The Highway Safety Acts of 1973 and 1976, and the Surface Transportation Assistance Act of 1978 provide funds to individual states to improve safety at public rail-highway crossings. This report was undertaken in support of a U.S. DOT effort to improve the efficient allocation and use of these Federal funds. The report describes the results of a study designed to collect, analyze, and document life cycle costs of active rail-highway crossing warning devices. Life cycle costs were determined from information on installation costs contained in the final billings of rail-highway crossing improvement projects and from data on maintenance costs provided by various states, railroads, and railway associations. Life cycle costs were analyzed by cost components for each of the five Federal Railroad Administration regions. Cost components included pre-engineering, labor, material, and equipment rental costs as well as maintenance costs. Cost variability due to several factors such as number of tracks, crossing location, type of train detection system, and combinations of these variables was analyzed.