Relation between glance-times at an in-vehicle HMI system and number of letters displayed on it

Abstract

This paper reports the relation between glance-times at the screen of an in-vehicle HMI (Human-Machine Interface) system near the driver’s seat and the number of letters and characters dis-played on it. Our experimental results and discussion provide the fundamentals of a design method for HMIs operated by drivers to minimize glance-times. We conducted an experiment with a driving simulator to collect such data as time to read words displayed on in-vehicle HMIs while participants drove on an experimental course. The results indicate that for driving safety, the number of letters and characters displayed on an in-vehicle HMI screen should be less than 120.