Key legal question
Whether Art. 4(1)(a) of the Geneva law banning alcohol sales in stations-service and accessory shops violates federal supremacy under Art. 49 Cst.
Extracted holding
No. The cantonal ban complements, rather than contradicts, federal alcohol and health rules and remains within residual cantonal competence.
Extracted reasoning
Federal law regulates alcohol sales only selectively; the canton may adopt additional measures pursuing road safety and alcohol-prevention objectives, especially where federal law is not exhaustive.