At a news briefing Thursday morning, Nassau County authorities said the search will focus on areas that have been inaccessible by foot. Objects were previously spotted there by helicopter.
The FBI said it would supply aircraft with high-tech photo equipment to assist in the search of the vast shoreline. An FBI spokesman said the flights will begin on Friday.
The search follows the discovery of 10 sets of human remains in recent months near the highway. Police suspect some may be victims of a serial killer.
No suspects have been identified.