Complex sentence: Trains generally operate between Boston, Massachusetts, and Washington, D.C., with extra service between New York City and Washington with branches going to Springfield, Massachusetts and Richmond, Newport News and Lynchburg, Virginia.
Split into simpler sentences: Trains generally operate between Boston, Massachusetts, and Washington, D.C., with extra service between New York City and Washington. Extensions and branches extend service to Springfield, Massachusetts and Richmond, Newport News and Lynchburg, Virginia.