United States Department of Transportation
i
Predicting driver distraction using computed occlusion task times : estimation of task element times and distributions.
-
2015-04-01
-
[PDF-3.01 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:To determine conformance with NHTSA’s visual-manual interface distraction guidelines and to
reduce the associated number of crashes, NHTSA recommends a visual-occlusion test
procedure. As an alternative to testing subjects following that procedure, this report provides
experimentally based estimated times for in-vehicle task elements (e.g., flick, press button).
Those estimated times can be summed and then adjusted using Pettitt’s method (which assumes
that visual tasks progress only when the test goggles are open) to estimate total task occlusion
time. The estimated times were determined from a frame-by-frame analysis of data from an
occlusion experiment evaluating a next-generation Hyundai navigation radio.
That analysis revealed the mean element time for middle-aged subjects (45-55) was only about
16% longer than young (25-35) subjects, whereas the mean task time was 44% greater,
primarily because there were 32% more occurrences of elements to complete tasks.
The elements and their mean times were flick (0.50 s), flick/scroll return (0.38 s), press button
(0.64 s), quick flick (0.35 s), reach for button (0.42 s), reach for center console (0.75 s), read
instructions (0.53 s), scroll (0.66 s), search (0.54 s), stop screen (0.24 s), turn knob (0.43 s),
reposition hand on knob (0.33 s), wait-loading (0.90 s), wait after loading (0.92 s), wait for
goggles-known location (1.34 s), and wait for goggles-unknown location (0.92 s). Most element
distributions were lognormal. Interestingly, 45% of all element occurrences were when the
goggles were closed or in open-closed or closed-open periods. Given this, the assumptions of
Pettitt’s method need further thought.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
