ðə fˈɜːst ˌɪntɹədˈʌkʃən ʌv ɹˈaʊt bɹˈændᵻd vˈiəkəlz kˈeɪm ɪn tˈuː θˈaʊzənd sˈɪks, wɪððə ɹᵻnˈeɪmɪŋ ʌvðɪ ˈoʊld ˈaʊɾɚ sˈɜːkəl sˈɜːvɪs ðə ˌoʊsˈiː.
The first introduction of route branded vehicles came in 2006, with the renaming of the old outer circle service the 'OC'.