BGS
6. Praxiskonferenz
Fußgängerschutz
Analyse des Unfallgeschehens zwischen
PKW und Fahrrädern im Hinblick auf
passive Schutzmaßnahmen
Dipl.-Ing. Henrik LiersVerkehrsunfallforschung an der TU Dresden GmbH
6. Praxiskonferenz
Fußgängerschutz
2 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Overview
Motivation
Accident scenario involving cyclists
Descriptive statistics of cyclist accidents in GIDAS
Injury causation of cyclists
Use and protection potential of cycle helmets
Conclusions
6. Praxiskonferenz
Fußgängerschutz
3 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Decreasing trend in fatalities both for pedestrians and cyclists
However, it seems
that efforts in the
field of pedestrian
safety have been
more effective in the
last decade (based
on the decrease of
fatalities)
Germany: Converging
numbers of pedestrian
and cyclist fatalities
Motivation
overall fatalities in Germany (2009): 4.152
6. Praxiskonferenz
Fußgängerschutz
4 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Motivation
Similarities between pedestrian and cyclist accidents:
• similar relevance within accident scenario
• comparable conflict situations / accident types
• similar impact kinematics (esp. in frontal collisions)
Differences:
• single accidents of cyclists
• use of helmets
• own velocity of the cyclist (much higher than the pedestrian ones)
• presence of a vehicle (influence of lighting, possible technical
deficiencies, braking behavior etc.)
6. Praxiskonferenz
Fußgängerschutz
5 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Cyclist accident scenario worldwide
Cyclist accidents claim for thousands of fatalities and millions of
slightly and seriously injured people worldwide
Especially in some Asian countries remarkable numbers of cyclist
fatalities can be found (official numbers are partially highly doubtful)
China: ≈ 9.200 fatalities Brazil: ≈ 1.600 fatalities
India: ≈ 4.500 fatalities Japan: ≈ 850 fatalities
Indonesia: ≈ 2.200 fatalities USA: ≈ 750 fatalities
In many countries an increase/stagnation of the VRU’s proportion in
fatalities may be expected due to the strong increase in motorization
source: WHO - GLOBAL STATUS REPORT ON ROAD SAFETY, 2009
6. Praxiskonferenz
Fußgängerschutz
6 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Cyclist accident scenario in Europe
Europe (2009): ca. 2.250 killed cyclists per year (≈ 6.700 pedestrians)
Most European countries: general decrease of cyclist fatalities over
the last years (but also stronger decrease of pedestrian fatalities)
NL: more (than twice as many) cyclist fatalities than pedestrian
fatalities (the only country in Europe)
In some other European countries (incl. Germany): similar numbers
of pedestrian and cyclist fatalities or at least converging curves
In few European countries: increasing fatality numbers
source: CARE (EU road accidents database)
6. Praxiskonferenz
Fußgängerschutz
7 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Cyclist accident scenario in Germany
Cyclist accidents: important role in the German accident scenario
Despite a large number of unreported cases (especially single
accidents with less severe injuries), cyclist accidents occur more
than twice as often as pedestrian accidents
On the one hand: less cyclist fatalities than pedestrian fatalities
On the other hand: overall socio-economic costs (personal damage*)
of cyclist accidents are 1,5 times higher than pedestrian accidents
Germany (2009) pedestrians cyclists factor
Accidents involving … 33.076 75.913 2,3
fatally injured persons 591 462 0,8
seriously injured persons 8.139 14.182 1,7slightly injured persons 23.508 61.153 2,6
*source: Socio-economic costs due to road traffic accidents in Germany, BASt, 2009
6. Praxiskonferenz
Fußgängerschutz
8 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Cyclist accident scenario in Germany
47% of cyclist fatalities
result from collisions
with passenger cars
(not only frontal impacts)
Every fourth fatally
injured cyclist dies in
a single accident
(no potential for any
passive safety measures
on vehicles)
Trucks still cause every
fifth cyclist fatality
source: DESTATIS, 2009, own calculation
6. Praxiskonferenz
Fußgängerschutz
9 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Aims of the study
Aims of the current study (on behalf of ACEA):
• Characterization / descriptive statistics of bicycle accidents
