My mom, I, and my kids-girl 7, boy 5, went on a car trip to my maternal grandmother's home east and south outside of Riverside, Ia. It was easier to travel long distances with small children at night, so we started around 8 or 8:30pm North on a 2-lane highway from rural Iowa around Shenandoah up to just outside Atlanta where you hit I-70 East to Iowa City. When we came to about 15 miles outside of Griswold on the 2-laner, Mom and I saw a strange light above where Griswold grain elevator is. It looked like a pulsating star, only too low to be a star. We asked each other if we had heard of a new business in Griswold that would have or need a light to worn aircraft of it's existence. Neither of us had, and said we would ask around when we got home. The pulsating got brighter and it seemed lower as we approached the town. But once through the town the light was no longer visiable. So we talk about it, wondering what kind of light it was for the rest of the drive. Five days later, we again are on the same trip in reverse and when we got to the Atlanta turnoff I laughingly said "Do you think our friends will be waiting for us at Griswold?". My mom laughed and said it was probably an explosives plant so of course it would be there. But it was waiting for us just after we turned onto the 2-lane state highway outside of Atlanta; first high above like before, than an instant later was at the top of the fence posts on the passenger side of the car. If we went up a hill, or around a bend, or whatever it went up the hill, or around the bent keeping level with the car's passenger's side window and the car top. We got spooked after about 30 minutes of this. I said we should stop and see who they were and what they wanted. My mom said "DRIVE". This conversation happened repeatedly over the next 5 hours. The craft/light started as a dull black presence which in the ??center started a light (glowing pulsing and then erupted) that elongated both up and down, the length and height of the craft/light every few seconds, then the light would kind of collapse in on itself back into the center. It would be dark for just a second or so at most, and then the process would start again. This happened the entire time. But it did not light up the fields under or around, or the fence itself. You saw those, what little you could see at night, from the headlights of my car. There was no other traffic on that highway at night. It seemed from the shape and size of the light to be 4-5 times as long as my Datsun station wagon and so tall I in the driver's seat could not see the top even looking through the windshield. It was darker and seemed denser than the surrounding area. You felt like "they" were watching and listening because when getting to within 3 miles of home I said "If they follow us home, do we have enough food to feed these people??" We went around the last bend in the road before home they just were gone. There one minute and gone the next.