title: Street crossing behavior in younger and older pedestrians: an eye- and head-tracking study.
abstract: BACKGROUND
  Crossing a street can be a very difficult task for older pedestrians. With increased age and potential cognitive decline, older people take the decision to cross a street primarily based on vehicles' distance, and not on their speed. Furthermore, older pedestrians tend to overestimate their own walking speed, and could not adapt it according to the traffic conditions. Pedestrians' behavior is often tested using virtual reality. Virtual reality presents the advantage of being safe, cost-effective, and allows using standardized test conditions.
  
  
  METHODS
  This paper describes an observational study with older and younger adults. Street crossing behavior was investigated in 18 healthy, younger and 18 older subjects by using a virtual reality setting. The aim of the study was to measure behavioral data (such as eye and head movements) and to assess how the two age groups differ in terms of number of safe street crossings, virtual crashes, and missed street crossing opportunities. Street crossing behavior, eye and head movements, in older and younger subjects, were compared with non-parametric tests.
  
  
  RESULTS
  The results showed that younger pedestrians behaved in a more secure manner while crossing a street, as compared to older people. The eye and head movements analysis revealed that older people looked more at the ground and less at the other side of the street to cross.
  
  
  CONCLUSIONS
  The less secure behavior in street crossing found in older pedestrians could be explained by their reduced cognitive and visual abilities, which, in turn, resulted in difficulties in the decision-making process, especially under time pressure. Decisions to cross a street are based on the distance of the oncoming cars, rather than their speed, for both groups. Older pedestrians look more at their feet, probably because of their need of more time to plan precise stepping movement and, in turn, pay less attention to the traffic. This might help to set up guidelines for improving senior pedestrians' safety, in terms of speed limits, road design, and mixed physical-cognitive trainings.
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. giuseppe.zito@artorg.unibe.ch.
authors.forename: G A
authors.initials: GA
authors.lastname: Zito
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. dario.cazzoli@artorg.unibe.ch.|ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland. dario.cazzoli@artorg.unibe.ch.
authors.forename: D
authors.initials: D
authors.lastname: Cazzoli
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. loreen.scheffler@students.unibe.ch.
authors.forename: L
authors.initials: L
authors.lastname: Scheffler
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. michael.jaeger@artorg.unibe.ch.
authors.forename: M
authors.initials: M
authors.lastname: Jäger
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. rene.mueri@insel.ch.|Perception and Eye Movement Laboratory, Division of Cognitive and Restorative Neurology, Department of Neurology, University Hospital Inselspital, University of Bern, Bern, Switzerland. rene.mueri@insel.ch.|Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland. rene.mueri@insel.ch.
authors.forename: R M
authors.initials: RM
authors.lastname: Müri
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. urs.mosimann@gef.be.ch.|University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland. urs.mosimann@gef.be.ch.|Private Hospital Wyss, Münchenbuchsee, Switzerland. urs.mosimann@gef.be.ch.
authors.forename: U P
authors.initials: UP
authors.lastname: Mosimann
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. thomas.nyffeler@luks.ch.|Perception and Eye Movement Laboratory, Division of Cognitive and Restorative Neurology, Department of Neurology, University Hospital Inselspital, University of Bern, Bern, Switzerland. thomas.nyffeler@luks.ch.|Center of Neurology and Neurorehabilitation, Luzerner Kantonsspital, Spitalstrasse, Luzern, Switzerland. thomas.nyffeler@luks.ch.
authors.forename: T
authors.initials: T
authors.lastname: Nyffeler
authors.affiliation: Department of Psychology, University of Bern, Bern, Switzerland. fred.mast@psy.unibe.ch.|Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland. fred.mast@psy.unibe.ch.
authors.forename: F W
authors.initials: FW
authors.lastname: Mast
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. tobias.nef@artorg.unibe.ch.|ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland. tobias.nef@artorg.unibe.ch.
authors.forename: T
authors.initials: T
authors.lastname: Nef
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control / Q000523:psychology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001288:Attention / Q000502:physiology*; D001519:Behavior / Q000502:physiology*; D003198:Computer Simulation; D003657:Decision Making; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D019416:Head Movements / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D000069636:Pedestrians / Q000523:psychology*; D016138:Walking / Q000523:psychology; D055815:Young Adult