Boulevardisation as a tool to reduce barrier effects from transport infrastructure: a case study of the planned Dag Hammarskjöld boulevard

Abstract

Dag Hammarskjöldsleden is a multi-lane freeway stretching from Linnéplatsen to the interchange Jänrbrottsmotet in Gothenburg, Sweden. The city of Gothenburg wants to rebuild it into a boulevard, with one of the purposes to reduce barrier effects, hence making it a more attractive area to live in. Reduced accessibility and increased travel times to services and workplaces are examples of direct barrier effects. Job van Eldijk has created a conceptual model describing these barrier effects. In this thesis, the suitability of boulevardisation of transport infrastructure as a means to reduce barrier effects for pedestrians and cyclists is studied, using the Dag Hammarskjöld boulevard project as a case study. A geographic model of the area around Dag Hammarskjöldsleden was created with GIS and quantitative indicators were used to assess the extent of barrier effects under different scenarios. Four scenarios were created with different street networks, residential development and distribution of facilities: 0 - how the area looks today, A - how the area would look with a boulevard design only, B - how the area will look with the planned new urban development only, and C - how the area would look with both the future urban development and a boulevard design, which also represents the design the municipality proposes. Five barrier effects indicators were calculated for each scenario: choice of a facility of given category, facilities’ catchment area, proximity to a facility category, Betweenness, and Detour factor. By comparing the indicator analyses for scenarios 0 & A, it can be concluded that the boulevardisation of Dag Hammarskjöldsleden, without further urban development, would have limited effect on the barrier effects, due to the lack of demand for crossing the road today because of the absence of activities on the east side. The comparisons between scenario B & C, which included increased urban development, indicates that the boulevardisation would have a significant effect on the southern and middle sections of the studied area. It is especially addition of new crossing facilities that improves the accessibility in these areas, hence reducing the barrier effects.