Analyzing human factors in road accidents: TRACE WP5 Summary Report

The main objectives of TRACE WP5 'Human factors' deliverables are: i) To support a better standardization of accident analysis in Europe on a scientific background, ii) To provide operational models and methodological classification grids dealing with 'human factors' aspects involved in road accidents, iii) To promote a comprehensive analysis of the involvement of human beings, going further than the usual 'user-orientated causal analysis' often limited at establishing the driver 'at fault' and without searching for the background reasons of the problems met par road users. Such objectives involve analyzing accidents as the symptom of the difficulties met by drivers in certain driving situations, and as a revelatory of their needs in help. Two questions have to be asked in order to progress in the understanding of accident causation: 1) What are precisely and operationally the human failures in accidents? But also: 2) What are the reasons for these human failures? Keeping in mind that these reasons are of multiple natures and combine most of the time to produce the final event. By so doing, the definition of typical scenarios of 'human error' production can open to the definition of more appropriate countermeasures, well fitted to human needs

Which factors and situations for human functional failures? Developing grids for accident causation analysis

This report describes the work undertaken in Task 5.2 of the TRACE project. Human failures are explained by factors characterizing the state of the system and of their interactions. A grid of factors which could lead to these human functional failures is given along with a grid of pre-accident driving situations. In addition to this, an overview is included of the background work undertaken to establish a methodology for classification of these factors and situations. Factors related to the ‘User’, ‘Vehicle’ and ‘Environment’ are described and classifications for use at a ‘descriptive’, ‘generic’ and ‘in-depth’ level are determined, to allow analysis at different levels of detail of accident data. These factors and situations will be used along with the Task 5.1 functional failures to help identify typical failure generating scenarios in Task 5.3, and the subsequent analysis of real world accident data in other work packages in TRACE. They will also be a useful basis for future improvements in the collection of accident causation data, avoiding the common over simplification whereby road users are seen as the main reason for the ‘failure’ in the accident scenario

An analysis of speed related UK accidents using a human functional failure methodology

Accidents involving either illegal or inappropriate speeding play a part in a large proportion of accidents involving cars. The types of typical failure generating scenarios found in car accidents where illegal speeding or inappropriate speeding is contributory are compared using the detailed human functional failure methodology developed in the European TRACE project (TRaffic Accident Causation in Europe), funded by the European Commission. Using on-scene cases from the UK ‘On The Spot’ database (funded by the UK Department for Transport and Highways Agency), a sample of cases where speed is contributory have been analysed. An overview of speeding cases from the 4,000 in-depth cases available in the dataset is also presented. The results highlight not only the differences between inappropriate and illegal speeding cases, but also the differences in the functional failures experienced by both the ‘at fault’ and ‘not at fault’ road users in both types of speed-related accidents. The results form a unique base of knowledge for future work on the human-related issues associated with speeding of both types, for all crash participants. Also considered is how new technologies can address speeding accidents

Accident causation and pre-accidental driving situations: Part 1. Overview and general statistics

WP2 of the European Project TRACE is concerned with “Types of Situations” to analyse the causation of road traffic accidents from the pre-accidental driving situation point of view. Four complementary situations were defined: stabilized situations, intersection, specific manoeuvre and degradation scenario. To reach this objective, the analysis is based on a common methodology composed on 3 steps: the “descriptive analysis” which from general statistics will allow to identify among the studied situations those them relevant and to give their characteristics, the “in-depth analysis” allowing to obtain accident causes from the generic description of the problems identified in the previous step and the risk analysis identifying the risk of being involved in an accident taking into account the results obtained from the ‘in–depth’ level. This report is dedicated to the descriptive analysis with the identification of the most relevant scenario regarding the situation in which the driver is involved just prior the accident. The results are based on the literature review, general statistics and the analysis of the national databases available in TRACE via WP8. Because the information level differ from databases to another, the available scenario presented here for the 4 predefined types of situations are generics and some specific situations could not have be distinguished. For each situation some key indicators are given, such as prevalence, severity, KSI (killed x severely injured), etc. When it is possible, these indicators are estimated at the EU27 level

Single-vehicle collisions in Europe: analysis using real-world and crash-test data

A large proportion of European road casualties result when a vehicle leaves the main carriageway, often impacting roadside obstacles. As part of the EC-funded project, RISER (Roadside Infrastructure for Safer European Roads), a number of activities were undertaken to collate the type of data which is needed to understand the frequency and severity of real world crash situations and relate this to crash test data mandated in the EU. Accident data was collected and used to create a statistical database and a detailed database exclusively for single vehicle 'run-off the road' collisions on major rural (not urban) roads, simulation software was used to further understand impacts with roadside structures and an inventory of crash test data was collected for impacts with objects such as poles and safety barriers . The combination of real world accident data, simulations and crash test data has provided a unique insight into the characteristics of single vehicle collisions, helping us to understand them better and make recommendations for consideration when drafting design guidelines. This information is crucial for those involved in the design and evaluation of the roadside environment

