Phoning, texting, operating a navigation system, and following route guidance

(1)

3-9-2012

Phoning, texting, operating a navigation

system, and following route guidance while

driving.

Phoning, texting, operating a

navigation system, and following

route guidance while driving.

Allert Knapper, Marjan Hagenzieker & Karel Brookhuis Delft University of Technology, TPM, Transport & Logistics

(2)

Outline

• 18 slides (this is no. 2)

• Short: background • Method • Results • Conclusions • Next steps • Questions

(3)

Driver distraction: Background

• Diversion of attention away from driving, to a

competing task (Basacik & Stevens, 2008; Lee et al. 2009)

• Dingus et al. (2006): In 80% of crashes, 65% of

near-crashes, the driver was looking away from the road ahead.

(4)

Aims

• Mobile phone:

• Conversation (hand-held)

• Texting

• Navigation system:

• Following route guidance (vs using a paper

map)

• Destination Entry

• In naturalistic driving (Interaction project)

• In a field test (Interaction), and

(5)

Participants

• 20 participants, 1 suffered from simulator sickness.

• 19 participants left:

• 13 male, 6 female

• Age range: 27 – 59, M=37 (10)

• Years drivers’ licence: M=15,1 (9.36)

• Drove at least 10.000 km per year, M=23,513

(15,100)

• Use Mobile phone + navigation system at least

(6)

Driving simulator

• ST Software, 2 webcams

• Airconditioned room, 20 degrees

celsius

• 2 distinct tracks, resembling an

existing route in the Delft –

Leidschendam area (used in the

• Field test)

Area Length Limits Character Tasks

Track 1

Leidschen-dam -Delft 10 km 9 km 50 km/h 100 km/h Urban Motorway *RG vs MAP *Destination entry

*Texting

Track 2

(7)

Experimental design

• 4x2 design, each participant met all conditions (within subjects)

• Reverse counterbalancing for route order, partial

counterbalancing for task on track 1.

Device Mobile Phone Navigation system

Task Talking Texting Way finding Destination entry

Experimental Distracted Distracted Route

guidance Distracted

Baseline Normal Normal Paper map Baseline

Track 2 (Delft ring)

1 (motor-way)

(8)

Procedure

• At least 7 days between 2 appointments.

• Each appointment 2 drives, in between drives filling

in of questionnaires (RSME, DBQ, INTERACTION questionnaire)

(9)

In-vehicle tasks

‘Device’ Task Example Characteristics

Phone

conversation Participants’ own phone Handheld, with remote researcher, questionnaire (INTERACTION) True or false, listing, describing, repeating, logical questions. Texting Participants’

own phone Text a sentence Altijd is kortjakje ziek, midden in de week maar zondags niet. 50-63 characters including spaces. (NB: Kortjakje is always ill, everyday of the week, except for Sundays)

Wayfinding Paper map vs

voice+arrow Drive from red arrow to red star vs follow route guidance

See next slide

Destination

(10)

(11)

Dependent variables

• 6 seconds of video (like in Klauer et al. 2006) for each condition

(8 per person)

• RSME (Zijlstra & Van Doorn 1985) scores for each condition

(experimental & control):

• Please indicate, by marking the vertical axis below, how much effort

it took for you to complete the destination entry task while driving

• Speed

• SD Speed

(12)

Results

Phone conversation (hand-held)

Phone Base-line Phone Base-line Phone Base-line Phone Base-line Speed limit 50 70 80 100 Mean speed 51.26 47.74 77.10* 85.36* 69.50* 75.00* 79.70* 96.67* SD speed 6.34 7.08 6.02 5.94 3.89* 2.98* 2.70* 1.79* SDLP 0.133 0.142 0.221 0.172 0.252 0.211 0.213 0.227 %TEOR 6.15* 15.79* RSME (overall) 73.78* 37.53* * P < .05 (2-tailed)

(13)

Results

Texting Texting Baseline Speed limit 100 100 Mean speed 90.83* 106.45* SD speed 1.59* 1.02* SDLP 0.312* 0.199* %TEOR 50.27* 22.53* RSME 85.16* 32.84* * P < .05 (2-tailed)

(14)

Results

Navigation system Destination entry Baseline Following route guidance Paper map Speed limit 50 50 50 50 Mean speed 41.99* 50.65* 46.09* 44.15* SD speed 2.47 2.42 3.31 3.32 SDLP 0.257* 0.138* 0.159 0.161 %TEOR 64.47* 22.85* 15.23 19.07 RSME 79.37* 41.47* 50.63 67.89 * P < .05 (2-tailed)

(15)

More effort, lower speed

0 20 40 60 80 100 120 RSME Speed

(16)

SDLP, glancing during visual-manual

tasks

0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0 10 20 30 40 50 60 70

Texting Texting baseline Destination entry Destination entry Route guidance Map

%TEOR SDLP

(17)

17

Mobile phone and navigation system use while driving

Conclusions

• Compensatory effects: More effort put into

performing a task - slower driving (TCI Fuller)

• Visual – manual task (texting, destination entry):

deteriorated lanekeeping, eyes off the road for long time.

• Phoning: somewhat more time eyes on forward

screen.

• No differences between driving with route guidance

(18)

(19)

Policy advice

• Controlled studies do not suffice; patterns of use, induced

task vs choosing a calm moment.

• So next step:

• Naturalistic driving

(20)