Under the 1925 numbering system, PA 103 was a spur route of the original PA 3, the William Penn Highway.
ˌʌndɚ ðə nˈaɪntiːnhˈʌndɹɪd twˈɛnti fˈaɪv nˈʌmbɚɹɪŋ sˈɪstəm, pˌiːˈeɪ wˈʌnhˈʌndɹɪd θɹˈiː wʌzɐ spˈɜː ɹˈaʊt ʌvðɪ ɚɹˈɪdʒɪnəl pˌiːˈeɪ θɹˈiː, ðə wˈɪljəm pˈɛn hˈaɪweɪ.