As a hub of commercial aviation, Long Island contains two of the New York City metropolitan area's three busiest airports, JFK International Airport and LaGuardia Airport, in addition to Islip MacArthur Airport; as well as two major air traffic control radar facilities, the New York TRACON and the New York ARTCC. Nine bridges and thirteen tunnels (including railroad tunnels) connect Brooklyn and Queens to the three other boroughs of New York City. Ferries connect Suffolk County northward across Long Island Sound to the state of Connecticut. The Long Island Rail Road is the busiest commuter railroad in North America and operates 24/7. Nassau County high school students often feature prominently as winners of the Intel International Science and Engineering Fair and similar STEM-based academic awards. Biotechnology companies and scientific research play a significant role in Long Island's economy, including research facilities at Brookhaven National Laboratory, Cold Spring Harbor Laboratory, Plum Island Animal Disease Center, State University of New York at Stony Brook, the New York University Tandon School of Engineering, the City University of New York, and Hofstra Northwell School of Medicine.