Overview
Route 25A — officially the North Shore Road — is Long Island’s most scenic highway, running 72 miles from the Nassau/Queens border through the coastal communities of the North Shore to Calverton in eastern Suffolk County. Unlike the high-speed expressways and parkways that dominate Long Island’s highway network, Route 25A is predominantly a two-lane undivided road passing through historic village centers, past harbors and bays, and through the rolling North Shore landscape that has attracted wealthy residents since the Gilded Age.
The road follows the historical northern spine of Long Island, connecting communities that were among the island’s earliest European settlements. Great Neck, Oyster Bay (home of Theodore Roosevelt’s Sagamore Hill), Cold Spring Harbor, Huntington, Northport, Stony Brook (site of one of the State University of New York’s flagship campuses), and Port Jefferson are all on or directly accessible from Route 25A, giving the road a historic and cultural density that few Long Island roads can match.
Cold Spring Harbor deserves particular mention: the stretch of Route 25A hugging the western shore of Cold Spring Harbor is one of the most photographically striking sections of any Long Island road, with the road carved into the hillside above the harbor with almost no shoulder width. The Cold Spring Harbor Laboratory — where James Watson and Francis Crick’s DNA research was extended and where multiple Nobel Prize winners have worked — is located directly on Route 25A.
The road’s scenic character comes with safety trade-offs. Two-lane sections through villages have no room for error, and the speed differential between through traffic and local turning movements creates frequent conflicts. The North Shore’s hilly terrain, combined with winter ice and limited plowing priority compared to expressways, makes Route 25A particularly hazardous in cold weather.
Dangerous Sections
Cold Spring Harbor narrow section (Nassau/Suffolk border): This two-lane section is carved into the hillside above Cold Spring Harbor with minimal shoulder. Any disabled vehicle creates an immediate secondary crash risk. The grade and the harbor views distract drivers. Ice accumulates here before it does on flatter road sections.
Oyster Bay village approach: The approach to Oyster Bay from the west involves a significant grade change and a sharp curve near the village center. The historical road alignment was not designed for modern traffic volumes.
Port Jefferson village approach (Setauket / Port Jefferson): The descent into Port Jefferson from the Setauket area includes steep grades that are hazardous in snow and ice, and the village center’s narrow streets and ferry traffic create significant congestion during summer months.
Towns Along This Route
Current Conditions
Check back for real-time conditions.
Recent Incidents
No recent incidents to display.
Accident Statistics
Route 25A crash data show the two-lane sections consistently outperforming the divided sections in per-mile crash rates. Winter months see a disproportionate share of run-off-road and head-on crashes on the narrow sections, particularly after snow and ice events. Head-on collisions and off-road excursions dominate the crash profile on two-lane rural stretches, with cyclist and equestrian incidents adding to the safety picture on certain sections near Cold Spring Harbor and Oyster Bay. Night crashes on the unlit rural sections are disproportionately severe, as the absence of street lighting removes the visual margin that catches driver errors before they become crashes.