Fleischmann-Sacher effect
After a road traffic accident , statements of those involved and witnesses are usually recorded on the spot by police officers to clarify the fault. If legal proceedings are required in disputed cases , as a basis for the accident reconstruction, in addition to the analysis of tracks and vehicle damage, and above all those involved must be asked about their memories of the accident .
Testimony
Both human observation and memory are limited by psychological factors. The content of a statement cannot be properly assessed without knowledge of these limits and without taking into account certain regularly occurring "failures".
Perceptual psychological interpretation Braking start
In the 1970s, the court experts for accident reconstruction Otto Fleischmann and Fritz Sacher noticed the following phenomenon when questioning vehicle drivers in court proceedings: In the event of an emergency stop, the routine question of the accident site in which position the danger (mostly two-part vehicle ) was recognized, an objectively "wrong" position was regularly given. Namely the position of the beginning of braking that can be objectively verified on the basis of skid marks - there was no ABS yet . H. the position of the beginning of the active defense act.
After a statistical evaluation of the phenomenon , which was still unexplained at the time , Fritz Sacher, in collaboration with the traffic psychologist Fritz Meyer-Gramcko, found the psychological explanation. In an emergency situation, the experienced driver of a vehicle performs spontaneous defensive actions (braking, steering) automatically and reflexively. There is no thought process that would take too long. The braking reaction in the dangerous situation is therefore unconscious and therefore cannot be remembered . Only the active defense action, the pressing of the brake pedal , is consciously perceived and is remembered as the beginning of the reaction, although the danger was "actually" recognized at an earlier point in time.
This traffic psychological phenomenon, discovered by the SV pioneers Fleischmann and Sacher, is referred to in Austria as the Fleischmann-Sacher effect (phenomenon).
Fallacies
Ignorance of this perceptual psychological fact can lead to blatant false conclusions when reconstructing traffic accidents and is therefore of particular importance in accident analysis . If one were to take the statements “literally” without a perceptual psychological interpretation, the reaction would supposedly have been about a second late or the statement would not be technically comprehensible. One would wrongly accuse a road user of a possible causal reaction delay.
Grazing while cornering
The analogous effect can be observed when asking about the collision point during a turning maneuver, a (tight) cornering. A collision at the exit of the bend will be remembered if it "actually" occurred at the apex of the bend, one second earlier in terms of time. B. corresponds to a distance of 6 m at 20 km / h.
Individual evidence
- ↑ F. Sacher: Insufficient absorption of information as the cause of the accident. Traffic accident and vehicle technology, 6, 1993, p. 155.
- ↑ B. Wielke: Witness statements problematic, but indispensable. In: M. Rant (Ed.): Expert in Austria , Festschrift 2012 (PDF; 255 kB). ISBN 978-3-7073-2188-3 , p. 445 ff.
- ^ Fritz Meyer-Gramcko: Reason for reaction and reaction in road traffic. In: The expert 1/1978.
- ↑ Fucik, Hartl, Schlosser, Wielke (ed.): Handbook of the traffic accident, part 2, 3rd edition. Manz'sche publishing and university bookstore, Vienna 2019, ISBN 978-3-214-13814-1 .