Brief Communications

Nature 401, 35 (2 September 1999) | doi:10.1038/43360

Why cars in the next lane seem to go faster

Donald A. Redelmeier & Robert J. Tibshirani1

Switching lanes while driving along a busy road can be a risky manoeuvre. It is often instigated on the driver's judgement that the cars in the next lane are moving faster than those in the driver's own lane. But faulty intuition1, 2, 3 may cause people to overestimate the speed of vehicles in the next lane, believing that they are moving faster even when both lanes have the same average speed. We suggest that this illusion occurs because more time is generally spent being overtaken (passed) by other vehicles than is spent in overtaking them. Knowing that this effect is illusory might encourage drivers to resist small temptations to change lanes.

  1. Departments of Health Research and Policy and of Statistics, Stanford University, Stanford, California 94305-5405, USA

Correspondence to: Donald A. Redelmeier University of Toronto, Sunnybrook and Women's College Health Sciences Centre, G-151, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
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