Visual and Task Demands of
Driver Information Systems

Paul Green

April 7, 1998

This report summarizes the research pertaining to visual demands and the use of complex in-vehicle information systems. Issues addressed in this report and supporting documentation include:

1. What do existing guidelines require concerning the use of navigation systems while a motor vehicle is in motion?
2. According to the literature, how much time is available to glance inside the vehicle when vision is occluded?
3. When people are free to glance inside a vehicle, what are the glance durations?
4. What is the relationship between glance duration and ratings of comfort/safety?
5. How much time do drivers actually spend glancing at in-vehicle displays?
6. How long do statically tested input-related navigation system tasks take to complete?
7. When drivers focus on in-vehicle tasks, when do lane departures occur? What is the relationship between task completion time, mean number of glances, mean and total glance time, and lane departures for existing interfaces?

The literature suggests that while driving on a reasonably straight road in light to moderate traffic, drivers are able to allocate 2 eye fixations of 1.5 s or less to in-vehicle displays. Except for situations of no traffic, longer glance durations pose an unacceptable risk to drivers. Further, situations where 3 or 4 glances are needed sometimes may be acceptable in extremely easy situations. In no situation should more than 4 glances be required to an instrument panel function in a moving vehicle.

Graphical Abstract (.pdf) | UMTRI-98-16 Full Report (.pdf)


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