Maps Available Tentative standardized maps for charting the release and spread of hazardous materials at transportation accident scenes have been adopted by the National Transportation Safety Board. Using the maps, the hoard will overlay accident gas clouds, flying fragments from explosions, and burn patterns from fireballs on standard-scale maps. The resulting plots are intended to help emergency personnel with planning as well as the actual location of police and evacuation lines during future hazardous materials emergencies. Single copies of “Standardized Hazardous Materials Maps,” may be obtained without charge by writing to the Publications Branch, National Transportation Safety Board, Washington D.C. 20594. Multiple copies may be purchased by mail from the National Technical Information Service, U.S. Department of Commerce, Springfield, Va. 22151.