This article provides guidance for the effectiveness evaluation of transpor
tation programs. It discusses the importance of determining the significanc
e of changes in outcome measures before versus after implementation of tran
sportation programs. The article reviews common weaknesses in example evalu
ations, and points to remedies, including structuring controls to help dete
rmine the effects of transportation programs, and applying readily availabl
e statistical tests to determine the significance of measured outcomes.