ITARDA

Institute for Traffic Accident
Research and Data Analysis（財）交通事故総合分析センター
ITARDA INFORMATION

91

No.
0

2011

NOVEMBER

10,00020,00030,00040,000

Number ofcasualties

Crossing collisions

30% 40,258

Collisions while turning right

19% 25,546

49(65,804)

Collisions while turning left

12% 15,956
Rear-end collisions

8% 11,072

Running off the road/Overturning

5% 7,085

Head-on collisions% ofmotorcyclists are
involved in “crossing
collisions” and“collisions whileturning right”

3% 3,199

Collisions with roadside structures

2% 1,892

Others

21% 27,791

Number of casualties by type of accident involving motorcycles

Special feature

Characteristics ofmotorcycle accidents—Beware of overlooking motorcycles—Institute for Traffic Accident Research and Data Analysis

ITARDA
INFORMATION

91

財団法人 交通事故総合分析センター

イタルダ・インフォメーション

2011 NOVEMBER
0

10,00020,000No.

30,00040,000

死傷者数
（人）

出会い頭
30% 40,258人

右折時
19% 25,546人
左折時

追突

路外逸脱・転倒

正面衝突

工作物等

8% 11,072人

5% 7,085人

二輪車死傷事故の12% 15,956人

49（65,804人）%が「出会い頭」と「右折時」で発生しているSpecial feature

Characteristics ofmotorcycle accidents—Beware of overlooking motorcycles—
The number of people involved in traf fic
accidents has been decreasing year by year,
but even so, as many as 56,391 people were
killed or severely injured in 2010. Among thevictims, 16,500, or about one third, wereriding a motorcycle. In this issue of ITARDA
Information, we focus on traffic accidents
involving motorcycles and discuss thecharacteristics of this type of accident.

3% 3,199人

2% 1,892人

その他

21% 27,791人

事故類型別二輪車死傷事故

CONTENTS

1 Introduction
2 Characteristics of motorcycle
accidents

3 Examples of accidents
4 Summary

2

ITARDA INFORMATION 91

二輪車事故の特徴

特集－「見落とし」に注意！ －

CTION
SE

Introduction

1

The total number of traffic accident fatalities(death occurring within 24 hours following theaccident; hereafter the same) has been on asteady decline, from 8,747 in 2001 to 4,863 in
2010, marking a 45% reduction. Almost thesame downward trend can be seen in thenumber of fatalities involving people riding a
motorcycle, from 1,566 to 871 (Fig. 1). Indeed,

the ones most frequently involved in fatal
accidents in 2010 were pedestrians (1,714; 35%),
followed by car drivers (1,602; 33%), motorcycle
riders (871; 18%), and bicycle riders (658; 14%)
(Fig. 2), suggesting that motorcycles do notseem to pose a higher risk of death than othermeans of transportation.

10000
Total
Walking■ Riding in a car■ Riding a motorcycle■ Riding a bicycle
■

9000

■

Number of fatalities

8000
7000
6000
5000
4000
3000
2000
1000
0

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

Fig. 1: Changes in the number of fatalities by means of transportation (2001–2010)
(%)

100

Riding a bicycle

90

658 14%80

Riding a motorcycle

70
60
50

871 18%Riding in a car

1,602 33%

40
30
20
10
0

Walking

1,714 35%
2010

Fig. 2: Number of fatalities by means of transportation (2010)91 ITARDA INFORMATION

3

特集

二輪車事故の特徴－「見落とし」に注意！ －Looking at the severity of injury, however, this is
not the case. Despite the 37% reduction from
24,814 in 2001 to 15,629 in 2010, the number ofpeople severely injured in accidents while riding
a motorcycle has outweighed that of any othermeans of transportation since 2005 (Fig. 3). In

2010, the ones most likely to sustain severe
injury were motorcycle riders (15,629; 30%),
followed by car drivers (14,524; 28%), bicycle
riders (11,317; 22%), and pedestrians (998; 19%)
(Fig. 4).

30000
Total
Walking
Riding in a car■ Riding a motorcycle■ Riding a bicycle

Number of serious injuries

■
■

25000

■

20000
15000
10000
5000
0

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

Fig. 3: Changes in the number of serious injuries by means of transportation (2001–2010)

(%)

100
90

Walking

9,988 19%

80
70
60
50
40

Riding a bicycle

11,317 22%

Riding in a car

14,524 28%

30
20
10
0

Riding a motorcycle

15,629 30%
2010

Fig. 4: Number of serious injuries by means of transportation in 2010

4

ITARDA INFORMATION 91

Characteristics ofmotorcycle accidents

CTION
SE

2

(1) 70% of motorcyclists are the secondary party
Fo r f a t a l a n d i n j u r y a c c i d e n t s i n v o l v i n g
motorcycles and cars, Fig. 5 shows whether
they were the primary or secondary party in theaccident, in percentage terms. “Primary party” isthe most negligent of those first involved in a
traffic accident, or, if the level of negligence isalmost the same, the least injured party.

