mˈeɪdʒɚ ɹˈaʊts wɜːɹ ɐsˈaɪnd θɹˈiː ɔːɹ fˈoːɹdˈɪdʒɪt nˈʌmbɚz, wˌaɪl mˈaɪnɚ ɹˈaʊts wɜː ɡˈɪvən fˈaɪvdˈɪdʒɪt nˈʌmbɚz ɪnwˌɪtʃ ðə fˈɜːst tˈuː dˈɪdʒɪts ɹˌɛpɹᵻzˈɛntᵻd ðə kˈaʊnti, ɪn ˌælfəbˈɛɾɪkəl ˈɔːɹdɚ fɹʌm wˈʌn ˈædəmz tə sˈɪksti sˈɪks jˈɔːɹk.
Major routes were assigned three- or four-digit numbers, while minor routes were given five-digit numbers in which the first two digits represented the county, in alphabetical order from 1 (Adams) to 66 (York).