away;
as such we recommend the use of seat belt cushions or chest protectors that can be easily worn by thepassengers! We explored the availability of shock-absorbing protectors for adult passengers but were unable tofind any. Nevertheless, we did come across shock-absorbing pads in Europe that is meant for child seats to protect
the neck from impacts which is used by sliding it through the seat belt.
In Japan, many chest protectors for motorcycle riders and chest pads for baseball players are commerciallyavailable. Taking reference from such products going forward, we may expect the development and disseminationof products that can help reduce injuries to older passengers of 4-wheeled vehicles.

（ Motoki Tanaka ）Proper use of Seat belts
Securing the seat belts properly will significantly reduce the damages of a traffic accident.

●Keep the seat back in an erect position and sit deep.
●Maintain a correct body posture without leaning to sides.
●Secure the shoulder belt (in case of a typical 3-point
seat belt) firmly away from the neck.
●Ensure the belt is not twisted.
●Insert the buckle into the slot properly.
●Adjust the lap belt firmly across your hips.
Reference: Proper use of seat belts (excerpt from National Police Agency website)

当センターは、平成４年（１９９２年）に国家公安委員会、運輸省（当時）、建設省（当時）から設立許可を受けて、公益法人として設立されました。
その後平成２４年（２０１２年）
４月に公益財団法人に移行しました。我が国で唯一
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公益財団法人 交通事故総合分析センター
お問合せ先●ウェブサイト http://www.itarda.or.jp/●Eメール koho@itarda.or.jp
つくば 交通事故調査事務所〒101-0064
東京都千代田区猿楽町2-7-8 住友水道橋ビル8階
TEL 03-5577-3977(代表) FAX 03-5577-3980

ITARDA INFORMATION no.104