(focus on collisions with passenger cars, impacts on the front)
• Analyses on injury level
- injury severity
- affected body regions
- injury causation
- comparison of different AIS coding guides
• Analyses concerning the impact distribution
• Helmet use and estimation of the protective potential of helmets
6. Praxiskonferenz
Fußgängerschutz
10 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Dataset
Use of the GIDAS (German In-Depth Accident Study) database
Accidents investigated in Hanover and Dresden from 1999-2009
After weighting the data to the German national statistics, there are
2099 accidents available for the analysis
known MAIS & collision speed: 2526
reconstructed accidents involving injured cyclists: 4897
frontal impact on the M1/N1 vehicle: 2785
accidents/collisions with M1/N1 vehicles: 3411
100%
70%
57%
52%
6. Praxiskonferenz
Fußgängerschutz
11 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Collision speed (= speed of the car) vs. injury severity of the cyclist
• 1934 accidents w/ collision speeds ≤40 kph: 1,4 fatalities (0,07%)
• 165 accidents w/ collision speeds >40 kph: 6,7 fatalities (4,09%)
Descriptive statistics of bicycle accidents in GIDAS
2099 accidents
≤ 40 kph:
1934 accidents (92,1%)
> 40 kph:
165 accidents (7,9%)
injury severity
of the cyclists
6. Praxiskonferenz
Fußgängerschutz
12 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Injury severity (MAIS) of the cyclists:
• 4 out of 5 injured cyclists are MAIS1 injured
• proportion of MAIS2+ / MAIS3+ injured cyclists: 19,2% / 3,2%
66,9 MAIS3+ injured cyclists
(3,2%)
AIS1990 Rev. 1998
403,1 MAIS2+ injured cyclists
(19,2%)
6. Praxiskonferenz
Fußgängerschutz
13 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Target of most efforts in vehicle/road safety are seriously/fatally
respectively MAIS2+ injured persons
The present study also focuses on the 403,1 accidents with
MAIS2+ injured cyclists
• 134,7 slightly injured cyclists (hospitalisation < 24 hours)
• 260,3 seriously injured cyclists (hospitalisation > 24 hours)
• 8,1 fatally injured cyclists (died within 30 days after accident)
High numbers of slightly injured cyclists (according to the official
definition) with an MAIS2+ result from the use of the AIS1990
Revision 1998
6. Praxiskonferenz
Fußgängerschutz
14 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
The vast majority of accidents between passenger cars and bicycles
(resulting in MAIS2+ injured cyclists) occur in urban areas
One fifth of the accidents happen during twilight or at night
6. Praxiskonferenz
Fußgängerschutz
15 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Crossings and T-junctions are the main accident locations of MAIS2+
injured cyclists, followed by straights
In every second accident no cycle way was available
Descriptive statistics of bicycle accidents in GIDAS
6. Praxiskonferenz
Fußgängerschutz
16 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
More than 80% of the cyclists have turning or crossing accidents
6. Praxiskonferenz
Fußgängerschutz
17 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
The main type of accident (describing the general type of conflict)
again shows the large importance of crossing situations
6. Praxiskonferenz
Fußgängerschutz
18 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
The most frequent accident types are crossing and turning situations
The majority of the initial situations are comparable to the
critical situations in frontal pedestrian accidents:
either perpendicular movement of the vehicles
or collision during turning
6. Praxiskonferenz
Fußgängerschutz
19 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Accident causation (main accident causes):
• The majority (62%) of the accidents are caused by the car
• “Ignoring the traffic sign ruling the right of way” is by far the most
frequent accident cause for both cars and bicycles
Contributing factors: • 4,4% of cases w/ intoxicated cyclist (alcohol)
• 7,8% of cases w/ technical deficiencies (cycle)
TOP5 of the main accident causes
Main accident causer = passenger car Main accident causer = bicycle
ignoring the traffic sign
ruling the right of way 46%
ignoring the traffic sign
ruling the right of way 34%
mistake during turning 20% mistake during the start in the traffic 14%
other mistakes of the driver 5% ignoring traffic lights (or police officer) 12%
