ETSC Best in Europe Conference 2006 Changing Human Machine Interfaces Towards the development of a testing regime Samantha Jamson University of Leeds

Current guidance on HMI European Statement of Principles (1999, updated 2005) System manufacturer guidelines “do not operate this system whilst driving” Drivers’ common sense………… Need a test regime to provide objective guidance

The challenge To design a test regime that: –Is technology-independent, i.e. does not depend on a particular technology being employed in a system design –Uses safety-related criteria –Is cost effective and easy to use –Is appropriate for a wide range of HMI –Is validated through real-world testing

A three year attempt….. Human Machine Interface And the Safety of Traffic in Europe)HASTE project (Human Machine Interface And the Safety of Traffic in Europe) Decide how to measure distraction Establish the effects of distraction on driving performance Use real tasks to validate the process Develop a draft test regime

Overall approach – Stage 1 Surrogate In Vehicle Information Systems (S-IVIS) –One cognitive, one visual –Three S-IVIS levels Assessment methods –Simulator, Laboratory and Field Road –Urban, rural and motorway –Road complexity level “Average” vs older drivers UK drivers vs Portuguese drivers 17 experiments, 527 participants

Visual distraction task

Effects of visual distraction Fewer glances straight ahead Lateral control deteriorates Speed reduction

Cognitive distraction task (auditory) Participants’ task is to maintain a count of ‘target sounds’ presented within a list, keeping a separate tally for each target sound Performance is thought to deteriorate with an increase in the number of target sounds

Effects of cognitive distraction More glances straight ahead Improved lateral control Poorer longitudinal control BaselineCognitive task

A misguided (?) conclusion…… HMI that require cognitive/auditory attention are less distracting than visual ones Not only are they less distracting, but they improve driving performance (!)

Alternative explanation Narrowing of visual gaze Attentional processes also affected by distraction Late detection and poor identification of stimuli –“I didn’t expect it,” –“I looked but failed to see,” –“I saw it too late.”

The HASTE draft test regime Driving in at least a medium-level driving simulator with a relatively small number of subjects (15 subjects are thought to be sufficient) A rural two-lane road driving situation and a duration of approximately one hour Assessment needs to take place at the level of specific tasks on the IVIS, since an IVIS may have a combination of comparatively easier and relatively harder tasks A small number of dependent variables (indicators) are sufficient. At the moment, a set of 5 indicators is recommended.

Suggested indicators Subjective rating of driver’s own performance Average speed The proportion of high frequency steering activity The minimum time headway to a lead vehicle. Reaction time on Peripheral Detection Task

Implications The mode of distraction is important Some variables are more sensitive than others Some testing environments are more useful than others –Rural road was most diagnostic in simulator Motorway was most diagnostic in field There could be implications for older drivers –managing the trade-off between driving and secondary tasks Meta analysis to obtain robust results on sensitivity, reliability, and consistency of effects, and their links to safety

Complementary methodologies A checklist could identify possible system design problems at a stage where they can still be corrected. Low cost simulators could be used in the early evaluation stage Some field trials may be necessary for older drivers (simulator sickness)

Changing HMIs – what are the options ?  Research outputs remain so  Enforced by legislation  EU  National  Issued as Commission Recommendation  Adopted voluntarily, backed up by ISO  Used as consumer information (P-NCAP) –Not legally binding

(Not) The future