I was driving northbound on I-95 between the Massachusetts border and the Hampton Tolls just south of Seabrook, New Hampshire at a speed of ~75 MPH. An object entered my field of vision at approximately 2 o'clock (NNE) at 60 degrees above the horizon. The silvery blue glowing object travelled at a very low rate of speed in the same direction as I was driving for a few seconds. The object flew at a speed slightly greater than my vehicle, around 100 MPH. I estimated the size of the this object to be the size of a pencil eraser held at arm's length. Then the object accelerated and changed direction to the NNW across the eight lane highway. Then the object simply vanished. The amount of time that had passed was approximately 6 - 7 seconds. This location of the highway is in close proximity to the Seabrook Nuclear Power Station.