risk assessment in special events

tehran with a population over 12 million people is considered as a mega city in the world. this city is also the capital of a county with a population over 70 million people and its own beliefs and special occasions. national and religious events, as well as the historical events, are of high importance. the independence day (bahman 22), eid al-fitr prayer, imam khomeini death anniversary and… are the most important events that are held in tehran. risk management and providing safety and security maintenance for passengers and equipment's are the most significant issues. this paper states years of experience with risk management in these special events in tehran and metro stations; and indicates particular points, problems and difficulties of coordinating the whole public transportation systems. in addition a comparison will draw between implementing events in iran and london.