Lowering speed limits is increasingly acknowledged as a key measure to foster resilient streets, improve urban liveability, and reduce the environmental impacts of motorized traffic. However, little research has sought to assess street speed limits through the lens of urban equity. Based on OpenStreetMap data, the present paper explores the spatial distribution of street speed limits across different neighbourhoods in Barcelona through various aggregate indicators. My results show that average speed limits vary significantly between neighbourhoods, reflecting the existence of spatial inequities regarding the negative externalities of automobility. Although my analysis shows that neighbourhoods with higher speed limits tend to have higher incomes and motorization rates, it also draws a ention to outlier neighbourhoods which combine high traffic speeds and low motorization rates. From a distributive justice perspective, I argue that these outlier neighbourhoods should constitute a priority for traffic calming and speed reduction strategies. Finally, I suggest that the proposed speed limit indicators could easily be replicated in other cities, thereby enabling cross-city comparisons and providing a useful tool for research, policy and advocacy.