ITARDA 22th Work Shop Report2019
22nd Presentation Session for Traffic Accident Investigations, Analysis, and Research

Accident characteristics of crossing collision accidents by elderly people
Takahiro Narikawa
Senior Researcher, Research Division

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ITARDA 22th Work Shop Report1.

Current status of and trends in accidents as a whole

1-1. Trends in accidents as a whole

No. of elderly people (people)

No. of non-elderly people (people)
Percentage of fatally or seriously injured persons (%)

Record lows were recorded in 2018 for both the number of fatalities at 3,532 people and the number of casualties
at 529,378 people. The government target for road traffic safety that was established in the Tenth Traffic Safety
Basic Plan1) from 2016 called for achieving the safest road traffic seen anywhere in the world by reducing fatalities
from traffic accidents to 2,500 people or less a year and the number of casualties from the same to 500,000 or lessby the year 2020. Yet in response to this, thePercentage of fatallyor seriously injured
situation over achieving the target for fatalities
persons
Number of fatalities
has proven difficult, and further reductions must
be made to both the number of fatally or seriously
injured persons as well. Looking at a breakdownof this by circumstances reveals thatapproximately one-quarter of these cases involve
people riding in a four-wheel vehicle, with thecomposition rate for this remaining largely
unchanged compared with ten years ago. Dealing
with passengers of four-wheel vehicles iscurrently regarded as an important component of
this.
(year)(year)
Non-elderly
people1-2. Trends in passengers of four-wheel
vehicles by age

Early-stageelderly people

Latter-stageelderly people

Fatalities, seriously injured persons, and casualties age 18 or older from 2000 - 2018;vehicle-vehicle and single vehicle accidents; riding or transporting cargo in medium /kei sized vehicles

290 - 94

95 and older

85 – 89

80 – 84

75 – 79

70 – 74

65 – 69

60 - 64

55 – 59

50 – 54

45 – 49

40 – 44

35 – 39

25 - 29

30 – 34

18 – 24

Fig. 1. Trends in fatalities and the percentage ofTrends in fatalities and the rate of fatalities /fatalities / serious injuries for passengers riding in fourserious injuries for passengers riding in fourwheel vehicles by age groupwheel vehicles (when riding in medium-sized or
kei sized vehicles or using them to transport cargo) are shown in Fig. 1 for the respective groups of non-elderly
people (ages 18 - 64), early-stage elderly people (ages 65 - 74), and latter-stage elderly people (ages 75 and over).
While fatalities are in decline among non-elderly people, they are rising among latter-stage elderly people andholding steady among early-stage elderly people.
Trends in the age composition for fatallyor seriously injured persons
What is more, the rate of fatalities / serious
Early-stage
injuries, which indicates the share of persons
First baby boomer
elderly people
Latter-stage
generationelderly people
suffering fatalities or serious injuries from among
Age group with the mostthe number of casualties, has been increasing thefatally or seriously
injured persons
further up in age a person is over these past
several years.
A detailed breakdown of the age composition of
fatally or seriously injured persons is shown in
Fig. 2. While this has declined significantly for
non-elderly people, the rate of decline among
early-stage elderly people has been limited and it
has even increased for latter-stage elderly people
Fatally or seriously injured persons age 18 or older in 2003, 2008, 2013, and2018; vehicle-vehicle and single vehicle accidents; riding or transporting cargodepending on their age range. Up until now, it had
in medium / kei sized vehicles
been the youngest age group that had suffered theFig. 2. Trends in the age composition of fatally or seriously
most fatalities / serious injuries, but in 2018
injured persons who were passengers in four-wheel vehicle

