One type of improvement in public transport is to increase the speed of buses and improve regularity. In congested areas, speed and regularity may be improved through the implementation of measures such as bus lanes, signal priority at traffic lights, a reduction in the number of bus stops, and the re-designing of crossroads, etc., measures that are often framed within the term “bus priority measures”.

In the Scandinavian context the responsibility for implementing priority measures is shared between different actors. In the context of procured public transport the regional public transport authorities (PTA's) and commercial operators are important actors. If bus services operate on roads where the state is infrastructure holder, the national road administrations are also involved (the Swedish Transport Administration, and the Danish Road Directorate). However, the municipal level plays a key role, because they manage the infrastructure for large parts of the urban road network, where the majority of bus travel occurs. Based on this, the purpose of this study is to investigate what causes the Scandinavian capitals, Stockholm in Sweden and Copenhagen in Denmark to prioritise investments in bus priority measures in their road networks. Given the lack of previous research on implementing bus priority measures in the Scandinavian context, we apply a broad, exploratory approach, which means that we are open to explanations both concerning why the cities invest, but also to the challenges associated with implementing bus priority measures. So, the research question is: Which factors promote or prevent municipal investments in bus priority measures?