A comprehensive synthesis of the experimental and numerical results for turbulent flow over rough surfaces presented in Chaps. 4 and 5 is presented. Turbulence statistics for both experiment and simulation are tabulated including both data presented in this book and in the references. Analysis of the applicability of Townsend’s similarity hypothesis is presented in reference to mean velocity defect, mean temperature defect, Reynolds stress, heat flux, and turbulence spectra. Results for turbulence structure and comparison with smooth wall behavior is presented. Areas for future research are emphasized.