First things first: a "statute of limitations" is a state law that puts a time limit on your ability to file a lawsuit in civil court. That time limit is almost always set in terms of years, and the specific deadlines will vary depending on what kind of lawsuit you want to file.
The most important thing to know about these laws is that if the filing deadline has passed, but you try to get the case started anyway, the defendant (that's the person you're trying to sue) will almost certainly bring that fact to the court's attention. From there, the court is very likely to grant a motion to dismiss, and that will be the end of your case, unless one of a handful of rare exceptions applies, extending the deadline.
Now, onto the specifics. In New Jersey, the statute of limitations deadline for most car accident lawsuits is the same as the larger one that applies to any kind of personal injury case. New Jersey Statutes section 2A:14-2 says: "Every action at law for an injury to the person caused by the wrongful act, neglect or default of any person within this State shall be commenced within two years next after the cause of any such action shall have accrued."
In plain English, that means any injury claim filed by a driver, passenger, motorcycle rider, bicyclist, or pedestrian must be filed within two years of the underlying car accident. (Note: The success or failure of the case will most likely turn on whether you can prove that someone's negligence caused the crash. Learn more about Car Accidents Caused by Negligence.)
A two-year deadline also applies if someone died as a result of the accident, and a family member or other representative wants to file a wrongful death claim. That statute of limitations can be found at New Jersey Statutes section 2A:31-3, and keep in mind that the "clock" starts running on the date of the accident victim's death, which could be later than the date of the accident itself. (Learn more about New Jersey Wrongful Death Lawsuits).
From a strategy standpoint, it's always a good idea to leave yourself plenty of time to file a lawsuit if you need to, even if you're confident your case will be resolved via the car insurance claim process. If the filing deadline is looming, it's probably time to talk to an experienced New Jersey car accident attorney to make sure your legal rights are protected.