“Secondary party” is the less negligent of those
first involved in a traffic accident, or, if the levelof negligence is almost the same, the moreinjured party. Motorcycles are more likely thancars to be the secondary party, constituting
70%. In other words, motorcycle riders are
exposed to a higher risk of being a victim in an
accident.

(%)

100■ Secondary party■ Primary party

90
80

38%

70
70%

60
50
40

62%

30
20

30%

10
0

Motorcycle accidents

Car accidents

Fig. 5: Percentage of primary/secondary parties in fatal and injury accidents (2010)(2) More frequently involved in crossing
collisions and collisions while turning right
To examine motorcycle accidents more closely,
the number of fatal and injury accidents
involving a motorcycle is broken down
according to the type of accident in Fig. 6, andthat involving a car in Fig. 7 for comparison.
While rear-end collisions and then crossing
collisions are the two largest groups in the caseof car accidents, motorcycle riders are most
likely to be involved in crossing collisions,followed by collisions while turning right.
Here, 72% and 87% of motorcycles in crossing
collisions and collisions while turning right,
respectively, are the secondary party, suggesting
again that motorcycle riders are exposed to ahigher risk of being a victim in these types ofaccident.

(Cases)(Cases)■ Secondary party■ Primary party

45,00040,00035,00030,00025,00072%

20,0005%

15,00087%

10,000
5,000
0

70%

95%

28%
13%

47%

58%
42%

53%
100%

100%

30%

Crossing Collisions Collisions Rear-end Running off Head-on Collisions Others
collisions while
while collisions the road/ collisions with roadsideturning
turning
Overturning
structures
right
left

Fig. 6: Number of fatal and injury motorcycle
accidents by type of accident (2010)

500,000

Number of fatal/injury accidents

Number of fatal/injury accidents

50,000■ Secondary party■ Primary party

405,000
400,000
350,000

50%

300,000
250,000
200,000

36%

150,000
100,000
50,000
0

64%

25%

50%
28%
72%

9%
91%

53%
100%

47%

100%

75%

Crossing Collisions Collisions Rear-end Running off Head-on Collisions Others
collisions while
while collisions the road/ collisions with roadsideturning
turning
Overturning
structures
right
left

Fig. 7: Number of fatal and injury car accidents
by type of accident (2010)91 ITARDA INFORMATION

5

特集

二輪車事故の特徴－「見落とし」に注意！ －(3) 90% of motorcycles as the secondary party
collide with a car
As shown in Fig. 8, several different parties are
involved in accidents in which the motorcycle isthe primary party, whereas the motorcycle as thesecondary party almost always, or in nine cases
(%)

100
90

24%

out of ten, collides with a car. The reason why
motorcycle riders as the secondary party are
more severely injured may be that around 90%of the other parties are cars, which are heavier
than motorcycles.

2%
2%

5%

■ Others■ None■ Pedestrians■ Bicycles■ Motorcycles■ Cars

80
11%

70
60

20%

50
40

12%
91%

30
20

33%

10
0

Motorcycle as
primary party

Motorcycle assecondary party

Fig. 8: Percentage of other parties in fatal and injury motorcycle accidents (2010)(4) Over 80% of the causes of crossing
collisions and collisions while turning rightare delays in noticing the motorcycle
Let’s look at the causes of the two major types ofmotorcycle accidents, namely crossing collisions
and collisions while turning right. According to
Fig. 9 which shows the human errors committed
by the primary party in accidents in which
motorcycles are the secondary party, “Delay innoticing motorcycle” accounts for more than 80%of the total. Looking into this error in detail, as
shown in Fig. 10, nearly 70% of these delays are
(%)

100
90

5%
10%

12%

70

■ Others■ Driver errors■ Judgment errors■ Delay in noticing

60

40

1%
4%

100 2%
3%
90
80

27%

29%

70
60

85%

87%

50
40

30

30

20

20

10

10

0

Crossing collisions

Collisions whileturning rightFig. 9: Human errors causing crossing collisions
and collisions while turning right involving
motorcycles (2010) (committed by the primary party
with the motorcycle as the secondary party)

6* “Intrinsic” includes dozing and inattentive driving,and “extrinsic” includes adjusting the in-car stereo/
navigation system and distracted driving.
(%)

1%

80

50

caused by an insufficient check on the traffic.
The delay in noticing a motorcycle even after
checking the road safety may be caused by thetendency of car drivers to overlook motorcycles
more easily than cars. A motorcycle accident
analysis conducted in the UK reported that it is
not easy for other road users to notice
motorcycles. This also indicates the need for
motorcycle drivers to be aware of the risk ofbeing overlooked by car drivers and to always
drive safely.

