Complex sentence: Travelling between the two segments will require a combination of Appalachian Corridor G (US 119), I-79, and Appalachian Corridor H (US 48), but neither US 119 nor US 48 are built to interstate standards.
Split into simpler sentences: Travelling between the two segments will require a combination of Appalachian Corridor G (US 119), I-79, and Appalachian Corridor H (US 48). Neither US 119 nor US 48 are built to interstate standards.