In-depth accident causation database and analysis report

186 Pages·2008·15.15 MB·English

Deliverable 5.8: In-depth accident
causation database and analysis report

Contract No: TREN-04-FP6TR-SI2.395465/506723
Acronym: SafetyNet
Title: Building the European Road Safety Observatory

Integrated Project, Thematic Priority 6.2 “Sustainable Surface
Transport”

Project Co-ordinator:
Professor Pete Thomas
Vehicle Safety Research Centre
Ergonomics and Safety Research Institute
Loughborough University
Holywell Building
Holywell Way
Loughborough
LE11 3UZ

Organisation name of lead contractor for this deliverable:
Chalmers University of Technology

Due Date of Deliverable: 30 October 2008

Submission Date: 04 December 2008

Report Author(s): K. Björkman, H. Fagerlind, M. Ljung Aust, E. Liljegren
(Chalmers); A. Morris, R. Talbot, R. Danton (VSRC); G. Giustiniani,
D. Shingo Usami (DITS); K. Parkkari (VALT); M. Jaensch (MUH);
E. Verschragen (TNO)

Project Start Date: 1st May 2004 Duration: 4, 5 years

Project co-funded by the European Commission within the Sixth Framework Programme (2002 -2006)
Dissemination Level
PU Public (cid:57)
PP Restricted to other programme participants (inc. Commission Services)
RE Restricted to group specified by consortium (inc. Commission Services)
CO Confidential only for members of the consortium (inc. Commission Services)

Project co-financed by the European Commission, Directorate-General Transport and Energy

D 5.8: In-depth accident causation database and analysis report
Executive Summary
The SafetyNet project is an Integrated Project (IP) which was developed as part of
the European Commission’s 6th Framework programme. SafetyNet has built the
foundations of a European Road Safety Observatory (ERSO) which can be used by
the European Commission for the purposes of policy review and development. The
SafetyNet project is divided into seven main Work Packages each of which deal with
specific aspects of road safety research (see www.erso.eu).
The objective of the SafetyNet Work Package 5, Task 2 was to develop an in-depth
European accident causation database to identify risk factors that contribute to road
accidents. To assist in the analysis of the accident causation a method, known as
SNACS, was further developed, tested and revised throughout the project. The
accident investigations were performed by existing multidisciplinary teams within the
partnership which have many years of experience.
The accident causation database was developed in two parts; a set of general
variables about the accident, vehicle, road environment and road users and a part
which was dedicated to the accident causation analysis performed with the SafetyNet
Accident Causation System (SNACS). The definitions for the general variables and
values as well as the SNACS method were piloted and revised several times before
data collection commenced to ensure high quality in the gathered data.
In total, 1006 accident cases were investigated which include 1833 vehicles and
pedestrians. In the aggregated analysis these vehicles were grouped according to
their trajectory prior to the accident and the groups were; Vehicles leaving their lane
(n = 354), Vehicles encountering something in their lane (n = 537), Vehicles
encountering another vehicle on crossing paths (n = 528) and Accidents involving
slower moving vulnerable road users (n = 92 pedestrians; 95 Pedal Cyclists, 177
opponents)
The aim of the analyses conducted was not to explore and evaluate the effectiveness
of new technologies, but rather to demonstrate the potential uses for the accident
causation database and identify common accident scenarios. The SNACS charts in
the groups were aggregated to allow the most commonly occurring accident
contributing factors to be identified. In the SNACS charts the information is rich and
detailed and it is by nature complex as it reflects the complex interactions between
the road users, vehicles and environment that occur in an accident. The SNACS
method assists in the process of identifying patterns that will allow the most common
accident contributing factors to be focused on when designing countermeasures.

