Urban Road Safety How to deal with complexity? D. Fleury – INRETS Conference Physics and the City. Bologna 15-17 December 2005. Department of Accident Mechanisms (INRETS) Research in the field of Road Safety
How to deal with complexity?
D. Fleury – INRETS
Conference Physics and the City.
Bologna 15-17 December 2005
In Depth Accident Investigation (IDAI)
Études détaillées d’accidents (EDA)
Specific research issues based on system analysis
Man (driver-pedestrian) regulates the (M/V/R) system in real time
Macro-regulation and social management of safety
Regulation performed in “response” delay time, with the observation of user behaviour (driving speeds, accidents, perceived risks, opinions, etc.)
Accidents are the symptom of a dysfunctional situation in the interactions between components in the M/V/R system
Baker and Fricke (1986)
network and choice of
characteristics of the
carriageway and section
break related to a section
or particular location
(intersection, for example)
fine characteristics of the
Emergency and collision situations
Consistency (INRETS)(between the different levels) of the layout in question
Accident analysis, not restricted to immediate interaction, leading to actions for treating black spots as well as town planning and transportation policy.
A field of research: the notion of typical scenarios as “road pathologies"
Wide through road, problems of visibility (night, wetness, age, advertising, etc.)
High speed, low attention
Pedestrian preparing to cross outside a pedestrian crossing
View obstructed by a standing vehicle, the pedestrian crosses
No manoeuvre (surprise)
Example of research on accident scenarios : from IDAI (EDA) to intelligent safety diagnosis
1. Construction of “scenarios” on a panel of accidents
2. Scenarios recognition through police reports (and accident files)
Structure of the knowledge field
Symptoms (data) for recognition
3. Links between road environment and accident scenarios
Scenarios profiles (% of each scenario)
Systems with decision-making and memory centres (ref.: Boulding)
Models coming from psychology and safety diagnosis of large socio-technical systems
On the role of memorisation.
Rasmussen model (1980), level of cognitive operation: problem, procedural and automation resolution.
On decision-making and motivation.
To improve safety, we have to understand the Functional descriptions of the system and the regulation goals
Research example: descriptions of the system and the regulation goals
Urban Travel Plan design (Plans de Déplacements Urbains)
Law on the Air and Rational Energy Use – 1996
Law on Solidarity and Urban Renewal – 2000
Follow-up work meetings for nearly one and a half years
Design Process descriptions of the system and the regulation goals
The Urban Travel Plan as a scene for actors descriptions of the system and the regulation goals
Construction of a “reference project” by clustering "operational projects":
Three main scenarios:
Referring to an "island strategy" concerning automobile traffic
Safety research entails modelling
Different levels of representations of unsafe situations
Both aspects: techniques and decision making
How to make explicit the models of action
Stressing the “unspokens” of planning (importance of Ring roads, forgetting mopeds and motocycles, etc.)
The possible consequences on safety (accident scenarios)