ITARDA 22th Work Shop Reportpeople between the ages of 65 - 69 (corresponding
2003
2018
to early-stage elderly people) suffered these theLatter-stage
Latter-stageelderly people
Early-stageelderly people
most. The fact that the first generation of baby
elderly people
boomers2) (born between 1947 - 1949), which has
Early-stageelderly people Non-elderly
formed the peak of the demographic groups, has
Non-elderly
peoplepeoplereached old age is one factor pushing this further
up the age range. As a result of such circumstances,
the share of elderly people accounting for fatally or
Fatally or seriously injured persons age 18 or older in 2003 and 2018; vehiclevehicle and single vehicle accidents; riding or transporting cargo in medium /seriously injured persons among the passengers ofkei sized vehicles
four-wheel vehicles has doubled over the past 15
Fig. 3. Share of elderly people accounting for fatally
years to now account for 40% of the total, as shownor seriously injured persons among the passengers ofin Fig. 3.
four-wheel vehicles
From the above, the presumption is that the trends
with aging will advance further in the future. Based on such circumstances, finding a way to reduce the number offatally or seriously injured persons among elderly drivers, for which the share continues to rise, is an important
challenge when it comes to reducing fatalities from traffic accidents.
2.

Problems for elderly drivers in traffic accidents

2-1. Problems caused by aging
There are generally two types of problems thought to occur with elderly drivers. Fig. 4 shows the process from thedriving behavior leading up to an accident to how the vehicle functions during an accident and the injuries sufferedby the passengers of the vehicle. When it comes to driving behavior, drivers employ a series of functions that include
cognition, judgment, and steering in order to attempt to avoid accidents. However, since driving ability deteriorates
as a result of the declining mental and physical functions that accompany aging,3)-5) the risk of accidents increases.
Moreover, in cases where the driver was unable to avoid a collision that resulted in an accident, depending on thevehicle there may be functions that come into play to mitigate the damage, or absorb the impact and protect thepassengers when a collision does occur. However, these serve to pass along a shock to the human body as a result.
Since the body's resilience declines as one ages, such cases present an increased risk of an injury occurring.

VehicleHuman
Driving behavior
Cognition

Judgment

Detect hazard

Injury occurs

Avoid
collision
Mitigate harm

Detect risk
Determinecourse of action

Steering

Human

ImpactImpactTake action
Absorb shock
Restrainpassengers

Decline in driving ability

Decline in physicalresilienceFig. 4. Causes of accidents and their outcomes3

ITARDA 22th Work Shop Report2-2. Decline in driving ability
Fig. 5 shows the ratio of primary parties and secondary parties to accidents for each age range in five-yearincrements when it comes to the passengers of four-wheel vehicles in vehicle-vehicle and single vehicle accidents.
The primary party is the side that served to cause the accident, and so presumably there is a higher likelihood that
their driving behavior was more problematic compared with that of the secondary party. Since the share of primaryparties rises the higher up in age you go, this could potentially indicate the manifestation of a decline in driving
ability accompanying aging.
Share of primary and secondary parties
Secondary parties

90 - 94

85 – 89

80 – 84

75 – 79

70 – 74

65 – 69

60 - 64

55 – 59

50 – 54

45 – 49

40 – 44

35 – 39

30 – 34

25 - 29

18 – 24

Primary parties

2018

Fatally or seriously injured persons among the primary and secondary parties age 18 or older in 2018; vehicle-vehicle
and single vehicle accidents; riding or transporting cargo in medium / kei sized vehicles

Fig. 5. Composition rate of primary parties to secondary parties by age group

2-3. Decline in physical resilience

Risk of occurrence

When it comes to the decline in physicalInjury risk curve for the chest area
resilience, it is commonly known that thestrength of one's bones declines as one ages.6)
65 years old
Fig. 6 is a diagram known as an "Injury risk
curve,"7) which expresses the risk of a person
suffering a chest injury and the connection
35 years old
with indicators of injury. Chest deflection,
which indicates the risk of fracturing one's
ribs, is one indicator of injury to the chest area.
This is indicated along the horizontal axis. The
Chest deflection
risk of injury occurring is indicted by the AIS
Laituri 2005
scale, which is a simple indicator of injury.
Fig. 6. Injury risk curve
The risk of an injury at or above the level ofan AIS3, which indicates a fracture of three or more ribs and which corresponds to a serious injury, is shown along
the vertical axis. The fact that a 35-year old has a 15% probability of suffering from such an injury when there is achest deflection of 42mm, whereas a 65-year old has a slightly less than four-fold probability of this at 50% withthe same chest deflection, serves as confirmation of the greater risk faced by those in old age.
This study analyzed the driving characteristics and quality of injuries of elderly drivers from two dimensions: theincreased risk of accidents caused by a decline in one's driving ability due to aging, as well as the increased risk of
injury caused by a decline in physical resilience.

