FARMINGVILLE, N.Y. (PIX11) – A driver slashed the throat of another vehicle’s passenger in a Long Island road rage incident Wednesday night, leaving a 4-inch gash on the victim’s neck, authorities said.

A woman was driving a BMW with two passengers, including the victim, on the Long Island Expressway around 10:15 p.m. when she got into a road rage incident with the assailant near Exit 63, police said.

Once both drivers had pulled off the LIE and were waiting for a light at Express Drive North and North Ocean Avenue in Farmingville, the man behind the wheel of the other car got out and tried to open the front driver’s side door of the BMW, officials said.

Finding the door locked, he then tried to grab the woman through an open rear window, but a male passenger grabbed his arm, police said. The two wrestled, and the attacker sliced the victim’s neck, leaving a four-inch gash, authorities said.

The BMW’s driver, panicked, drove through a red light to escape and headed to a nearby CityMD office for help, police said. The injured passenger was treated at a local hospital, with officials describing his wounds as non-life-threatening.

The assailant fled in his car, described by authorities as a royal blue 4-door sedan — possibly a Mazda 3 or 6 — with yellow New York plates, police said.

Detectives are asking anyone with information on this incident to call the Sixth Squad at 631-854-8652 or Crime Stoppers at 1-800-220-TIPS. All calls will be kept confidential.