mistake during the start in the traffic 5% use of the wrong (side of) road 10%
ignoring traffic lights (or police officer) 4% mistake during turning 9%
6. Praxiskonferenz
Fußgängerschutz
20 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Contrary to pedestrians bicycles have own velocities that can not be
disregarded (e.g. collision with standing passenger cars)
• Ø collision speed
(passenger car):
26,8 kph
(median 23 kph)
• Ø collision speed
(bicycle):
14,1 kph
(median 15kph)
6. Praxiskonferenz
Fußgängerschutz
21 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Personal data (MAIS2+ injured cyclists) – Gender & Age
• gender distribution: 58% male, 42% female
• contrary to pedestrians, the age of cyclists is more evenly
distributed (but less children up to 10 years)
age of the cyclists (grouped, in years)
6. Praxiskonferenz
Fußgängerschutz
22 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Personal data (MAIS2+ injured cyclists) – Body height
• remarkable proportions are only found above 150cm with an
average of 170,4cm
body height of the cyclists(grouped, in cm)
6. Praxiskonferenz
Fußgängerschutz
23 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Descriptive statistics of bicycle accidents in GIDAS
Injury data – Injury severity (AIS)
• in total, all MAIS2+ injured cyclists suffered 1749 single injuries
• most of their injuries are slight injuries (AIS1)
AIS1990 Rev. 1998
6. Praxiskonferenz
Fußgängerschutz
24 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Injury data – Affected body regions
Descriptive statistics of bicycle accidents in GIDAS
AIS 1+
n = 1749,3
AIS 2+
n = 684,9
AIS 3+
n = 147,5
6. Praxiskonferenz
Fußgängerschutz
25 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Injury data – Affected body regions
• all (AIS1+) injuries: lower extremities with largest proportion,
followed by upper extremities
• with increasing injury severity levels (AIS2+ AIS3+):
- the head is by far the most frequently injured body region
- the relevance of thorax increases substantially
- the portion of injuries on lower extremities remains nearly constant
- injuries on upper extremities and the face become less important
(there are hardly any AIS3+ injuries in these regions)
Descriptive statistics of bicycle accidents in GIDAS
6. Praxiskonferenz
Fußgängerschutz
26 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Detailed investigations on the causation of injuries is a substantial
part of in-depth accident studies like GIDAS
The injury causing part is coded for every single injury (70.000 so far)
Various analyses on injury causation can be done, e.g.:
• estimation of the relevance of several vehicle parts
• influence of the secondary / ground impact
• observation of the development of particular injury causing parts
against the background of ongoing efforts in road/vehicle safety
Here: Analysis of injury causation for the three most relevant body
regions of cyclists (head/face, thorax, lower extremities)
Injury causation of cyclists
6. Praxiskonferenz
Fußgängerschutz
27 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
head/face injuries AIS1+
window frame / A-pillar 43,3
windscreen 131,5
bonnet 12,2
bonnet leading edge 0,5
fender 3,9
grill and headlamps --
bumper --
other veh. parts / front nfs. * 23,4
own bicycle / other / unknown ** 10,4
ground impact 378,9
total 604,1
head/face injuries AIS1+ AIS2+
window frame / A-pillar 43,3 28,9
windscreen 131,5 74,4
bonnet 12,2 6,6
bonnet leading edge 0,5 0,5
fender 3,9 1,6
grill and headlamps -- --
bumper -- --
other veh. parts / front nfs. * 23,4 9,5
own bicycle / other / unknown ** 10,4 0,5
ground impact 378,9 159,9
total 604,1 281,9
head/face injuries AIS1+ AIS2+ AIS3+
window frame / A-pillar 43,3 28,9 15,8
windscreen 131,5 74,4 21,9
bonnet 12,2 6,6 --
bonnet leading edge 0,5 0,5 --
fender 3,9 1,6 --
grill and headlamps -- -- --
bumper -- -- --
other veh. parts / front nfs. * 23,4 9,5 2,9
own bicycle / other / unknown ** 10,4 0,5 --
ground impact 378,9 159,9 25,0
total 604,1 281,9 65,6
Injury causing parts of head/face injuries
• with increasing injury severity (AIS1+ AIS2+ AIS3+):
- window frame & windscreen more important, BLE not relevant
- ground impact very important with decreasing proportions
Injury causation of cyclists
* incl. mirrors, B-pillar, doors, wheels, roof, glass etc.