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ITARDA 22th Work Shop Report3.

Characteristics of Accidents Caused by Elderly Drivers

3-1. Characteristics of accidents
A breakdown of the types of accidents involving fatally or seriously injured persons caused by elderly drivers isshown in Fig. 7. Crossing collisions, head-on collisions, and single vehicle accidents with roadside structures
account for 70% of fatally or seriously injured persons. In particular, crossing collisions and single-vehicle accidents
with roadside structure account for a large share of these compared with non-elderly people. Next, these three
accident types will be analyzed in terms of the human factors leading to them and the degree of the impact sustained
from the perspectives of driving ability and physical resilience.
Composition rate of the types ofaccidents caused by elderly people
Other single-vehicle
Other vehiclevehicle
While
Whileturning
turningrightright

Crossing
collisions

Composition rate of the types of accidents
caused by non-elderly people
Other single-vehicle
Other vehicle- Whilevehicleturningright

Crossing
collisions

Rear-end
Head-oncollisions

Rear-end

Single vehicle:
Roadside structure

Single vehicle:
Roadside structure

Head-oncollisions

Fatally or seriously injured persons who were primary or secondary
parties age 18 or older in 2018; vehicle-vehicle and single vehicle
accidents; riding or transporting cargo in medium / kei sized
vehicles; for the part of the vehicle that suffered the collision,
secondary collisions to the front, sides, and rear were excluded;
excluding trains

Fig. 7. Composition rate of the types of accidents caused by each age group

3-2. Human factors
A breakdown of the human factors behindthese three accident types is shown in Fig. 8. A
No human factors
failure to confirm safety factors accounts forOperating error
75% of crossing collisions, with a large
Traffic environment
proportion of these being due to cognitive
Predictive failure
errors. A failure to pay attention to what is up
Failure to observe surrounding
traffic movement
ahead serves as the primary cause of head-on
Failure to confirm safety
factors
collisions, while driving operation error
Failure to pay attention
forward: External(operating error) is the primary cause for
Failure to pay attention
forward: Internal
collisions with roadside structures. The decline
Crossing
Roadside
Head-oncollision
structurecollisionin one's driving ability due to aging can be
Fatal / serious injury accidents in 2018; primary party age 65 or older;considered for each of these. With the failure toriding or transporting cargo in medium / kei sized vehicles
confirm safety factors in crossing collisions in
Fig. 8. Human factors behind accidents by elderly people
particular, there is a vast range to cover and therisk of errors is potentially enormous.
On the other hand, the recent advances in support technologies for errors by the vehicles themselves have beenremarkable, with progress being made on their practical implementation as advanced safety technologies.8) For
example, it is conceivable that accidents like head-on collisions and collisions with roadside structures due to drivers
deviating from their lanes could be reduced through advanced safety technologies such as lane deviation prevention

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ITARDA 22th Work Shop Report

devices. However, as was mentioned above, with cognition when it comes to crossing collisions there is a vast range
to cover and a wide range of phenomena. Therefore, it will presumably take time in order to reduce the number ofcrossing collision accidents via this, and this will require priority initiatives in the future.
3-3. Degree of impact

