Epidemiology. From the Greek “epi,” meaning “among,” and “demos” meaning “the people.” In modern usage, epidemiology is the study of disease in populations. Professor Edwards uses this term for the “disease” of road traffic accidents. He has done extensive research on this in relation to reduced street lighting, by compiling data from scores of municipalities in Britain and has come to the conclusion that… well you’ll have to listen to the episode. Phil Edwards is a Professor of Epidemiology & Statistics at the London School of Hygiene & Tropical Medicine, one of the world's leading public health universities. His research has focused on road safety (particularly of pedestrians), and he has used interrupted time series analysis methods to evaluate the effects of 20 mph traffic speed zones on road injuries in London and the effects of reduced street lighting on road casualties and crime in England. Most recently, he has researched construction site injuries in lower income countries, where rapid urbanization requires construction on an unprecedented scale.