Copyright: Shell Brands International AG 2008

Projects & Technology

8/29/2013

Effect of driving goals on driving behaviour

Stephen Skippon, Nick Reed & Ryan Robbins

6th International Conference on Driver Behaviour & Training, Helsinki, August 2013

Driving style, fuel economy and CO2 emissions

Dynamic driving styles - high acceleration, heavy braking, close

following, overtaking and aggressive manoeuvres

• high fuel consumption and high CO2 emissions

• less safe

Yet many drivers adopt these styles:

• >50% of UK drivers exceed the speed limit on motorways (Dept. of Transport,

2012)

• 53.4% of drivers “tailgate” a leading car (Glendon & Sutton, 2005; Glendon,

2007)

Why is this so?

Self-regulation theories of driver behaviour

Risk Allostasis Theory (Fuller, 2011)

Drivers adjust their driving behaviour to fall within a target range of

task difficulty - experienced as feelings of risk

Other motivational influences have their effect by adjusting where

in the target range the feedback loop will operate, e.g.

driver is motivated to reach a destination quickly

→ higher level of feeling of risk accepted

→ feedback loop output is higher speed

Example of theories based on self-regulation of a single variable

Self-regulation theories of driver behaviour

Multiple Comfort Zone Model (Summala, 2007)

Drivers seek to keep several functional control variables within

“comfort zones”:

• Safety margin

• Good or expected progress of trip

• Rule following (avoiding violations; and conforming to social norms)

• Vehicle/road system (maintaining smooth car/road operation and

performance, etc.)

• Pleasure of driving (arising from a sense of control, and also from sensation

seeking)

Example of broader class of models of human behaviour: goal

competition or inter-goal dynamics theories (Kruglanski et al., 2002)

Inter-goal dynamics theories of human behaviour

Behaviour: result of simultaneous pursuit of

multiple goals

Goals are hierarchically organised

Some goals influence behaviour without

conscious awareness

Active goals may:

•COMPETE for control of limited

resources – especially behaviour

•CONFLICT, such that successful pursuit

of one hinders pursuit of another

•COMPLEMENT each other: the same

behaviour supports pursuit of both

People attend to those aspects of their

perceptual environments that are salient to

their most active goals

Principle Goals

Activity goals

Task goals

Goal P2

Goal A3

Goal T4Goal T3

Goal P1

Goal A2Goal A1

Goal T2Goal T1

Goal SC1 Self-Concept Goal

Goal BI1 Biological imperative

Behaviour b1 Behaviour b2 Behaviour b3 Behaviour b4 Behaviour b5 Behaviour b6 Behaviours

From moment to moment, the actor’s behaviour is

the result of a process of INTERACTIVE

ACTIVATION AND COMPETITION between her/his

active goals

Carver & Scheier, 1998; Powers, 2005; Kruglanski et al., 2002

Goals when driving: summary of findings from qualitative research in UK and Malaysia

Individual interviews, dyadic interviews and group discussions aimed

at mapping travel-related goals

Participants from two life-stage segments (young people (aged 21-25)

and adult members of families with children at home)

UK and Malaysia

Four categories of goals when driving identified:

•Journey goals (functional/instrumental goals that the driver seeks to achieve by

making the journey, or during it)

• Safety goals (functional/instrumental goals to avoid harm while driving)

•Symbolic goals (using driving style to signal something about oneself to other

people)

•Affective goals (achievement of pleasure from driving)

Research questions

1. Does conflict between goals affect driving

behaviour?

•Safety goals vs. Journey goals

•Safety goals vs. Symbolic goals

2. Are drivers’ perceptions of the performance of their

vehicles affected by the activation levels of goals for

which performance is salient?

TRL DigiCar Driving simulator

DigiCar simulator at TRL: Honda Civic

simulator vehicle; Renault vehicle

dynamics model; OKTAL SCANeR II

Vehicle dynamics updated at 100Hz;

visuals refreshed at 60Hz; data recorded at

20 Hz

Three projection screens, 210o forward field

of view; one rear screen, 60o rear field of

view

Visual scene resolution1280 × 1024 pixels

per screen

Motion system with three degrees of

freedom (pitch; roll and heave)

Participants walked up to and entered the

car as they would a real vehicle,

encouraging expectations of a close-to-

normal driving experience

Simulated route

10.2 km of rural single carriageway A-road

Appropriate UK signage and markings, and road-side features such as

trees, bushes, fences, walls and buildings.

Repeated opportunities for mid-range accelerations:

•Six sharp bends (radius 45m, turning through 100-105°)

•Twelve gentle bends (radius 90m, turning through 70°)

•Three hill climbs (gradient 1 in 8)

•Three long straight sections

Each drive took approximately 10 minutes

Participants

30 UK males: full UK manual driving licence, >5 years driving

experience, > 8,000 miles annual driving

Mean age 49.8 (SD 13.8) years - older, experienced drivers who might

be expected to have established driving styles

Two groups:

•General drivers (N =15): recruited from TRL’s participant pool

•Performance-oriented drivers (N = 15): regular buyers of premium,

performance-oriented fuel

• Assumption that this group would have more active symbolic and affective

driving goals

Design

2 × 2 mixed factorial design with one between-participants variable (driver group) and

one within-participants variable (goal condition)

Each driver completed four drives in total, two in each goals condition:

•Relaxed (no-conflict) condition: complete the route safely, driving as they normally

would

•Time-Pressured (goal conflict) condition: imagine you are late for an important

appointment - complete the route safely but as fast as you reasonably can

15-20 minutes familiarisation with the simulator prior to experimental drives

Measures:

