At first I thought these were traffic helicopters in the night sky along the I5 corridor, from the I90 overpass up to Northgate, as they had red, white & blue blinking lights, that appeared to be attached to the underside of an object (the object from a distance reminded me of image of the TV version of Starship Enterprise, but when our car came closer to being under one of them, I was unable to determine the shape of the object), but they appeared to be unmoving. There were a succession of them intermittently placed in a line along the east side of I5. They were too high to be a projection image or attached to a crane (and too high to be attached to a crane)