Kearny is located approximately 6.5 miles from Newark-Liberty Airport and as such, it is not too far from Midtown Manhattan either. Your most convenient option is to take a train to Midtown Manhattan and then transfer on to any one of several public bus routes from here, including the 1, 39, 40 and 43, which will transport you to Newark. From here, you can take a taxi to Kearny, as it is a short ride.
