Port Jefferson Branch service (as distinct from the piece of railroad called the Port Jefferson Branch) extends east from Floral Park, where the Hempstead Branch separates from the Main Line. The line west of Huntington is electrified and double tracked. Electrification extends to a point east of Huntington before Greenlawn station on a layup track for electric trains. East of there the line is single track with passing sidings at Greenlawn, east of East Northport, Kings Park, Smithtown and Stony Brook allowing trains traveling in opposite directions to pass each other.