After GSM-R was implemented in the Netherlands, emergency call areas where kept the same as the precursor. Due to the increasing number of trains, emergency calls led to more and more disturbances of the timetable. Arcadis has been given an assignment by ProRail to investigate the possibilities for optimizing the GSM-R areas for group calls and emergency calls. The same procedure has been done for both the group call areas and the emergency call areas. Wrong choices of emergency call areas can lead to unsafe situations so the emergency call was leading for the GSM-R area optimization project.