Fatally or seriously injured
person distribution

Fatally or seriously injured
person distribution

Frequency

The Barrier Equivalent Velocity is
Crossing collision
Head-on collisions
used as an indicator for the degree of
Average: 42km/h
Average: 28km/h
impact. The Barrier Equivalent
Velocity indicates the speed thatwould produce the same amount of
deformation as an actual accident
when there is a collision with a fixed
wall. Using this, the degree of impact
can be compared for two different
Barrier Equivalent Velocity (km/h)
Barrier Equivalent Velocity (km/h)
types of collision phenomena by
Micro data from 2006 - 2016; AIS1+; riding or transporting cargo in medium / kei sized vehicles;age 18 or older; in front of the vehicle suffered from the collision; crossing collisions: N=481,
excluding factors such as the weighthead-on collisions: N=579, collisions with roadside structures: N=379
and speed of the other party to theFig. 9 Comparison of the Barrier Equivalent Velocities
collision.
The distribution for Barrier
Head-on collisions
Crossing collision
Equivalent Velocities from crossing
Non-elderly
Non-elderly
peoplepeoplecollisions and head-on collisions
Elderly
Elderlywhen the region of the collision is thepeoplepeoplefront of the vehicle as calculated
from the micro data is shown in Fig.
Elderly
9. With head-on collisions, thepeopledistribution of Barrier Equivalent
Velocities is heavily tilted towards
the high-speed range, with theDanger perception speed (km/h)
Danger perception speed (km/h)
average for all speeds coming to
A danger perception speed of 20km/h refers to a speed range of over 10km/h up to 20km/h
42km/h. Conversely, with crossing
Fatally or seriously injured persons who were primary or secondary parties age 18 or older in 2018;
medium / kei sized vehicles; for the part of the vehicle that suffered the collision, secondary collisions tocollisions this is heavily tilted
the front were excluded
towards the low-speed range, with a
Fig. 10. Danger perception speed distribution
low average for all speeds of
14km/h. In other words, due to the high degree of impact on elderly people, who have diminished physical resilience,from head-on collisions and collisions with roadside structures, these constitute harsh conditions for them. This isbelieved to be one of the reasons for their prevalence of fatally or seriously injured persons. What is more, when
the distribution for the danger perception speeds is compared for crossing collisions and head-on collisions by age
range, virtually no difference was observed by age range with head-on collisions, as indicated in Fig. 10. However,with crossing collisions elderly people were overly inclined to view relatively lower speed ranges as being
dangerous compared with non-elderly people. To put this another way, despite the fact that crossing collisions
constitute conditions with a low degree of impact for elderly people, they account for a large share of fatally or
seriously injured persons. This could potentially be because the elderly often tend to sustain injuries from them dueto their lower physical resilience.
From the results thus far, the thinking is that the crossing collision accidents that account for a large share of thefatally or seriously injured persons among elderly drivers are significantly affected by the decline in driving ability

6

ITARDA 22th Work Shop Reportcaused by aging. What is more, there is also the conceivable possibility that elderly drivers drive at lower speeds tocompensate for their declining cognitive functions. On the other hand, compared with head-on collisions andcollisions with roadside structures, which feature a high degree of impact, these presumably constitute conditions
in which the effects of a decline in physical resilience are more readily apparent. Therefore, with crossing collisions
it will be necessary to concretely specify the status of cognitive errors from the perspective of human factors, aswell as the situation concerning what sorts of injuries occur at low degrees of impact from the perspective of thedegree of impact. Following this, an analysis will be performed on the status of accidents caused by cognitive errors
and the extent to which injuries occur during crossing collision accidents.
4.

