Compared to other western cities, Frankfurt is a pretty safe place to be and crimes are rare. People are quite peaceful and very welcoming. Thefts are not unheard of so it’s advisable to avoid wandering around alone at night and to always keep your eyes and ears open for danger. In the red light district of Hauptbahnhof, drug dealers might be seen. However they are kept under control by the efficient and alert police of the city. In general there is no area that has to be specifically avoided because like any popular tourist destination, Frankfurt authorities make sure that they keep the city as desirable as possible. As a precaution, make sure your travel and medical insurance is covered before you leave home and follow all basic road rules while roaming around the city. In case of any emergency contact the police immediately and keep the following contacts in hand.