Passenger traffic for train journeys has been limited in northern Sweden due to the fact that the railway has mainly been used in industrial business. The establishment of Botniabanan enabled passenger traffic by train and created a train connection between the cities in the region. A continuation of Botniabanan quickly began to be planned so that the railway would continue along the Norrland coast, and the so-called Norrbotniabanan came into being. Today, northern Norrland is also facing one of the largest industrial investments in Sweden's history, which will require an increased workforce and supply of skills. In order to meet the demand for labor, Norrbotniabanan can provide a good opportunity for increased work commuting. An efficient and improved transport supply can in turn increase work commuting without people having to move to work. This in turn can create regional enlargement.  The purpose of the study is to investigate and analyze the effects Botniabanan had on commuting and further analyze and compare these with the effects that can be expected to occur with commuting through the establishment of Norrbotniabanan. The study is based on predictions about Norrbotniabanan and whether these can be expected to be achieved. This is then compared with whether the expected effects of Botniabanan were fulfilled. The establishment of Norrbotniabanan is then presented in a context of regional enlargement. The study has been carried out based on a quantitative method by processing quantitative data (register data) as well as carrying out literature studies and content analysis.  The study found that commuting has increased since the establishment of Botniabanan and that commuting mostly increased to Umeå municipality but also to Kramfors, which may be due to the municipality not belonging to Umeå's area of influence. In relation to this, commuting can be expected to increase with the establishment of Norrbotniabanan and in the same way that commuting mainly takes place to the larger municipalities such as Umeå, Luleå and Skellefteå. In order for Norrbotniabanan to achieve a greater increase in commuting than Botniabanan, the travel times need to be well planned. Provided that Norrbotniabanan has taken into account the reasons why the journey times for Botniabanan were not achieved, Norrbotniabanan has a good opportunity for a greater increase in commuting. Botniabanan can be declared to have achieved a regional enlargement, which Norrbotniabanan also makes possible. With the industrial investments in northern Sweden, Norrbotniabanan can create a stronger regional expansion than what Botniabanan did.