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D 5.8: In-depth accident causation database and analysis report
Abbreviations and definitions
Abbreviations
ACASS Accident Causation Analysis with Seven Steps
ERSO European Road Safety Observatory
CARE Community database on Accidents on the Roads in Europe
Chalmers Chalmers University of Technology, Sweden
DITS Department ‘Idraulica Transporti Strade’ at University of Rome “La
Sapienza”, Italy
DREAM Driving Reliability and Error Analysis Method
FR In section 3.2 Striking vehicle in front
GDV German Insurance Industry
GIDAS German in-Depth-Accident Study
LTAP-LD Left Turn Across Path-Lateral Direction
LTAP-OD Left Turn Across Path-Opposite Direction
LTIP Left Turn Into Path
MUH Medical University of Hannover, Germany
O In section 3.2 Striking object other than vehicle in front
OTS On-The-Spot accident research
RF In section 3.2 Being struck from behind
RTIP Right Turn Into Path
S In section 3.2, Being struck by a vehicle which has left its lane
SCP Straight Crossing Paths
SNACS SafetyNet Accident Causation System
SVRU Slower Moving Vulnerable Road Users
TNO Netherlands Organisation for Applied Scientific Research, The
Netherlands
VALT Finnish Motor Insurers' Centre, Finland
VSRC Vehicle Safety Research Centre, United Kingdom

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D 5.8: In-depth accident causation database and analysis report
Definitions
Accident investigation Acquisition of factual information regarding an accident (note: can
include on-scene elements, elements recorded retrospectively, or
both of these) [ISO 12353-1:2002].
SafetyNet comment: It includes both “data collection” and “case
analysis”.
Accident notification A message from the emergency service is sent to the on-scene
team when an accident occurred.
Accident scene The area of a traffic accident before the vehicles and people
involved have left [ISO 12353-1:2002].
Accident site The geographic location of the accident scene (note: the accident
site may be given as exact coordinates or in a less detailed way)
[ISO 12353-1:2002].
Case A case is a separate accident that has been chosen for accident
investigation. Each accident investigation is treated as a case.
Case analysis The analysis of one specific accident using the data collected,
performed by investigators.
Data analysis Aggregate analysis of all or selected cases in the database.
Data collection Objective data collected on-scene, retrospectively or data retrieved
from other sources. Data collection also includes subjective
information, such as interviews.
Investigation team A multidisciplinary group of investigators investigating a specific
accident.
Investigator A person with expert knowledge in one or more areas of accident
investigation
On-scene (accident) Accident investigation conducted at the accident scene with the
investigation purpose of collecting on-scene information before physical evidence
(e.g. the vehicles involved) has been removed [ISO 12353-1:2002].
On-scene team A team of investigators who are ready to respond to an accident
notification and perform on-scene investigations.
Retrospective A complete accident investigation conducted retrospectively, i.e. no
(accident) on-scene investigation is conducted.
investigation
Retrospective When an on-scene accident investigation has been conducted,
inspection retrospective inspections of vehicles is conducted.
Retrospective team A team of investigators who are performing retrospective
investigations or retrospective inspections.
Sampling criteria Principals of evaluation of scope and coverage of an accident
investigation referring to different aspects [ISO 12353-1:2002].

The terms and definitions taken from ISO 12353-1:2002 Road Vehicles - Traffic accident
analyses, Part 1: Vocabulary, are reproduced with permission of the International
Organization for Standardization, ISO. This standard can be obtained from any ISO member
and from the Web site of ISO Central Secretariat at the following address: www.iso.org.
Copyright remains with ISO."

