Some taxi companies used callboxes before the introduction of two-way radio dispatching, as a way for drivers to report to the dispatch office and receive customer requests for service. Taxi callboxes would be located at taxi stands, where taxis would queue for trips.
Also before the introduction of two-way readios, some police agencies installed callboxes at street locations as a way for beat officerss to report to their dispatch office. Before the development of emergency telephone numbers and the proliferation of mobile phones, some firefighting agencies installed callboxes at various street locations, so that a pedestrian or driver spotting a fire could quickly report it.
On many North American college and university campuses today, callboxes are installed at various locations around campus so that students, faculty, or staff can contact campus security in case of an emergency.
Also, callboxes also exist at regular intervals along the sides of many highways and rapid transit lines around the world, where drivers or passengers can use them to contact a control centre in case of an accident or other emergency. In rapid transit systems, such callboxes are often marked by a blue light.