Expanding urban green space with superblocks

The Barcelona superblock is an urban neighbourhood transformation strategy, with which car-based traffic is redirected away from streets that are inside a 3 × 3 urban block configuration. This urban design concept promises opportunities for alternative street use such as the transformation of street space into urban green space. The potential to foster urban green space due to superblock design is however unclear, particularly outside of the original Barcelonan context. Concerning urban densification, fostering urban green space is particularly relevant to achieving dense and green cities. In this study, potential superblocks are identified in all major Swiss cities and the current urban green space is quantified. This analysis reveals distinct differences of superblock opportunities and urban green space between different cities and allows pinpointing opportunities for expanding urban green space. Considering the nine largest Swiss cities, between 3% and 18% of the current street network was simulated to be potentially suitable for superblock implementation to transform the streetscape and increase urban green space. The variation of current urban green space coverage across all potential individual superblock sites that have high urban density ranges considerably from a few percentages to above 30%. The presented results allow the exploration of urban green space opportunities at street and block-level arising from superblocks in Switzerland. For example, when considering a citywide superblock implementation scenario, the potential street area is relatively high for Basel whilst at the same time showing relatively low current availability of urban green space. For creating detailed design or transformation strategies based on the explored superblock sites, more integrated analysis to evaluate potential benefits as well as disservices of such urban transformation is required.