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D 5.8: In-depth accident causation database and analysis report
Table of Content
Executive Summary ..................................................................................................... I
Abbreviations and definitions ...................................................................................... II
Abbreviations .......................................................................................................... II
Definitions .............................................................................................................. III
Table of Content ........................................................................................................ IV
1 Introduction .......................................................................................................... 1
1.1 Background ................................................................................................... 1
1.2 Objectives of SafetyNet Accident Causation Database ................................. 2
1.3 Partners involved ........................................................................................... 2
2 Accident investigation methods ........................................................................... 3
2.1 Overview of the database .............................................................................. 3
2.2 Data collection ............................................................................................... 5
2.2.1 Germany (MUH) ...................................................................................... 6
2.2.2 Italy (DITS) .............................................................................................. 8
2.2.3 The Netherlands (TNO) .......................................................................... 9
2.2.4 Finland (VALT) ...................................................................................... 11
2.2.5 Sweden (Chalmers) .............................................................................. 12
2.2.6 UK (VSRC) ............................................................................................ 13
2.2.7 Summary .............................................................................................. 15
2.3 Introduction to SNACS - SafetyNet Accident Causation System ................. 16
3 Aggregated SNACS-data analysis .................................................................... 19
3.1 Vehicle leaving its lane ................................................................................ 22
3.1.1 Sorting .................................................................................................. 24
3.1.2 Analysis and results .............................................................................. 24
3.1.3 Discussion and conclusions .................................................................. 40
3.2 Vehicle encountering something in its lane, either in front or from the rear . 41
3.2.1 Sorting .................................................................................................. 42
3.2.2 Analysis ................................................................................................ 43
3.2.3 Results .................................................................................................. 44
3.2.4 Discussion and conclusions .................................................................. 60
3.3 Vehicle encountering another vehicle on crossing paths ............................. 63
3.3.1 Sorting .................................................................................................. 65
3.3.2 Analysis ................................................................................................ 66
3.3.3 Results .................................................................................................. 67
3.3.4 Discussion............................................................................................. 83
3.3.5 Conclusions .......................................................................................... 86
3.4 Accidents involving vulnerable road users ................................................... 86
3.4.1 Sorting .................................................................................................. 87
3.4.2 Analysis ................................................................................................ 87
3.4.3 Results .................................................................................................. 91
3.4.4 Discussion and conclusions ................................................................ 116

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3.5 Aggregated analysis summary .................................................................. 117
3.5.1 Vehicle leaving its lane ....................................................................... 117
3.5.2 Vehicle encountering something in its lane, either in front or from the rear
118
3.5.3 Vehicle encountering another vehicle on crossing paths .................... 119
3.5.4 Accidents involving Slower moving Vulnerable Road Users ............... 119
4 Small scale study comparing cases analysed with SNACS and ACASS
respectively ............................................................................................................. 121
4.1 Introduction to Accident Causation Analysis with Seven Steps – ACASS . 121
4.2 Comparing case analysed with SNACS and ACASS respectively............. 122
4.2.1 Data analysis of cases analysed with the ACASS method ................. 123
4.2.2 Data analysis of cases analysed with the SNACS method ................. 125
4.2.3 Discussion........................................................................................... 126
5 General discussion .......................................................................................... 127
6 Conclusions ..................................................................................................... 129
7 References ...................................................................................................... 130

Appendices
APPENDIX A: SNACS linking table with glossary for Phenotypes and Genotypes
APPENDIX B: How to sort the accidents
APPENDIX C: List of ACASS codes

