European Union – Concept of state aid. The Court of Justice of the European Union ruled that the practice in London, England, of permitting Black Cabs to use bus lanes on public roads during the hours when the traffic restrictions relating to those lanes were operational, while prohibiting minicabs from using those lanes, except in order to pick up or set down passengers who had pre-booked such vehicles, could be such as to affect trade between member states within the meaning of art 107(1) of the Treaty on the Functioning of the European Union, which it was for the referring court to determine.