ITARDA INFORMATION 91

068%

Crossing collisions■ Failure to lookahead carefully:
intrinsic■ Failure to lookahead carefully:
extrinsic■ Failure to checksafety■ Insufficient
safety check66%

Collisions whileturning rightFig. 10: Breakdown of the error “Delay in noticing
motorcycle” (2010) (committed by the primary party
with the motorcycle as the secondary party)

(5) More frequently involved in crossing collisions
during daytime hours and collisions whileturning right during nighttime hours
With regard to the time of day when traffic
accidents occur, as shown in Fig. 11, the ratio of
daytime accidents to nighttime accidents isalmost the same, or roughly 7:3 for bothmotorcycles and cars. As shown in Fig. 12, thetype of motorcycle accident most frequently
seen is crossing collisions during daytime hours
and collisions while turning right during
nighttime hours.

(%)

100
90
80

28%

26%

72%

74%

Riding a motorcycle

Riding in a car■ Nighttime■ Daytime

70
60
50
40
30
20
10
0

Fig. 11: Percentage of daytime/nighttime fatal and injury accidents involving cars (2010)

(%)

100

90

80

70

20%

23%

1%
2%

5%
8%

2%
2%

5%
9%

60
14%

8%

50

40

17%

■ Others■ Collisions
with roadsidestructures■ Head-on
collisions■ Running off
the road/
Overturning■ Rear-end
collisions■ Collisions
while turning
left■ Collisions
while turning
right■ Crossing
collisions

26%

30

20

33%
25%

10

0

DaytimeNighttime

Fig. 12: Types of fatal and injury accidents by time of day (2010)91 ITARDA INFORMATION

7

特集

二輪車事故の特徴－「見落とし」に注意！ －(6) Mopeds more frequently involved in crossing
collisions, and small/mini motorcycles incrossing collisions and collisions whileturning rightW i t h r e g a r d to t h e e f f e c t o f t h e t y p e o f
motorcycle on accidents, as shown in Fig. 13,
small-sized (over 250 cc) and mini-sized (over125 cc and up to 250 cc) motorcycles are more
frequently involved in crossing collisions andcollisions while turning right, and for Class 2
mopeds (over 50 cc and up to 125 cc) and Class
1 mopeds (up to 50 cc), crossing collisions are
more prevalent.

(%)

100

90

22%

23%

80
1%
70

1%
3%
8%

1%

2%
5%

1%

2%

9%

5%

5%
9%

11%

50

2%

7%
11%

60

20%

23%

■ Others■ Collisions
with roadsidestructures■ Head-on
collisions■ Running off
the road/
Overturning■ Rear-end
collisions■ Collisions
while turning
left■ Collisions
while turning
right■ Crossing
collisions

13%
11%

12%

17%

40

20%
23%

23%

30

20
34%
10

22%

0

Small-sized
motorcycles

23%

Mini-sized
motorcycles

27%

Class 2 mopeds

Class 1 mopeds

Fig. 13: Types of fatal and injury accidents by type of motorcycle (2010)

8

ITARDA INFORMATION 91

(7) “Daytime running lamps” can reducecrossing collisions
Motorcycle “daytime running lamps” became
mandatory in 1998 to improve the conspicuity of
motorcycles in the daytime with the objective of
reducing traffic accidents. Based on Fig. 14,
there is almost no difference in the number ofcollisions while turning right regardless ofwhether or not the headlamps are used, but inthe case of crossing collisions, the figure isslightly lower when the headlamps are turned
on. From this, the use of headlamps may reduce
the risk of crossing collisions.
Looking at the use/non-use of headlamps in the
total accidents, as shown in Fig. 15, 36% of
motorcycle riders involved did not turn on theheadlamps. It is considered that ensuring theuse of headlamps in the daytime may reduce
the risk of traffic accidents.

(%)

100
90

20%

20%

80
70

1%

1%

3%

3%

5%

5%

8%

8%

14%

13%

60
50
40

16%

17%

■ Others■ Collisions
with roadsidestructures■ Head-on
collisions■ Running off
the road/
Overturning■ Rear-end
collisions■ Collisions
while turning
left■ Collisions
while turning
right■ Crossing
collisions

30
20

34%

32%

10
0

Turned on

Turned off

Fig. 14: Types of fatal and injury accidents involving motorcycles
by use/non-use of headlamps in the daytime (2010)
(%)

100

Unknown/Others 4%

90
80

Turned off 36%

70
60
50
40
30

Turned on 60%

20
10
0

DaytimeFig. 15: Percentage of use/non-use of headlamps in fatal andinjury accidents involving motorcycles (2010)91 ITARDA INFORMATION

