ðə sˈɑːɡnsvæn lˈaɪn wʌz sᵻlˈɛktᵻd æz ðə fˈɜːst lˈaɪn təbi ʌpɡɹˈeɪdᵻd, sˌoʊ ðə tˈuː sˈɪstəmz wʊd bɪkˌʌm kəmpˈæɾᵻbəl.
The Sognsvann Line was selected as the first line to be upgraded, so the two systems would become compatible.