Citation

Sando T, Mohr D. Accid. Anal. Prev. 2012; 45: 826-827.

Affiliation

School of Engineering, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224, United States.

Copyright

(Copyright © 2012, Elsevier Publishing)

DOI

10.1016/j.aap.2011.08.005

PMID

22269575

Abstract

Before-and-after safety studies are becoming more desirable in lieu of traditional cross-sectional studies in establishing crash modification factors, especially after the introduction of the first version of the Highway Safety Manual (2010). We present a simple method for estimating necessary sample sizes to obtain a target precision or power when the effect is represented as a proportional change in a Poisson rate. We also show that necessary sample sizes are not very different when full Bayesian models are implemented.

Language: en