Accident Considerations and Thoughts on Dealing with Them

4-1. Driving behavior during crossing collision accidents
To begin with, the driving behavior from crossing
collisions will be analyzed for both non-elderly people andSecondary party
elderly people. For this, the distribution of danger
Secondary party
perception speeds was investigated for both primary andsecondary parties and by whether or not signal control was
involved. As the primary party is the side that served tocause the accident, there is the possibility that their driving
behavior will differ from that of the secondary party, who
Primary party
unwittingly became involved in the accident. An image ofthe crossing collision accident conditions is shown in Fig.
Fig. 11. Diagram of the conditions of a crossing
11. It shows an accident between a primary party
collision accident (no signal control)
attempting to travel straight in an upward direction fromthe bottom of the road diagram and a
Elderly people
Non-elderly people
secondary party crossing the intersection.
Left  right
The direction of the secondary party was
Left  rightanalyzed by whether they were coming fromthe left or right.
The distribution for the danger perception
speeds of secondary parties when there is no
signal control (70% of the tabulated
conditions in question) is shown in Fig. 12.
Danger perception speed (km/h)
Danger perception speed (km/h)
The blue indicates a secondary party
Fatally or seriously injured persons who were secondary parties age 18 or older from 2009 - 2018;crossing collision with no signal control; medium / kei sized vehicles; part of the secondary party's
heading from left to right, while orange
vehicle that suffered from the collision was the front and the side in the direction of motion of the
primary party; primary party driving a four-wheel vehicle or motorcycle
shows them heading from right to left. The
results indicate a mountain-shaped
Fig. 12. Speed distribution for the secondary party
distribution centered primarily around awhen there is no signal control
speed range of over 30km/h up to 40km/h(hereafter, this will be denoted by using 40km/h to represent the highest speed). No major differences were observedin the distribution trends based on age range or the vehicle's direction of motion. This is estimated to be because thesecondary party did not envision that the primary party would encroach into the intersection, and was proceeding
along with the flow of traffic.
The distribution for the danger perception speeds of primary parties when there is signal control (27% of thetabulated conditions in question) is shown in Fig. 13. The assumption was made that the secondary party was comingfrom the left, as it would conceivably make it more complicated for the primary party to confirm the direction ofStop

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ITARDA 22th Work Shop Report

the secondary party had they been coming
Non-elderly people
Elderly people
from the right. The results were similar to
those with the secondary parties listed above,in that it formed a mountain-shaped
distribution that peaked at 40km/h, with thesame tendency seen regardless of the age
range. It is conjectured that the results weresimilar to the circumstances with theDanger perception speed (km/h)
Danger perception speed (km/h)
secondary party because they could proceedof the primary partyof the primary party
without becoming aware that a vehicle wasFatally or seriously injured persons who were primary parties age 18 or older from 2009 2018; crossing collision with signal control; medium / kei sized vehicles; part of theapproaching from either direction since signal
primary party's vehicle that suffered from the collision was the front and the side in the
direction of motion of the secondary party; secondary party driving a four-wheel vehicle orcontrol was in effect.
motorcycle
The distribution for the danger perception
Fig. 13. Speed distribution for the primary party
when there is signal control
speeds of primary parties when there is no
signal control (73% of the tabulated conditions in question) is shown in Fig. 14. The speed peak tended to be lower
with them than with the secondary parties on the whole. This tendency was particularly pronounced with elderly
people. The danger perception speeds of early-stage and latter-stage elderly people versus the share from non-elderly
people are shown in Fig. 15. Latter-stage elderly people have a larger share of this in the medium to lower speed
range (40km/h or less), with the tendency to enter intersections at lower speeds becoming more pronounced theolder one gets. It is conceivably possible that this is because since it takes more time to make confirmation due tothe decline in their cognitive function, they took compensatory actions such as reducing their speed to ensure easeof confirmation.

(People)Non-elderly people

Danger perception speed (km/h)
of the primary party(People)Early-stage elderly
peopleDanger perception speed (km/h)
of the primary party(People)Latter-stage elderly
peopleDanger perception speed (km/h)
of the primary party

Fatally or seriously injured persons who were primary parties age 18 or older from 2009 - 2018; crossing collision with no signal
control; medium / kei sized vehicles; secondary party driving a four-wheel vehicle or motorcycle

Fig. 14. Speed distribution for the primary party when there is no signal control

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ITARDA 22th Work Shop Report

