Human Factors and Road Engineering Mechanism Engineering-Psychologist Dr. Sibylle Birth, SoRSA Conference, 26./27.06.

Transcription

1 Human Factors and Road Engineering Mechanism Engineering-Psychologist Dr. Sibylle Birth, SoRSA Conference, 26./ , Birmingham 1

2 Pillars of road safety Behavior (agression, alcohol) enforcement, education man-car interaction user friendly car design ROAD Surrounding man-road interaction user friendly road design car-road interaction appropriate design, grip, curve elevation, segregation of PTW,... 2

3 Human Factors Definition terminus technicus in industrial safety engineering (ca. 1930): Psychological / physiological activity patterns, that influence driver s interaction with the road e.g. limits of the perception system, information processing, activity regulation, considered are general human abilities, that are typical and stable in all road users - regardless of age, culture, race,... - regardless of temporary effects of illness, alcohol, fear, aggression Goal: identification of accident-triggers 3

4 3 Human Factors Safety Rules I. Give road users enough time! Proper anticipation, decision + reaction needs at minimum 4-6 sec II. Field of view: enable appropriate speed + lane tracking! Monotony is the greatest enemy of road user! Avoid optical illusions. Strict symmetrical, parallel and right-angel impressions in the roadside. III. Pre-programme driver s expectations correctly! Use consistent road characteristics in a logical sequence. Make inevitable changes as early and clear as possible. Instruct drivers clearly if they have to change habits, automated driving programs or expectations! 4

5 Reaction time: Road users have to see critical locations early enough! invisible pedestrian crossing visible pedestrian crossing Quelle: Stadt Kerpen Quelle: S. Birth,

6 Playing with figure-background-effects The background offers good camouflage for the herd. This trick was repeated by the evolution in thousands of variants. In road traffic this camouflage effect can become a deadly trap (source : Bernd Foehr, /07/05/farben-in-der-natur-teil-2-tarnung/) 6

7 How many signs? Proper reaction in proper time? Only quick detectable, dominant objects can attract attention What is not dominant cannot attract attention this is the same in the case of crossings, traffic lights, bus-stops, junctions, curves, traffic signs, Source : Birth, B167,

8 Narrow limits of our sense of sight from millions of years heritage the human sense of sight evolved to survive in environment with high risks: - image resolution from 16 images/sec - Colour perception from 400nm-700nm - many legendary optical illusions caused by the effect of Gestalt - perception of movements periphery - sharp central vision fovea centralis Especially while driving/flying the sense of sight leads us into various risks 8

9 Principles of Gestalt form the perception in the field of view Gestalt: dominant impression of a perceptional unit within a visual scenery. The characteristics of the unit are not explainable by summation of it s parts. Information-processing is not stable, but dynamical! What you see is unreal. The brain filters, interprets and corrects perceptional units so long as they are similar to known items This process is based on individual dispositions and is fully subconscious Source: bilder/sternbild-orion.jpg 9

10 Example: picture puzzle What do you see? A vase or two faces? 10

11 The trap: driver follows always his dominant visual impression Roads direction: orientation: to the left straight Roads direction: to the left orientation: to the left Paultan.org: Federal-Highway-motorcycle-lane Paultan.org: Federal-Highway-motorcycle-lane Cover eye-catching impressions. Signs should be visible! 11

12 What is the better curve to drive trough reliable? Source : Birth, S. Staadt, H., 2004 Need: continuous and parallel optical frame in the outer curve. 12

13 The innocence of the outer curve optical illusions Roads love jewelry dearly: hedges, bushes, fences, walls, pillars... non-parallel frames / frames with gaps) beside the road: cause run-off-road accidents Dominant temptation beside the road. Here counts: discipline of the outer frame! 13

14 Parallelism and symmetry are basics for safe driving Old trick of master builders of Renaissance: - Reduced road width, left and right road edge form converging lines - This causes an optical illusion impression of a greater distance - Why? Longer ways convey impression of greatness and wealth 14

15 Human Factor: distance illusion Distance illusion on an accident spot by a line of trees that converges to the road edge Source : Birth, S.,

16 Distance illusion ahead of a curve distance: speed: overestimated to high distance: overestimation corrected speed: calmed down Paultan.org: Federal-Highway-motorcycle-lane Paultan.org: Federal-Highway-motorcycle-lane Cover optical illusions! 16

17 Effects of Gestalt (source: Yoshihashu Murashige: markings using HF-methodologies. Case stories for Accident Investigation Guideline, PIARC. Arrow-like marking creates optical illusion and calm down speed closed line of chevrons give guidance in curve Road safety = proper road design + attention-guiding optical elements 17

18 The Illusion: 100% attention. Lawyers would like to have it so. But: - Is it possible to be attentive continuously? - How active or a passive attention? - voluntary or involuntary attention? - directed to a subject matter (statically)? - directed to a sequence of actions (dynamically)? - with which of our five senses? Try it by yourself! Make the Gradual Change Test. 18

19 Attention makes us blind? The pedestrian kept an eye on the car that came from the right. That s why he overlooked the two wheeler from the left. Attention can make us blind, because: The more attention you have for the one, the less you have for the other. 19

20 Speeding as a matter of perception Speed is a function of Monotony low number of objects contrasting with background activity level of CNS decreases feeling of tiredness subconscious speeding Source: Leitfaden Lärmschutz, Germany Curvature low curvature low activity level subconscious speeding up Visible amount of road s surface the broader and the more straight the road the higher the speed Dominant Gestalt of critical locations if critical locations (bus stop, zebra, traffic lights, ) are not optically dominant and easily perceptible inappropriate speed 20

21 Invitation for speeding 21

22 The expectation logic of drivers modifies their driving behavior What s the matter? An office building ahead. What do you see? What do you expect? What would you do? I see I expect that Thus: normal driving program! 22

23 How instruct right expectations? Use optical elements that guide attention and expectations Source : Birth, S

24 24 Results of speed measurement Ohne Signalsäule 2013 Mit Signalsäule 2013 Mit Signalsäule 2015 Exceeding speed limit of 30 km/h before: 93% after: 48% (44%) Difference in speed: Decrease of v km/h from all directions stable effect after 2 years Dr. Sibylle Birth, 2015

25 Results of HF Audit of 9 national design standards TC1.1 HF-Subgroup audited 9 national design standards with HF-Evaluation Tool Question: Are Human Factors principles integrated in national design standards? Yes: HF requirement is fully integrated in the standard Partly: HF requirement is partially integrated but it is not mentioned that it is a HF need NO: no such term/requirement is mentioned in the standard I. 6 Second Rule - Give road users enough time! II. Field of View Ensure appropriate speed+ lane tracking! III. Logic Rule Preprogramme road users behaviour correctly! Fulfilled out of 9 HF-Demands YES (Numberof countrys) PARTLY (Number of countrys) NO (Number of countrys) 50% 30% 20% 10% 30% 60% 35% 25% 40% 30% 30% 40% 25

26 Conclusion 1. Human Factors of reaction time, of field of view and the management of expectations should be integrated in road design + accident prevention 2. Human Factors should be consequently integrated in the accident investigation process 3. Designers should be trained as early as possible in the basics of ergonomical design, especially space perception and Gestalt -principles of perception 4. Road safety staff should be educated in Human Factors to prevent accidents from the root Better to prevent than to cure! 26

27 Thank you for your attention. 27