The LI ITS network of highways is important to Long Islanders for travel throughout Long Island. Typical trip purposes include the journey to work as well as shopping, recreational and commercial trips that are not local to the travelers' immediate area. The network supports longer trips passing through all or most of the area. Since many of the trips, and most of the congestion are in the east-west direction, the LI ITS network emphasizes trips in that direction.

Included Roadways

• I-495 (Long Island Expressway), Northern State Parkway and Southern State Parkway are the principal east-west routes in the LI ITS network.
• The Meadowbrook State Parkway, Wantagh State Parkway, and Route 135 (Seaford-Oyster Bay Expressway) constitute the principal north-south routes — as far south as Route 27 (Sunrise Highway) — along with the Sunken Meadow State Parkway /Sagtikos State Parkway from Route 25A.
• The southern portions of the Meadowbrook State Parkway and Wantagh State Parkway, Robert Moses Causeway and Ocean Parkway are included since they are commuter routes as well as major recreational travel routes and support the "Reach the Beach" travel advisory program.
• The Bethpage State Parkway is heavily used during the weekdays by traffic traveling to avoid congestion of the Southern State Parkway.

Nassau County — At Grade Arterials

Route 27 (Sunrise Highway)
Carman Mill Road/Merrick Road
Route 25 (Jericho Turnpike)
Hillside Avenue
Union Turnpike
Route 24 (Hempstead Turnpike)/Fulton Street
Middle Neck Road/Port Washington Boulevard
Front Street
Jerusalem Avenue
Newbridge Road
Hicksville Road
Nassau Expressway
Fulton Street
Ocean Parkway
Peninsula Boulevard
Corona Avenue/Franklin Avenue (Valley Stream)
Ocean Avenue (Malverne)
Service Roads on I-495 (Long Island Expressway)

Suffolk County — At Grade Arterials

Route 27 (Sunrise Highway)
Merrick Road/Montauk Highway
Route 25 (Jericho Turnpike)
Route 454 (Veterans Memorial Highway)
Route 347 (Nesconset - Port Jefferson Highway)
Route 231 (Deer Park Avenue)
Medford Road/Patchogue Road/Port Jefferson Road
Harbor Road/Ocean Parkway
Suffolk Avenue
Lakeland Avenue/Ocean Avenue
Nichols Road
Ocean Avenue/Patchogue-Mt. Sinai Road
Service Roads on Route 27 (Sunrise Highway)
Service Roads on I-495 (Long Island Expressway)
Babylon - Northport & Deer Park Spur
Carleton Avenue/Wheelers Road