Long Island Expressway Exit 56 — NY 111

Exit 56 sits along the Long Island Expressway (I-495), a 66-mile interstate corridor carrying more than 200,000 vehicles a day , serving NY 111 near Hauppauge / Smithtown. We haven't yet logged a reported crash at this specific interchange — but on Long Island Expressway as a whole, rear-end collisions during the AM peak when westbound traffic stacks dominate the crash record. Any incidents we track at Exit 56 will appear below as they're reported.

Risk is highest during weekday 6–10 a.m. westbound and 3–7 p.m. eastbound. Drivers unfamiliar with the interchange geometry — especially those exiting versus those merging on — are disproportionately represented in the crash record.

Know your exit, and commit early. The biggest single contributor to crashes at Long Island Expressway interchanges is late lane changes. If you're taking Exit 56, move to the appropriate lane at least a half-mile in advance; on Long Island Expressway specifically, rear-end collisions during the AM peak when westbound traffic stacks drive most of the collision volume we record.

Mind the merge. Whether you're entering or leaving the mainline, yield to through traffic and match their speed before pulling into the travel lane. Sudden braking in the deceleration lane produces rear-end collisions — the single most common crash type on Long Island Expressway.

If you need to divert. When Long Island Expressway is blocked at or near Exit 56, the most common detour is Northern State Parkway and Jericho Turnpike. Check 511NY for live conditions before choosing an alternate; closures and secondary crashes can cascade quickly in this corridor.

Peak-hour caution. Expect elevated risk during weekday 6–10 a.m. westbound and 3–7 p.m. eastbound. During these windows, leave extra following distance and keep your phone stowed — distracted-driving citations are concentrated at congested interchanges like this one.