From the above, it was learned that primary parties
Early-stage elderly people
where there is no signal control have the potential
Latter-stage elderly people
to be affected by a decrease in driving ability
resulting from aging. Under such circumstances, itwould potentially be possible to effectively reduce
accidents by supporting the cognitive functions ofdrivers with respect to vehicles approaching fromthe left or right side. Consideration has also been
Danger perception speed (km/h) of the primary party
given to autonomous vehicle detection for
Fatally or seriously injured persons who were primary parties age 18 or older
vehicles approaching from the left or right sides
from 2009 - 2018; crossing collision with no signal control; medium / kei sized
vehicles; fatally or seriously injured persons who were primary parties age 18 or
via radar, cameras, and other equipment installedolder from 2009 - 2018; crossing collision with no signal control; medium / kei
sized vehicles
on one's vehicle. A method of detecting otherFig. 15. Speed distribution for the primary party whenvehicles via communication between vehicle there is no signal control (ratio versus non-elderly people)
detection devices installed on other vehicles
approaching from the side and on the road has also been taken into consideration via vehicle-to-vehicle and roadto-vehicle communication devices.9) The presumption is that these sorts of devices can effectively reduce accidents
by providing notification to the driver.
4-2. Status of injuries occurring from crossing collision accidents
Fatally or seriously
The share of major body parts that sustained
injured persons
Crossing collisions(people)injuries on non-elderly people during crossing
Legscollisions for each danger perception speed are
Arms
shown in Fig. 16. The analysis was performed
Lumbar region
when the part of the vehicle that suffered from the
Backcollision was the front. The most frequently
Abdomeninjured part of the body was the chest area,
Chest
exhibiting a distribution that peaked aroundNeck
40km/h on the whole.
Face
Conversely, the distribution for crossing
Headcollisions and head-on collisions for elderly
people is shown in Fig. 17. The distribution forDanger perception speed (km/h)
crossing collisions is arranged in a trapezoidal
Fatally or seriously injured persons who were primary parties age 18 or older
shape over the low-speed range of 20 - 40km/h.
from 2013 - 2018; medium / kei sized vehicles; part of the vehicle that suffered
the collision was the front
Just the same as with non-elderly people, the partof the body they injured the most frequently wasFig. 16. Share of major body parts that sustained injuries on
the chest area, which accounted for roughly 50%
non-elderly people during crossing collisions for each speedof the injuries from crossing collisions across all
speed ranges. In addition, for head-on collisions this is distributed in a mountain-like shape peaking at 50km/h. A
similar trend was seen here with non-elderly people as well, with no difference observed. Compared to with headon collisions, with crossing collisions a roughly equivalent composition and number of injuries was seen in both the
20km/h and under speed range as with the 40km/h one, with the decline in resilience due to aging thought to be one

9ITARDA 22th Work Shop Reportfactor behind this.
Fatally or seriously
injured persons(people)Fatally or seriously
injured persons(people)Crossing collisions

Head-on collisions
Legs

Chest injuries
were the mostcommonArms
Lumbar region

Chest

Back
Abdomen
Chest
Neck
Face
Head

Danger perception speed (km/h)

Danger perception speed (km/h)

Fatally or seriously injured persons who were primary parties age 18 orolder from 2013 - 2018; medium / kei sized vehicles; part of the vehicle
that suffered the collision was the front

Fig. 17. Share of major body parts that sustained injuries on elderly people during crossing collisions andhead-on collisions for each speed

The results of an analysis from micro data from 2006 - 2016
on the parts that caused the damage with injuries to the chest
area are shown in Fig. 18. When the level of injury wasdeemed to be AIS2+, which is the level of a rib fracture, thenin most cases the injuries in crossing collisions and head-on
collisions (limited to collisions involving the front of thevehicle in both cases) were due to the seat belt, with these at
74% and 39%, respectively. A trait that seat belts must haveis that they must involve minimal damage.

