Testing models of Driver Behaviour Ben Lewis-Evans

Why? Do people drive like this

Why? Do people drive like this

The Answer? MODELS!

Some have been tested

Utility Models “… people… run risks, but they do not take them” Wagenaar (1992) Trading off risks and safety to get the optimal benefit

Attitude Models “…accidents are not caused by risky attitudes but by risky behaviour” Rothengatter et al (1989) Attitude Intention Behaviour

But most have not

Time for SCIENCE! So?

Experiment One Behavioural Adaptation to Road Width Lewis-Evans & Charlton (2006)

METHOD DS9 Driving Simulator 49 participants (25 ♂ 24 ♀) All full licence holders 23.8 years old on average Speed, ratings, & open questions

METHOD Four Roads Practice Control (E) Wide (S) Narrow(W) - 2m + 3m

Narrow(W) Control (E) Wide (S)

RESULTS Speed * * * * * statistically significant difference (at least p < .05)

RESULTS Ratings * * * * statistically significant difference (at least p < .05)

RESULTS What was different? “Road Width” 10 people , only 1 correct “Nothing” 8 people Narrow road had more “Curves” 14 people Many non-factual responses e.g. narrow road had more trucks

CONCLUSIONS Impact of (narrow) road width on speed Associated with increases in risk and task difficulty Awareness of road width changes low Experiment 1

Experiment Two Speed and the assessment of risk, difficulty, effort and comfort Lewis-Evans & Rothengatter (2009)

Fuller, McHugh & Pender (2008) 3 road types Digitally altered video Increasing 5 mph increments Task difficulty and Risk (feeling & probability)

Fuller, et al (2008) Residential

Fuller, et al 2008 “…task difficulty and feelings of risk are continuously present variables which inform driver decisions…”

METHOD 47 participants (25 ♂ 22 ♀) Observation & Driving Two roads: urban & rural ~20-21 years old 9 randomly presented speeds (10 km/h increments + Free choice)

METHOD Speed data + Subjective ratings Task difficulty Feeling of Risk Crash risk Effort Comfort Habit/Typicality

Residential – Fuller et al (2008) RESULTS Averaged Driving Residential – Lewis-Evans & Rothengatter (2009)

RESULTS Averaged Driving Residential

RESULTS Relative to free speed choice Residential

CONCLUSIONS Fuller et al (2008) not replicated Threshold or U-shaped trends Habit appears to be important Experiment 2 Task difficulty, feeling of risk, & effort highly correlated

Experiment Three Close following - risk, difficulty, effort and comfort Lewis-Evans, de Waard, & Brookhuis (2010)

Subjective impressions; Constant or Threshold?

METHOD 40 participants (20 ♂ 20 ♀) 17 Inexperienced, 23 Experienced Residential road, left & right side 9 randomly presented following distances (0.5 to 4.0 sec + Free choice) 50 km/h METHOD

METHOD Distance + Subjective ratings Task difficulty Feeling of Risk Crash risk Effort Comfort Typicality

RESULTS Averaged

RESULTS Relative to free choice

CONCLUSIONS Threshold trends again Experiment 3 Habit appears to be important Task difficulty, feeling of risk, & effort highly correlated No impact of Experience or side of road

Experiment Four Speed maintenance under cognitive load Lewis-Evans, de Waard, & Brookhuis (2011)

Question What is the impact of secondary mental workload on these trends?

METHOD Four conditions (1 min) Baseline sets speed Baseline +/- 0 to 30 km/h Return to Baseline Baseline +/- 0 to 30 km/h + PASAT Counter balanced

PASAT Paced auditory serial addition task 4 2 3 1 … 6 5 4

METHOD 53 participants (21 ♂ 32 ♀) Speed data + Subjective ratings Task difficulty Feeling of Risk Effort Comfort Typicality

RESULTS Ratings Baseline vs Return to baseline

RESULTS Ratings Baseline vs Experimental * * * * * * * * * * * * * * * * * * statistically significant difference (at least p < .05)

