Complex sentence: Denton County has bus service limited to Denton and Lewisville owned by the Denton County Transportation Authority, although a light rail line is planning that would parallel I-35 to connect Carrollton, Lewisville, Lake Dallas, and Denton.
Split into simpler sentences: Denton County has bus service limited to Denton and Lewisville owned by the Denton County Transportation Authority. A light rail line is in planning that would parallel I-35 to connect Carrollton, Lewisville, Lake Dallas, and Denton.