title: An illusory size-speed bias and railway crossing collisions.
abstract: Collisions between motor vehicles and trains at railway level crossings have been a high-profile issue for many years in New Zealand and other countries. Errors made in judging a train's speed could possibly be attributed to motorists being unknowingly subjected to a size-speed illusion and this could put them at considerable risk. Leibowitz (1985) maintained that a large object seems to be moving slower than a small object travelling at the same speed. Support has been provided for Leibowitz's theory from studies using simple shapes on a screen. However, the reasons behind the size-speed illusion remain unknown and there is no experimental evidence that it applies to an approaching train situation. To investigate these issues, we tested observers' relative speed estimation performance for a train and a car approaching at a range of speeds and distances, in a simulated environment. The data show that participants significantly underestimated the speed of the train, compared to the car. A size-speed illusion seems to be operating in the case of the approaching train in our simulation and may therefore be a risk factor in some railway level crossing collisions.
authors.affiliation: University of Waikato, New Zealand. hclark@waikato.ac.nz
authors.forename: Helen E
authors.initials: HE
authors.lastname: Clark
authors.forename: John A
authors.initials: JA
authors.lastname: Perrone
authors.forename: Robert B
authors.initials: RB
authors.lastname: Isler
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control*; D000328:Adult; D001334:Automobile Driving; D001336:Automobiles; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D011890:Railroads; D012858:Size Perception / Q000502:physiology*; D055815:Young Adult