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D 5.8: In-depth accident causation database and analysis report
1 Introduction
The SafetyNet project is an Integrated Project (IP) which was developed as part of
the European Commission’s 6th Framework programme. SafetyNet has built the
foundations of a European Road Safety Observatory (ERSO) which can be used by
the European Commission for the purposes of policy review and development. The
SafetyNet project is divided into seven main Work Packages each of which deal with
specific aspects of road safety research (ERSO, 2008).
This deliverable describes the second task of Work Package 5 of SafetyNet which
involves the development of a method for assessment of accident contributing factors
and an accident causation database including 1006 individual cases. The accidents
were investigated using an analysis approach known as the SafetyNet Accident
Causation System (SNACS) (Reed and Morris, 2008) to classify the contributing
factors that lead to the crash. The report briefly describes the methods used to collect
the data and the case analysis procedures. However, the emphasis of this report is
dedicated to the aggregation of cases and the outcome from the data analysis.
In addition to the accident investigation activities, a small scale comparative study
was performed between cases analysed with the developed method within SafetyNet
(SNACS) and the Accident Causation Analysis with Seven Steps (ACASS) method
used in investigations at the Medical University of Hanover (MUH).
1.1 Background
Fatalities and injuries due to traffic accidents are one of the major health problems in
the world today. About 10 million people get injured in traffic accidents every year
and the number will probably rise due to population growth and increase of mobility
(Peden et al., 2001)
The European Commission stated in the Road Safety Strategy that the number of
fatalities in the EU-25 member states should decrease by 50 percent by the year
2010 (European Communities, 2001). To meet this target there is a need for better
understanding of why accidents happen. One tool to enhance this knowledge is to
perform accident investigations by data collection from the accident scene and
interview involved road users. The data is then put together in a case analysis to find
contributing factors leading to the accident. It is interesting both to gain knowledge
about the performance of the in-vehicle technological systems aimed at accident
mitigation as well as the human behaviour in different road environments. Accident
data is needed both to assess the performance of existing systems but also as a
support in the development of future systems.

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D 5.8: In-depth accident causation database and analysis report
1.2 Objectives of SafetyNet Accident Causation Database
There were two main objectives for the SafetyNet Work Package 5, Task 2;
- to develop an in-depth European accident causation database to identify risk
factors that contribute to road accidents.
- to develop a method to assist the investigators in the analysis of the accident
for better understanding and categorising of accident contributing factors
The objectives of this report is to give an short overview of the methodology used for
accident investigation and to present selected results of the aggregation of data from
SafetyNet Accident causation Database.
1.3 Partners involved
Six partners were involved in the development of the accident causation database.
The partners represented six countries within the European Union and are
independent groups with no interest in commercial aspects of the study outcomes.
The partners were (Figure 1):

• Germany: Medical University of Hannover (MUH)
• Italy: Department ‘Idraulica Transporti Strade’ at University of Rome “La
Sapienza” (DITS)
• The Netherlands: Netherlands Organisation for Applied Scientific Research
(TNO)
• Finland: Finnish Motor Insurers' Centre (VALT)
• Sweden: Chalmers University of Technology (Chalmers)
• United Kingdom: Vehicle Safety Research Centre (VSRC)

Figure 1, Project teams

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D 5.8: In-depth accident causation database and analysis report
2 Accident investigation methods
The accident data collected within the project was collected by six separate teams
between 2005 and 2008. A combination of “on-scene” and “nearly on scene”
methods were used and multidisciplinary teams investigated the accidents following
accident notification by going on site and conducting vehicle- and road inspections as
well as interviews with the crash participants. The data collection method is described
in section 2.2.
The accident causation database was developed in two parts. A set of general
variables about the accident, vehicle, road environment and road users was
developed in conjunction with the Work Package 5.1 Fatal accident database and
these variables are common for both databases. The second part which is specific to
the accident causation database was the development of a European method for
recording accident causation information. The method developed was SNACS
(SafetyNet Accident Causation System), the development of which is documented in
section 2.3.
The definitions for the general variables and values as well as SNACS were piloted
and revised several times before data collection commenced to ensure high quality in
the gathered data. More detailed information about the pilot study can be found in
Paulsson and Fagerlind (2006).
2.1 Overview of the database
In total, the database contains 1006 cases, 1833 vehicles and 2428 road users. The
number of cases investigated by each team is presented in Table 1. Most of the
vehicles involved in the accidents are passenger cars (64%); the second largest
category is motorized two-wheelers (10%). The remaining vehicles are scattered over
the other categories and no category is larger than 7%. (Table 2)
Table 1, Contribution to the accident causation database by partner
SafetyNet Accident Causation Database
Participant ID Germany Italy The Finland Sweden UK Total
Netherlands
Cases 100 260 126 200 70 250 1006

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