An important aspect during the planning of commuter trains is how long they will be waiting at the platform. All travelers must be able to board and get off the train in time while the process cannot take too long. The train’s waiting time is called its dwell time, and this is a study of how the dwell time of the commuter trains in Stockholm behaves with a focus on the larger station Stockholm Odenplan and the smaller station Årstaberg. The duration of the dwell time compared to the stations planned dwell time was analyzed with manual measurements on the stations. The dwell time was analyzed both during and after rush hours. Possible reasons for the dwell time’s length were also analyzed and a potential factor that was in focus was the impact of the removal of train conductors. Train conductors in Stockholm’s rail system are responsible for monitoring the boarding and closing the train’s doors after it is finished. They began to dismantle from the trains Mars 2023 due to efficiency reasons. Half of the trains will run with a train conductor until autumn 2023, where they will disappear entirely. The train drivers will afterwards monitor the travelers with cameras instead. The commuter trains in Stockholm have three routes between Bålsta and Nynäshamn, Uppsala/Märsta and Södertälje and Södertälje and Gnesta. Factors considered when planning their timetables are the system’s capacity, how long the train should wait at a station and how long it takes to drive between stations. 94 % of the trains run on time in the system according to the operator MTR. The analyzed stations Stockholm Odenplan and Årstaberg are in Stockholm and have their separate conditions. Stockholm Odenplan is the second to largest station in the system and is in a central part of the city. The station is underground, and the rails are separated from the platform with platform doors. The doors are shown to cause delays for the dwell time as they are slow. Årstaberg has considerably fewer travelers than Stockholm Odenplan and is in the south parts of the city. The station is over the ground and has no platform doors. There are many theories about the causes behind a train’s dwell time based on the behavior of the passengers. They vary from where they are waiting on the platform, how they are queueing during boarding and the behavior during the boarding. The study shows that the dwell time in Årstaberg stays under its planned 42 seconds, but it is six seconds too long from its planned 60 seconds in Stockholm Odenplan. The dwell time increases during rush hour in Årstaberg and decreases outside of it, while Stockholm Odenplan seems to be largely unaffected by rush hours. Trains with train conductors seem to have a lower dwell time than those without them. The boarding has a shorter duration with train conductors, which shows that they are more efficient than the train drivers using cameras to monitor the boarding. However, it does take a little longer for the train to depart after the boarding is finished when they have a train conductor. Factors causing the dwell time are believed to be related to the flow of passengers and the design of the stations. The platform doors are believed to increase the dwell time in Stockholm Odenplan. Meanwhile, the protection from the weather and the location of the entrance in Årstaberg might impact its dwell time. When the number of passengers increases will the boarding take longer. The boarding will also be concentrated on a few doors in Årstaberg depending on the weather or if the trains are short. The dwell time should be analyzed further for a longer period and during more hours of the day. More stations in Stockholm’s rail system should be analyzed too.