Accident Analysis and Prevention 40 (2008) 1282–1293
A meta-analysis of the effects of cell phones on driver performance
Jeff K. Caird a,∗, Chelsea R. Willness b, Piers Steel c, Chip Scialfa b
a Cognitive Ergonomics Research Laboratory, University of Calgary, 2500 University Dr. N.W. Calgary, Alberta T2N 1N4, Canada
b Department of Psychology, University of Calgary, 2500 University Dr. N.W. Calgary, Alberta T2N 1N4, Canada
c Haskayne School of Business, University of Calgary, 2500 University Dr. N.W. Calgary, Alberta T2N 1N4, Canada
Received 11 September 2007; received in revised form 2 January 2008; accepted 30 January 2008
The empirical basis for legislation to limit cell phones while driving is addressed. A comprehensive meta-analysis of the effects of cell phones
driving performance was performed. A total of 33 studies collected through 2007 that met inclusion criteria yielded 94 effect size estimates,
th a total sample size of approximately 2000 participants. The dependent variables of reaction time, lateral vehicle control, headway and speed
d the moderating variables of research setting (i.e., laboratory, simulator, on-road), conversation target (passenger, cell phone) and conversation
pe (cognitive task, naturalistic) were coded. Reaction time (RT) to events and stimuli while talking produced the largest performance decrements.
andheld and hands-free phones produced similar RT decrements. Overall, a mean increase in RT of .25 s was found to all types of phone-related
sks. Observed performance decrements probably underestimate the true behavior of drivers with mobile phones in their own vehicles. In addition,
ivers using either phone type do not appreciably compensate by giving greater headway or reducing speed. Tests for moderator effects on RT and
eed found no statistically significant effect size differences across laboratory, driving simulation and on-road research settings. The implications
the results for legislation and future research are considered.
2008 Elsevier Ltd. All rights reserved.