Accessibility is an important factor in the development of land-use patterns and urban settlements, and these two components are considered linked close together. With the increasing attention payed to reduction of CO2 emissions, focus has been turned towards increased accessibility to public transportation. The work conducted in this study proposes a simplistic raster based model of accessibility to workplaces based on the public transportation services. The raster GIS based approach was chosen due to the need to combine this model with a raster based land-use simulation framework, where simulations of future urban development could be modelled. It has been shown that the proposed GIS model developed is suitable for representing the spatial difference in terms of accessibility for commuters by public transport within the study area. Clear differences between the Copenhagen Metropolitan area and the outskirts of the region can be seen, and are very much in line with statistics on commuting activities for the municipalities involved.