•Mean accelerator pedal depression

•Number of gear changes

•Time out of lane (nearside)

•Perceived vehicle acceleration

•Perceived vehicle responsiveness

Effect of goal condition and driver group on dynamic driving: mean accelerator pedal depression

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

Relaxed Time Pressured Mea

n ac

cele

rato

r (g

as) p

edal

dep

ress

ion

Goal condition

Performance oriented drivers General drivers

Significant main effect of goal condition on mean accelerator pedal position (F(1,56) =

11.19; p = 0.001). Neither main effect of driver group nor goal condition × driver group

interaction were significant

Effect of goal condition and driver group on number of gear changes during drive

Main effect of driver group was nearly significant at p < 0.05: (F(1,56) = 2.98; p = 0.088). Neither main effect of goal condition nor goal condition × driver group interaction were significant

0

10

20

30

40

50

60

Relaxed Time Pressured

Num

ber

of g

ear

chan

ges

Goal condition

Performance oriented drivers General drivers

Effect of goal condition and driver group on perception of the acceleration performance of the vehicle

Goal condition × driver group interaction was significant (F(1.56) = 5.11; p = 0.027)

0

10

20

30

40

50

60

70

80

Relaxed Time Pressured Ratin

g of

per

ceiv

ed a

ccel

erat

ion

of

vehi

cle

Goal condition

Performance oriented drivers General drivers

Effect of goal condition and driver group on perception of responsiveness of the vehicle to its accelerator pedal

0

10

20

30

40

50

60

70

80

Relaxed Time Pressured

Ratin

g of

per

ceiv

ed r

espo

nsiv

enes

s of

veh

icle

Goal condition

Performance oriented drivers General drivers

Discussion: effect of goal competition

Key finding: change in relative activation of conflicting goals leads to

change in driving behaviour

Even though level of task difficulty similar between goal conditions

Finding supports view that driving behaviour results from inter-goal

dynamics – i.e. it is the resultant of the combined influences of multiple

goals, pursued simultaneously

Discussion: effect of driver group

Hypothesis: Performance-oriented drivers have chronically active

symbolic and/or affective goals that conflict with the goal to avoid harm,

so will lead to more dynamic driving compared to General drivers

Differences in driving behaviour, while in the predicted direction, were

not statistically significant

Two possible explanations:

(1) chronic activation of symbolic and/or affective goals made no

significant difference to these driving behaviours

(2) in fact little difference in chronic goal activation between the

driver groups

Recruitment based on fuel purchasing behaviour - indirect way to try to

create inter-group differences in goal activation

Discussion: perception of performance

General drivers:

•Perceived acceleration was HIGHER in the Time Pressured condition

• Made more extensive use of the accelerator pedal – i.e. to make faster

accelerations

Thus their own goal-directed behaviour afforded more experience of acceleration

during the Time Pressured drives, and they mis-attributed this to the car having

faster acceleration performance

Performance-oriented drivers:

•Perceived acceleration was LOWER in the Time Pressured condition

•Also made more extensive use of the accelerator pedal in this condition

Speculation: performance-oriented drivers set themselves a high target rate of

progress towards the journey goal, experienced negative affect on failing to

achieve this rate (Carver & Scheier, 1998), thus experienced the acceleration of the

car as inadequate in relation to the journey goal

Conclusions

This study provides evidence that driving behaviour is not

just determined by self-regulation aimed at a single goal,

but rather results from inter-goal dynamics – i.e. it is the

resultant of the combined influences of multiple goals,

pursued simultaneously

Acknowledgments

Thank you for your attention!

The authors would like to acknowledge the contribution of Lena

Weaver of TRL for running the driving simulator experiment, and

thank our participants for helping us carry out the study

References

Carver, C.S. & Scheier, M.F. (1998). On the Self-Regulation of Behavior. Cambridge, England:

Cambridge University Press.

Department for Transport (2012). Table SPE0101, Transport Statistics Great Britain:2012, p216.

Retrieved from https://www.gov.uk/government/publications/transport-statistics-great-britain-2012, 21

January 2013.

Fuller, R. (2011). Driver Control Theory. In B.E. Porter (Ed.), Handbook of Traffic Psychology.

Amsterdam, Netherlands: Elsevier.

Glendon, I. (2007). Driving violations observed: An Australian study. Ergonomics, 50, 1159-82.

Glendon, I. & Sutton, D.C. (2005). Observing motorway driving violations, in Contemporary Issues in

Road User Behaviour and Safety, edited by D.A. Hennessey and D.L. Wiesenthal. New York: Nova

Science, 81-100.

Kruglanski, A.W., Shah, J.Y., Fishbach, A., Friedman, R., Chun, W.Y. & Sleeth-Keppler, W. (2002). A

theory of goal systems. In M.P. Zanna (Ed.) Advances in Experimental Social Psychology, Vol. 34, pp.

331-378. San Diego, CA: Academic Press.

Powers, W.T. (2005). Behavior: the control of perception (2nd edition). New Canaan, CT: Benchmark

Publications.

Summala, H. (2007). Towards Understanding Motivational and Emotional Factors in Driver Behaviour:

Comfort Through Satisficing. In P.C.Cacciabue (Ed.), Modelling Driver Behaviour in Automotive

Environments: Critical Issues in Driver Interactions with Intelligent Transport Systems. London,

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