Accident causation and pre-accidental driving situations. Part 3. Summary report

This report aims to present the final results of the descriptive statistical, in-depth and risk analysis performed within TRACE Work Package ‘WP2-Type of situations’, in order to identify the main problems and the magnitude of these problems related to accident causation and risk factors for the following four types of situations: the stabilized situations, the specific manoeuvres, the intersection situations and the degraded situations. The different analysis (descriptive, in-depth and risk) of each of these five tasks has been performed using the available European accident databases within TRACE (national, in-depth and exposure databases). The objectives achieved in this WP are: • Identify and quantify accident causation factors associated to particular types of driving and pre-accidental situations, at a statistical level, by analyzing various available databases in Europe. • Obtain a focused understanding of accident causation issues related to these types of situations at an in-depth level by analyzing data from available in-depth databases. • Identify the level of risk associated to these selected types of situation in causing accidents

Accident causation and pre-accidental driving situations. Part 2. In-depth accident causation analysis

WP2 of the European Project TRACE is concerned with “Types of Situations” to analyse the causation of road traffic accidents from the pre-accidental driving situation point of view. Four complementary situations were defined: stabilized situations, intersection, specific manoeuvre and degradation scenario. To reach this objective, the analysis is based on a common methodology composed on 3 steps: the “descriptive analysis” which from general statistics will allow to identify among the studied situations those them relevant and to give their characteristics, the “in-depth analysis” allowing to obtain accident causes from the generic description of the problems identified in the previous step and the risk analysis identifying the risk of being involved in an accident taking into account the results obtained from the ‘in–depth’ level. This report is dedicated to the identification of the accident causes analysed for the pre-accidental driving situation point of view, i.e. the circumstances in which the driver is involved just prior the accident. This analysis has been conducted from the scenarios identified for each type of situation during the descriptive analysis realized in a first part (Report D2.1: Accident causation and pre-accidental driving situations. Part 1. Overview and general statistics). These results are based on the study of disaggregated data (in-depth accidents collection databases) available via WP8 in TRACE. With the identification of the main causes and contributing factor, the aspect related to the human functional failure has been taken into account. This innovative concept studied in TRACE WP5, has been used here in order to have a more complete overview of the problems in working on each road users involved in the accident and not only on the whole accident

Trip related factors

WP3 of the European Project TRACE is concerned with Types of Factors to analyse the causation of road traffic accidents from a factors' point of view. In task 3.3 'Trip-related Factors' it was tried to characterise accidents that are caused by certain contributing factors found on a trip level. This was done by applying one statistical method to existing databases of the WP3 Partners on the one hand and on the other hand by performing an in-depth case analysis using the WP5 method. The analysed factors stem from the Human Component of the accident causation classification, namely "alcohol", "vigilance", and "experience", from the Vehicle Component, namely "vehicle condition/maintenance", and from the Environment component, namely "road layout" and "road condition". This selection resulted from the task 3.1 conclusions and feasibility reasons. Due to inhomogeneous results for the databases from Austria, France, Germany, Great Britain, and Spain the detailed results will be pictured in an Internal TRACE Report by Sub-reports of the WP3 Partners, in this task report the main results are discussed with respect to findings and data in other databases available to the TRACE partners as requested from WP8. Both methods applied show that trip-related factors are possible to prevent not on a trip level only, but also from a background level and as well on a level closer to the accident (driving task level). However, only some suggestions are possible to give by these results. A more detailed view for preventing the different accidents that result from trip-related factors is necessary, as shown by the results of BASt with the statistic method, as well as by INRETS with the ultra in-depth WP5 method

Summary report on work package 3 "Types of Factors"

This summary report presents the main results of Work Package 3 "Types of Factors" of the TRACE Project. The work as performed in the tasks 3.1 (accident related factors), 3.2 (sociological and cultural factors), 3.3 (trip-related factors), and 3.4 (driving-task associated factors) and presented in the Deliverables 3.1 to 3.4 and an additional internal TRACE Report (Collection of Sub-Reports for task 3.3) is summarized and discussed. The objective of defining relevant accident related factors first and the objective of analysing traffic accident causation - from a factor's point of view while taking traditional views into account - on different levels - by using statistic methods for existing databases as provided by the Work Package 3 Partners and - by using new (developed in Work Package 5 of the TRACE project) methods on new case analysis in order to gain new knowledge on accident causation was possible to reach. The scope of the identified key aspects as found by the Partners in their work for the relevance in EU27 is discussed. In accordance, even further, appropriate suggestions for prevention of traffic accidents can be derived

Driving task-related factors

Driving task-related factors by definition are ‘directly and causally contributing to the accident occurrence, very specific and detailed, are short-term lasting or dynamic in nature, and refer to the actual conditions of the components’. The aim was to analyse specific driving task-related factors to investigate how these type of factors affect the driver undertaking their tasks within driving. A selection of driving task-related factors were chosen and analysed using two types of analysis; by a statistical method and by an in-depth methodology developed in TRACE. Typical characteristics of these accidents were identified, and for a number of factors, typical failure generating scenarios were also identified. From this, a list of possible countermeasures were defined with the aim of preventing such accidents occurring. These included driver education, in-vehicle technologies and design issues. Finally, benefits and limitations of the analysis undertaken are given, with recommendation for future work on driving task-related factors