Why do Italian road signs use the infinitive tense and not the imperative?

Question

Why do Italian road signs use the infinitive tense in their warning, while, for example, those in English use the imperative?> Turn off lights> Spegnere le luci (and not "Spegnete le luci" or "Spegni le luci") Or, maybe, is there a rule that says that the infinitive tense can be work as an imperative? If so, can anyone suggest some cases in which that rule is used in everyday speech?

Answer 1

one reason could be that in Italian we have different forms of imperative: SPEGNI, SPEGNETE, SPENGANO, SPENGA, depending on which form is used, formal, informal, singular, plural, in english there is only one form so no confusion.