A1 Journal article (refereed)
On the Difference Between Necessary and Unnecessary Glances Away From the Forward Roadway : An Occlusion Study on the Motorway (2020)

Kircher, K., Kujala, T., & Ahlström, C. (2020). On the Difference Between Necessary and Unnecessary Glances Away From the Forward Roadway : An Occlusion Study on the Motorway. Human Factors, 62(7), 1117-1131. https://doi.org/10.1177/0018720819866946

JYU authors or editors

Publication details

All authors or editorsKircher, Katja; Kujala, Tuomo; Ahlström, Christer

Journal or seriesHuman Factors



Publication year2020


Issue number7

Pages range1117-1131

PublisherSage Publications, Inc.

Publication countryUnited States

Publication languageEnglish


Publication open accessNot open

Publication channel open access

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/66718


The present study strove to distinguish traffic-related glances away from the forward roadway from non-traffic-related glances while assessing the minimum amount of visual information intake necessary for safe driving in particular scenarios.

Published gaze-based distraction detection algorithms and guidelines for distraction prevention essentially measure the time spent looking away from the forward roadway, without incorporating situation-based attentional requirements. Incorporating situation-based attentional requirements would entail an approach that not only considers the time spent looking elsewhere but also checks whether all necessary information has been sampled.

We assess the visual sampling requirements for the forward view based on 25 experienced drivers’ self-paced visual occlusion in real motorway traffic, dependent on a combination of situational factors, and compare these with their corresponding glance behavior in baseline driving.

Occlusion durations were on average 3 times longer than glances away from the forward roadway, and they varied substantially depending on particular maneuvers and on the proximity of other traffic, showing that interactions with nearby traffic increase perceived uncertainty. The frequency of glances away from the forward roadway was relatively stable across proximity levels and maneuvers, being very similar to what has been found in naturalistic driving.

Glances away from the forward roadway proved qualitatively different from occlusions in both their duration and when they occur. Our findings indicate that glancing away from the forward roadway for driving purposes is not the same as glancing away for other purposes, and that neither is necessarily equivalent to distraction.

Keywordstraffic behaviourmotor vehicle driversattentioneye tracking

Free keywordsdriver behavior; attention; distraction; occlusion; glance behavior

Contributing organizations

Ministry reportingYes

Reporting Year2020

JUFO rating2

Last updated on 2024-22-04 at 13:45