9

特集

二輪車事故の特徴－「見落とし」に注意！ －

CTION
SE

3

Examples of accidents

Case 1: Crossing collision[Situation]
At around 9 a.m., a standard-sized passenger
car (A, driven by a 55-year-old man) was slowly
entering a two-lane road from a parking lot bymaking a right turn. The driver glanced to theright and saw no vehicles, so he began to turnright without stopping. As the car proceeded tothe point where its front end was on the road, henoticed a Class 2 moped (B, driven by a 75-yearold man) coming from the right at about 40 km/h.
He immediately stopped the car, but the moped
crashed into the front right side of the car whichblocked the moped’s way.

[Causes]
The driver of the car overlooked the moped
because he did not fully check the traffic, andprobably because he did not stop his car at thatpoint. Another cause may be the moped driver’s
failure to turn on the headlamps.
[Countermeasures]
When entering a road, it is important for car
drivers to always stop and look both ways
carefully. It is also important to turn on the
motorcycle headlamps in the daytime so as not
to be overlooked.

[Injuries]
The driver of the moped escaped head injuries
thanks to wearing a proper helmet, but his chest
hit the road and he suffered serious rib fractures.

Diagram of the crash

B

A

10

ITARDA INFORMATION 91

Case 2: Collision while turning right[Situation]
At around 6 a.m., a mini-sized passenger car (A,driven by a 30-year-old man) was about to makea right turn at a T-junction on a four-lane road.
He turned on the right turn signal and slowed
down; he looked at the oncoming lane and saw
no vehicles except a large truck parked in therightmost lane (seen from the car) on the far
side of the junction. As he began to turn right,
the passenger in his car yelled, “Watch out!”
just as a mini-sized motorcycle (B, driven by a
41-year-old man) coming from the opposite lane
at about 40 km/h crashed into the car.
[Injuries]
The driver of the motorcycle was wearing ahelmet at the time of the accident, but he died
two days later.

[Causes]
The driver of the car overlooked the motorcycle
because he did not fully check the traffic.
Another cause may be that the car driver’s
attention was drawn to the parked truck or tovehicles that might be coming from the road on
the right.
[Countermeasures]
When turning right, car drivers must stop andcarefully check that there are no oncoming
vehicles in the opposite lane. Also, motorcycle
riders must be more careful, and assume they
may be overlooked.

Diagram of the crashParked truckB
A

91 ITARDA INFORMATION

11

Institute for Traffic Accident Research and Data Analysis

二輪車事故の特徴－「見落とし」に注意！ －

CTION
SE

4

ITARDA INFORMATION

特集

Summary

イタルダ・インフォメーション[Characteristics of motorcycle accidents]
1 70% of motorcycle riders involved in traffic accidents are the secondary party.
2 Crossing collisions and collisions while turning right are typical types of accidents
involving motorcycles.
3 When the motorcycle is the secondary party, the other party is a car 90% of the time.
4 Over 80% of the causes of crossing collisions and collisions while turning right are a delay
in noticing the motorcycle.
* Nearly 70% of the causes of this delay are an insufficient check on the traffic.
5 Crossing collisions occur more frequently during daytime hours, and collisions whileturning right during nighttime hours.
6 Mopeds are more frequently involved in crossing collisions, and small- and mini-sized
motorcycles in crossing collisions and collisions while turning right.

91

No.

発 行 （財）交通事故総合分析センター
発行月 平成 年 月 〒102 0083 東京都千代田区麹町6 6 麹町東急ビル 階

7 Motorcycle “daytime running lamps” can reduce crossing collisions.

2011

NOVEMBER

23

Precautions for motorcycle riders:(1) Motorcycles are known to beoverlooked more easily than cars.
Riders must always pay attention
to safe driving near the entrance ofparking lots or intersections, on theassumption of being overlooked bycars.
(2) Turn on the headlamps in thedaytime.

Precautions for car drivers:(1) Always try to stop before turning
right and be sure to check forvehicles in the opposite lane. Also
pay attention to a motorcycle thatmight come out from behind a car
or from the shoulder of the road.
(2) Always try to stop near theentrance of a parking lot orintersection and be sure to checkthe safety of the area. Drivers can
notice motorcycles, despite their
low conspicuity, by stopping the
car and carefully checking thetraffic.

事務局〒102-0083 東京都千代田区麹町6-6 麹町東急ビル5階
TEL03-3515-2525 FAX03-3515-2519

つくば交通事故調査事務所〒305-0831 茨城県つくば市西大橋6 41-1
（財）日本自動車研究所内
TEL029-855-9021 FAX029-855-9131

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