** incl. body motion, all parts of the bicycle etc.
6. Praxiskonferenz
Fußgängerschutz
28 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
injuries on lower extremities AIS1+
window frame / A-pillar 1,4
windscreen 6,5
bonnet 22,7
bonnet leading edge 25,8
fender 27,0
grill and headlamps 8,1
bumper 118,3
other veh. parts / front nfs. * 34,8
own bicycle / other / unknown ** 38,5
ground impact 210,1
total 493,1
Injury causing parts of injuries on lower extremities (incl. pelvis)
• mainly caused by the bumper (often the first contact point
between cyclist and car)
• relevance of the ground decreases slightly for higher AIS values
Injury causation of cyclists
* incl. mirrors, B-pillar, doors, wheels, roof, glass etc.
** incl. body motion, all parts of the bicycle etc.
injuries on lower extremities AIS1+ AIS2+
window frame / A-pillar 1,4 0,5
windscreen 6,5 1,7
bonnet 22,7 5,9
bonnet leading edge 25,8 9,8
fender 27,0 8,6
grill and headlamps 8,1 3,9
bumper 118,3 70,7
other veh. parts / front nfs. * 34,8 12,1
own bicycle / other / unknown ** 38,5 10,7
ground impact 210,1 49,8
total 493,1 173,8
injuries on lower extremities AIS1+ AIS2+ AIS3+
window frame / A-pillar 1,4 0,5 --
windscreen 6,5 1,7 --
bonnet 22,7 5,9 1,1
bonnet leading edge 25,8 9,8 3,7
fender 27,0 8,6 0,9
grill and headlamps 8,1 3,9 0,5
bumper 118,3 70,7 14,1
other veh. parts / front nfs. * 34,8 12,1 3,1
own bicycle / other / unknown ** 38,5 10,7 --
ground impact 210,1 49,8 7,9
total 493,1 173,8 31,3
6. Praxiskonferenz
Fußgängerschutz
29 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
thorax injuries AIS1+
window frame / A-pillar 8,8
windscreen 20,1
bonnet 24,2
bonnet leading edge 4,1
fender 2,9
grill and headlamps --
bumper --
other veh. parts / front nfs. * 5,7
own bicycle / other / unknown ** 6,5
ground impact 40,6
total 112,9
thorax injuries AIS1+ AIS2+
window frame / A-pillar 8,8 6,4
windscreen 20,1 10,3
bonnet 24,2 8,6
bonnet leading edge 4,1 4,1
fender 2,9 1,5
grill and headlamps -- --
bumper -- --
other veh. parts / front nfs. * 5,7 2,1
own bicycle / other / unknown ** 6,5 --
ground impact 40,6 12,1
total 112,9 45,1
Injury causing parts of thorax injuries
• mainly caused by the ground impact, followed by the windscreen,
window frame and the bonnet
• the BLE looses its relevance for AIS3+ thorax injuries
Injury causation of cyclists
* incl. mirrors, B-pillar, doors, wheels, roof, glass etc.
