The University of Delaware in Newark, Delaware is conveniently located between Baltimore and Philadelphia along the I-95 corridor. Newark is ~2h drive from Washington, DC; 1.5h drive from Baltimore, and 1h drive from Philadelphia.
Newark is serviced by two international airports. Philadelphia International Airport (PHL), 60 km to the northeast and Baltimore-Washington International (BWI), 105 km to the southwest.
The best option for travel between the airports and Newark is the Delaware Express Shuttle. Shared van service from PHL to Newark is ~$42 (plus tip). Two or more additional passengers are half price each (~$21). Minimum cost for shuttle service from BWI is ~$129 (inc. tip), but this price covers up to 4 passengers.
Newark is also located along the Northeast Corridor passenger rail line. Amtrak passenger rail service runs from Washington DC to Boston, MA. The closest regular service Amtrak station to Newark is Wilmington, Delaware. Amtrak connects Delaware to New York LaGuardia International airport (~230 km from Newark). Taxi service is available from Wilmington to Newark.