The environmental association Zero has called for the Lisbon Metro to open earlier at 05:30, alongside increased service frequency and station improvements, to provide a viable alternative to private cars amid soaring fuel costs. The association argues that the current 06:30 opening time fails to serve essential workers starting early shifts and highlights operational inefficiencies on the Yellow Line, particularly between Campo Grande and Odivelas. Zero acknowledges staffing and infrastructure constraints but insists that management must re-evaluate priorities to ensure a reliable public transport service.