** incl. body motion, all parts of the bicycle etc.
thorax injuries AIS1+ AIS2+ AIS3+
window frame / A-pillar 8,8 6,4 3,3
windscreen 20,1 10,3 7,4
bonnet 24,2 8,6 5,4
bonnet leading edge 4,1 4,1 0,6
fender 2,9 1,5 1,5
grill and headlamps -- -- --
bumper -- -- --
other veh. parts / front nfs. * 5,7 2,1 1,6
own bicycle / other / unknown ** 6,5 -- --
ground impact 40,6 12,1 9,0
total 112,9 45,1 28,8
6. Praxiskonferenz
Fußgängerschutz
30 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Analysis of the helmet usage of all cyclists in GIDAS
• generally: low helmet usage rates (slowly increasing over time)
• comparable rates in GIDAS (only accidents with injuries) and
normal traffic situations (e.g. BASt helmet use surveys)
Analyses on cycle helmets
6. Praxiskonferenz
Fußgängerschutz
31 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Analysis of the helmet usage of all cyclists in GIDAS
• helmet usage rate differs substantially with the cyclist’s age
Analyses on cycle helmets
average = 9,1%
6. Praxiskonferenz
Fußgängerschutz
32 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Analysis of the helmet usage of all cyclists in GIDAS
• gender distribution (all age groups, n = 5.296)
- male: 11,5%
- female: 5,2%
• gender distribution (≥ 16 years, n = 4.481 )
- male: 10,5%
- female: 3,7%
• gender distribution (≥ 50 years, n = 1.587)
- male: 8,4%
- female: 1,7%
Analyses on cycle helmets
6. Praxiskonferenz
Fußgängerschutz
33 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Estimation of the protective potential of cycle helmets
1st step: Comparison of cyclist accidents with and without helmet use
(to ensure that the general accident scenarios are comparable)
• Cyclists wearing helmets are appr. 8 years younger on average
• Cyclists with helmets are approximately 3 kph faster on average
• The collision speeds of the cars are similar
Accident situations w/ and w/o helmets are pretty comparable
Analyses on cycle helmets
average …accidents with
helmet use (n=171,5) no helmet use (n=1756,0)
… collision speed (car) 19,2 kph 20,1 kph
… collision speed (bicycle) 16,3 kph 13,5 kph
… cyclist age 30,7 yrs 38,4 yrs
6. Praxiskonferenz
Fußgängerschutz
34 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Expected benefit of helmets especially for the head Comparison of
the injury severity of the AIS region head (all cyclists in GIDAS)
• remarkable changes
of the injury severity
• no AIS4+ injuries are
found in accidents
with helmets
- AIS4: -0,54%
- AIS5: -0,17%
- AIS6: -0,05%
• proportion of cyclists
without head injuries
increases by 10,8%
Analyses on cycle helmets
6. Praxiskonferenz
Fußgängerschutz
35 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Conclusions I
Cyclists play an important role in traffic accidents worldwide
Germany: cyclist fatalities converge to pedestrian fatalities; higher
numbers of slightly and seriously injured cyclists than pedestrians
Accidents with passenger cars are the main reasons for cyclist
fatalities (47%) in Germany, followed by single accidents (23%)
Due to higher own velocities and occurrence of single accidents:
“ground line” of cyclist casualties not addressable (by vehicle safety)
80% of collisions with passenger cars are frontal impacts
More than 90% of these accidents happen at collision speeds ≤ 40 kph
Every 5th cyclist at least MAIS2+ injured, every 30th MAIS3+ injured
6. Praxiskonferenz
Fußgängerschutz
36 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Conclusions II
In general, severe cyclist accidents (MAIS2+) in GIDAS occurred:
• in urban areas
• during daytime
• in crossing / turning situations
• at crossings and junction
Approximately two thirds of frontal car-to-cycle accidents are caused
by the passenger car and mostly due to the violation of right of way
There are typical injury causing parts for every body region:
• head/face: windscreen, window frame, ground impact
• thorax: windscreen, bonnet, ground impact
• lower extremities: bumper, ground impact
6. Praxiskonferenz
Fußgängerschutz
37 BGS© 2011 carhs.training gmbh / BGS Böhme & Gehring GmbH
Conclusions III
The head is the most frequently injured body region of MAIS2+
injured cyclists, followed by the lower extremities and the thorax
The ground impact plays an important role (especially in single
accidents and in collisions with (nearly) standing passenger cars)
The use of cycle helmets is still not very usual in Germany
Helmet usage rates strongly depend on the age and the gender
Using a helmet can both protect the head from suffering very severe
injuries and increase the number of cyclists without head injuries
Out of the study’s results, it is recommended to enforce:
• helmet use • prevention measures
• driving abilities • primary & secondary safety measures