Share of damage from one's
seat belt
AIS2+ chest injuries:

Crossing collisions: 74%
Head-on collisions: 39%
Micro data from2006 - 2016
Frontal collisions
Passengers age 18 or older

Fig. 18. Part that caused the damage withinjuries to the chest area

4-3. Protective features for passengers for crossing collision accidents
The working condition of the restrain systems equipped on a vehicle should be confirmed in order to cut down on
injuries. Table 1 shows the operating rate for airbags in seats equipped with them for each danger perception speed
across the top, as well as the number of fatally or seriously injured persons across the bottom (for collisions where
the front of the vehicle was the section that collided). Normally, automobile manufacturers design airbags and otherrestraint systems to operate in collisions against a fixed barrier at speeds of 20 - 30km/h or greater.10)
With head-on collisions, the deployment rate within the speed range of 30km/h is 72%. With collisions with roadsidestructures, their operating rate is largely identical at 76%. Here, if we were to assume that 72% is the manufacturers'
intended operating deployment rate, then a similar operating rate would be achieved in crossing collision accidents
at a speed of 60km/h.

10ITARDA 22th Work Shop Report

Table 1. Air bag deployment rate for fatal or serious injury accidents and fatallyor seriously injured persons
Dangerperception speed(km/h)
Head-on collisions

Restraint device
operating rate(frontal collision
air bags, seat belt
pretensioners)

Crossing collisions

Fatally or seriously
injured persons

Head-on collisions

Collisions withroadside structures

Coverage rateCrossing collisions
Collisions withroadside structures
Fatally or seriously injured persons who were primary or secondary parties age 18 or older from 2013 - 2018; medium / kei sized vehicles;
part of the vehicle that suffered the collision was the front with no secondary collision; wearing a seat belt; vehicle equipped with air bag
system

At the same time, if the same intended operating range were indicated for the lower column, then roughly 95% ofhead-on collisions would be covered whereas only 10% of crossing collision accidents could be covered.
The above indicates that the only restraint system for crossing collisions in the medium to low-speed range are seatbelts. With elderly people in particular, this could conceivably increase their risk of injury when coupled with theirdeclining physical resilience. What is more, since pretensioners do not work at medium to low speeds, this could
potentially lead to insecure restraint of the passenger due to delays in the initial restraint being applied. Having
pretensioners go into operation during crossing collisions could be done in an effort to ensure secure restraint of thepassenger during crossing collision accidents, where there is a diverse array of collision conditions, and could
possibly be expected to improve the protective features for passengers.
5.

Summary

In terms of overall trends:
1
The number of fatalities among elderly passengers of four-wheel vehicles has not declined.
2
The situation must be handled from the dual dimensions of the decline in driving ability and the decline inphysical resilience.
The characteristics of crossing collision accidents involving elderly people and future responses include:
3
Responding to crossing collision accidents that involve fatally or seriously injured persons is challenging.
 The decline in driving ability is thought to have an effect on primary parties where there is no signal control.
When driving straight, the older one gets the greater the share of people who drive in the medium to low
speed range.
 A large number of injuries occur within the medium to low-speed range.
Injuries to the chest area in particular account for half of the total, with much of this due to seat belt injuries.
4
The situation must be handled from the dual dimensions of the decline in driving ability and the decline inphysical resilience.
 Notification functions / cognitive support from vehicle-to-vehicle communication, etc.
 Improving the operating rate of restraint systems will improve the early restriction of passengers.

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会 公財)交通事故総合分析センター
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frontal impacts (No. 2018-22-0004). SAE Technical Paper.
7) Laituri, T. R., Prasad, P., Sullivan, K., Frankstein, M., & Thomas, R. S. (2005). Derivation and evaluation ofa provisional, age-dependent, AIS3+ thoracic risk curve for belted adults in frontal impacts (No. 2005-010297). SAE Technical Paper.
8) 経済産業省. (2019).サポカー／サポカーＳ(安全運転サポート車)のＷＥＢサイト.
https://www.safety-support-car.go.jp/
9) 高度情報通信ネットワーク社会推進戦略本部・官民データ活用推進戦略会議. (2019).
官民 ITS 構想・ロードマップ 2019.
https://www.kantei.go.jp/jp/singi/it2/kettei/pdf/20190607/siryou9.pdf
10) 国土交通省. (2019).自動車安全情報.
https://www.mlit.go.jp/jidosha/anzen/02safetydevice/index.html

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