My friend Deb and I were driving back to Pennsylvania after having visited my mother in Canada. We were heading south about 1:30 am when we saw a flashing light through the trees. When we got closer and there were no trees between us and it we could see that it was a triangle and the whole bottom of it was flashing in intensity, but it would never go dark, it would just get intensely bright and then less bright. I wanted to stop and take a picture or a movie, but my friend was afraid. She said she didn't want to be abducted she had to go to work in the morning. It was just over the trees to the right when we passed it. When we did it started to move off to the north slowly. I could see its flashing in the rear while I drove and my friend watched it for quite a while as we moved away.