The Italian Constitutional Court declares illegitimate a national rule on the car rental service with driver due to lack of proportionality with the national and European principles of the market and competition. The Constitutional Court ruling on the car rental service with driver represents an important analytical perspective for confirmation of particular legislative choices for administrative regulation, where competition is regulated according to social utility. The sentence of the constitutional court is an input for the future legislator to intervene on new market phenomena that risk compromising the correct functionality of this transport segment with a strong social impact.