GIS allows emergency responders to access more accurate tactical information necessary for preplanning and responding more quickly and effectively to various types of emergencies. GIS can document such features as the age of the affected population; whether they are likely to provide their own transportation; the location of the elderly, handicapped, and children; and the number of vehicles a road can tolerate. When information on hazards, property, and critical infrastructure is combined with risk and probability, emergency managers can begin to develop mitigation, preparedness, response, and recovery plans. Examples of GIS uses for local public safety agencies include map production, incident resolution (mobile GIS), and department-level analysis. GIS also serves public health by providing information on health needs during disasters. GIS data on building layouts, hydrants, addresses, and streets can be used to help responders locate incidents en route, identify flow ratings of the nearest fire hydrants, or accurately decide where to place dams across a storm water line to stop the spread of a hazardous material spill. Emerging trends within law enforcement and emergency management are toward shared planning and execution. This is facilitated by GIS, Web-based 3-D data dissemination and visualization technology, E-911, and tracking that use radio frequency identification and the global positioning system.