Resident group specific accessibility analysis and implications for the Great Helsinki Region using Structural Accessibility Layer

- SAL has proven, besides its limitations, a suitable accessibility measure for local urban and transportation planners.
- There are significant differences in potential accessibility between different age group residents in the Helsinki Capital Region.
- Children between 0 and 7 years old and students are the age group with worst quality access to their targeted services.
- Further research including the frequency of use of services is necessary for a fully evaluation of the uneven accessibility in the area.

This research analyses accessibility for different age population groups in the Great Helsinki Region (GHR). After discussing previous approaches done in the GHR, the authors use the Structural Accessibility Layer (SAL) as a tool for accessibility categorization for a grid with 8325 zones. SAL method was applied to assess accessibility categories for specific age population groups and the spatial distribution of the groups was used for identifying potential areas for urban development or requiring additional service allocation. The results for the general map show that 74,52% of residents have access to the services with public transport; however dissimilarities appear when calculating accessibility for specific groups: while 39,6% of pensioners enjoy accessibility by all transport modes, 32,8% and 32,0% of students and children between 0 and 7 years old reside in areas of car-dependent accessibility. The findings highlight the benefits of population group specific accessibility measures. Urban and transport planners of the region have validated the method derivation as a useful and reliable approach for public services planning and accessibility forecasting. Authors propose this accessibility approach for management of public services allocation and further research is indicated.