Comparison of manual vs. speech-based interaction with in-vehicle information systems Driving Behavior Simulation Lab Jannette Maciej ∗, Mark Vollrath Department of Engineering and Traffic Psychology, Technische Universitat Braunschweig, Gausstrase 23, D Braunschweig, Germany 報告者：楊子群

O M S A E P R Compared operating these either by a touch screen or a speech interface. A hand-free mobile phone car kit Music section system Two different navigation The two navigation systems differed in the way the speech interface was designed enabling us to also obtain some results on the importance of interface design to driving safety. Objective Driving Behavior Simulation Lab

1.Driving task 2.Secondary tasks Method Driving Behavior Simulation Lab O M S A E P R

1.Driving task (1/5) Use the Lane Change Task(LCT;Mattes,2003)to evaluate the distraction case by the different in-vehicle information systems(IVIS).  LCT simulation 1. Straight section of a three-lane road. 2. Cannot drive Speed faster than 60 km/h. 3. At some point signs are introduced which become legible at certain distance. (Indicate driver should change the lane as soon as possible) Method Driving Behavior Simulation Lab O M S A E P R

1.Driving task (2/5) Creating this task was to assess the perdormace in two basic components of the driving task. Lane-keeping Lane-changing The advantage to LCT is to create well-defined level of the driving task difficulty which requires frequent attention of the driver.  Eighteen lane change, that is to say “one lane change every 10s”. Method Driving Behavior Simulation Lab O M S A E P R

1.Driving task (3/5) One trial consists of: random sequence to 18 lane changes (left vs. right,movement across one lane vs.movement across two lane) ---total time ： 3min. Method Analysis Lane- changing Lane- keeping SDLP (Standard deviation of the lateral position) Reaction time Mean deviation Driving Behavior Simulation Lab O M S A E P R

1.Driving task (4/5) Subjective distraction Gaze behavior Drivers rated their perceived distraction into two step.  First step Five verbal categories ranging form “very little” to “very strong”  Second step Once more using a 3-point scale ( - / 0 / + ) This procedure gives reliable data on a 15-point-scale( 5 x 3 ) Method Driving Behavior Simulation Lab O M S A E P R

1.Driving task (5/5) Subjective distraction Gaze behavior Following the experiment, using the software INTERACT.  Gaze classified as either: 1.Looking at the screen of the LCT. 2.Looking away from the screen towards the secondary task.  Data: Gaze percentage = away screen(LCT) duration time / total driving time Method Driving Behavior Simulation Lab O M S A E P R

2.Secondary tasks Compare manual vs. speech-based four IVIS were examined. 1.Selection same music database. Manual condition >> MP3-Player Speech condition >> Laptop-based prototype music selection system 2.Call by specifying the name and type of the contact. hands-free car kit 3.Navigation system was used for two tasks. ( touch screen 、 voice command ) (1)Enter specific point-of-interests(POI) in several cities. (2)Enter an address. Method Driving Behavior Simulation Lab O M S A E P R

 30 drivers 16 male. 14 female.  Demands of condition Normal vision (inccorrected).  Age Rang ed from 19 to 59. Mean age of 33.2(SD=11.9).  Experiment time Two to three hours. Subjects Driving Behavior Simulation Lab O M S A E P R

Apparatus Driving Behavior Simulation Lab O M S A E P R  Standard PC equipped Joystick steeringwheel Gas Brake pedal

 Within-subjects design  Interface Manually Via Speech Driving the LCT which adds up to eight condition. Additionally,as a ninth condition the second navigation system for address entry. Secondary tasks and order of the interaction mode(manual vs. speech) was randomized. Experimental design Driving Behavior Simulation Lab O M S A E P R MusicPhonePOIMultiple ManualCondition 1Condition 2Condition 3Condition 4 SpeechCondition 5Condition 6Condition 7Condition 8

Procedure Introducedconsent forms How to manage the LCT driving tasks Six practice trials perceived distraction Experiment END Baseline Music Phone Points-of-interests(POI) Multiple Single Baseline Music Phone Points-of-interests(POI) Multiple Single Driving Behavior Simulation Lab O M S A E P R

 The aim of the study is to examine reduces the distraction. (speech operation compared to manual-visual)  To this aim, a 4×2 (four IVIS×two modes of operation)repeated measures MANOVA. Results Driving Behavior Simulation Lab O M S A E P R Main effects Interaction High significant

Results Driving Behavior Simulation Lab O M S A E P R For the POI entry For the address entry

Results Driving Behavior Simulation Lab O M S A E P R For the telephone IVIS For the music selection

Results Driving Behavior Simulation Lab 12 No advantage of the speech control could be shown O M S A E P R

Results Driving Behavior Simulation Lab Significant increase Exception being the point-of-interest entry O M S A E P R

Results Driving Behavior Simulation Lab Significant increase in all tasks Due to drivers saw the sign in advance(could not read it) O M S A E P R

Results Driving Behavior Simulation Lab 30-40% of the time was used to look at the displays.(mean duration:0.7 to 1s) Substantially reduced by the speech control O M S A E P R

Results Driving Behavior Simulation Lab Subjective distraction was stronger for manual than for speech O M S A E P R

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