Wikipedia:WikiProject Canada Roads/Prince Edward Island/Notes on numbering and notability

The network is way too dense for every route to be notable. Three digit routes are essentially numbered by county: Prince County 1, Queens County 2, and Kings County 3.

Two-digit routes are:
 * Route 1, Borden to Wood Islands
 * Route 1A, Albany to Travellers Rest, formerly also to St. Eleanors via Route 11
 * Route 1A, Cross Roads to Mount Mellick
 * Route 2, Tignish to Souris
 * Route 3, Cherry Valley to Georgetown
 * Route 4, Wood Islands to Dingwells Mills
 * Route 5, Mount Albion to Cardigan; used to extend to Dingwells Mills via Route 4
 * Route 6, Kensington to Bedford
 * Route 7, Milton to Oyster Bed Bridge
 * Route 8, Ross Corner to New London
 * Route 9, Long Creek to Brookfield
 * Route 10, Central Bedeque to Tryon
 * Route 11, Inverness to Reads Corner and St. Eleanors
 * Route 12, North Cape to Miscouche
 * Route 13, Crapaud to Cavendish
 * Route 14, North Cape to Carleton
 * Route 15, Charlottetown to Brackley Beach
 * Route 16, St. Peters to Souris
 * Route 16A, Lakeville to South Lake
 * Route 17, Murray River to Montague
 * Route 17A, Cambridge to Sturgeon
 * Route 18, High Bank to Murray River
 * Route 18A, White Sands to Murray Harbour
 * Route 19, DeSable to Cornwall
 * Route 19A, Canoe Cove to New Dominion
 * Route 20, Kensington to New London
 * Route 21, Southport to St. Patrick Road
 * Route 22, Mount Stewart to Victoria Cross
 * Route 23, Orwell to Wood Islands
 * Route 24, Vernon River to Murray River
 * Route 25, Marshfield to Stanhope
 * Route 25A, Covehead Road to West Covehead

Three-digit routes that look notable are: Arterials and collectors are listed at.
 * Route 107, Reads Corner to Clinton: collector southwest of Norboro
 * Route 121, Summerside to Sherbrooke: thick line on the official map
 * Route 122, St. Nicholas to Southwest Lot 16: collector
 * Route 124, Abram-Village to Wellington: thick line on the official map; collector
 * Route 131, Wellington to Birch Hill: collector north of MacDougall
 * Route 133, Mount Pleasant to Ellerslie: thick line on the official map
 * Route 142, West Cape to Roxbury: thick line on the official map; very thick (arterial) beyond O'Leary (to Woodstock)
 * Route 150, Campbellton to Alberton: arterial and collector east of Elmsdale
 * Route 152, Ebbsfleet to Northport: thick line on the official map; partly collector
 * Route 153, Montrose to Christopher Cross: thick line on the official map (to Tignish); collector
 * Route 167, MacDougall to Tyne Valley: collector
 * Route 178, Northam to Tyne Valley: thick line on the official map, along with a bit of Route 132 from Route 2
 * Route 225, Middleton to Warren Grove: thick line on the official map, along with a bit of Route 248 to North River; both collectors
 * Route 258, New Glasgow to Rusticoville: thick line on the official map; collector
 * Route 313, Cardigan to Greenwich: thick line on the official map; collector south of Cardross
 * Route 315, Wood Islands to Montague: thick line on the official map; collector
 * Route 321, Roseneath to Morell: collector north of Cardross

Other notable roads are:
 * Charlottetown Perimeter Highway, as well as Upton Drive and Riverside Drive connecting each end to Route 1: arterial

The following one- and two-digit routes are local (not arterials or collectors):
 * Route 1A (east segment)
 * Route 5
 * Route 8 north of Summerfield
 * Route 9
 * Route 10
 * Route 11 west of Miscouche (partly unpaved)
 * Route 12: north of Alberton, Portage to Ellerslie, Tyne Valley to MacDougal, Southwest Lot 16 to Miscouche
 * Route 14 (partly unpaved?)
 * Route 16 north/west of South Lake
 * Route 17
 * Route 17A
 * Route 18A
 * Route 19: south/west of New Dominion
 * Route 19A
 * Route 20: east of Malpeque
 * Route 21: east of Pisquid (partly unpaved)
 * Route 22: south of New Perth
 * Route 25A

There are also a few scenic heritage roads.