RESULTS Ratings Experimental vs PASAT * * * * * * * * * * * * * * * * * * * * * * statistically significant difference (at least p < .05)

RESULTS Speed Baseline vs Return to baseline * * * * * * * statistically significant difference (at least p < .05)

RESULTS Speed Experimental vs PASAT * * * * statistically significant difference (at least p < .05)

CONCLUSIONS Experiment 4 Threshold trends still apparent Speed control habitual Unintentional Speeding Mental workload shifts them

Experiment Five Unfelt emotions and speed Lewis-Evans, de Waard, Jolij & Brookhuis (2012)

Emotions are important Behaviour is maladaptive without them

i.e. Vulcans are wrong

Unfelt Emotions? Emotions: physiological reaction Feelings: conscious awareness

Driving is automatic So can unfelt emotions affect it? Much of

How to test? Ethics committees take a dim view of the above

Godzilla Why? Do people drive like this

METHOD Masked Images Deception: Images part of a “memory task”

METHOD 113 initial participants (39 ♂ 74 ♀) - 8 saw (6 ♂ 2 ♀) - 19 “suspicious” (7 ♂ 12 ♀) = 85 participants (26 ♂ 59 ♀) Speed, subjective, bio

Masks Arousal 2.76 Valence 4.97 800 ms Neutral Arousal 2.78 Valence 4.86 32 ms Negative Arousal 6.59 Valence 1.80 32 ms METHOD Images

High Arousal Low Arousal High Valence Low Valence Excited Scared Bored Relaxed Masks Neutral Negative

RESULTS Speed

RESULTS Physiological Task effect HR HRV Order x Image effect HR HRV Neu to Neg Neg to Neu HR HRV

RESULTS Subjective & Memory task No consistent effects on ratings of risk or effort Good performance on the “memory task”

CONCLUSIONS Experiment 5 Images supressed time on task effects Unconscious influences on driving Gender? No support for any particular model

In Conclusion People may run risks, but they do not usually feel them But what they do not feel may still affect them

The Moon Thank You Questions? b.lewis.evans@rug.nl

References Fuller, R., Bates, H., Gormley, M., Hannigan, B., Stradling, S., Broughton, P., Kinnear, N., & O’Dolan, C. (2008). The Conditions for Inappropriate High Speed: A Review of the Research Literature from 1995 to 2006. London: Department for Transport. Fuller, R., McHugh, C., & Pender, S. (2008). Task difficulty and risk in the determination of driver behaviour. Revue Européenne De Psychologie Appliquée/European Review of Applied Psychology, 58(1), 13-21. Lewis-Evans, B., & Charlton, S. G. (2006). Explicit and implicit processes in behavioural adaptation to road width. Accident Analysis & Prevention, 38(3), 610-617. Lewis-Evans, B., & Rothengatter, T. (2009). Task difficulty, risk, effort and comfort in a simulated driving task— Implications for Risk Allostasis Theory. Accident Analysis & Prevention, 41(5), 1053-1063. Lewis-Evans, B., de Waard, D., & Brookhuis, K. A. (2010). That's close enough—A threshold effect of time headway on the experience of risk, task difficulty, effort, and comfort. Accident Analysis & Prevention, 42(6), 1926-1933. Lewis-Evans, B., de Waard, D., & Brookhuis, K. A. (2011). Speed maintenance under cognitive load – Implications for theories of driver behaviour. Accident Analysis & Prevention, 43(4), 1497-1507. Lewis-Evans, B., de Waard, D., Jolij, J., & Brookhuis, K. A. (2012). What You May Not See Might Slow You Down : Masked Images and Driving. PloS One, 7(1), e29857. Rothengatter, J. A., De Bruin, R. A., & Rooijers, A. J. (1989). The effects of publicity campaigns and police surveillance on the attitude-behaviour relationship in different groups of road users. Proceedings of the Second European Workshop on Recent Developments in Road Safety Research, France. 197- 202. Wagenaar, W. A. (1992). Risk taking and accident causation. In J. F. Yates (Ed.), Risk-Taking Behaviour . , Englewood Cliffs, NJ: John Wiley & Sons.