Gothenburg is a city that never stops moving. Hundreds of thousands of trips happen every day on its streets, and the people responsible for planning those streets need to understand exactly what is happening on them. Stadsbyggnadsförvaltningen, the city’s spatial planning authority, had been collecting traffic data for years. They had sensors. They had suppliers. They had a Traffic Catalogue that had technically existed for a long time. What they did not have was a version of that catalogue that anyone could actually rely on.