Three lights in the shape of a triangle.

I was looking at this web sight for the first time and saw an event entered 5/1/2005 that must be the same event that I experienced.  The writer dated the event 5/12/1980 but said he wasn't sure.  I think the event was approximately September of 1978 or 1979.  I was 16 or 17 and driving home from work on interstate 70.  I was headed east from Indianapolis to Greenfield.  
I would say somewhere between the Mt. Comfort Rd. exit and the Greenfield exit, I saw 3 lights in a triangular shape.  The lights were primarily white but I do remember some occasional red and blue.  It would have been around 9:15 based on where I was on my trip home.  The lights moved in relation to each other and formed different sizes of the same triangle. I exited interstate 70 at Greenfield and turned north on highway 9.  I then went approximately 1 mile until I reached 300 north and turned west. (I was still headed home)  Very shortly after I turned onto 300 north, I could see something above me.  I have always described it as a "density".  It was too close above me to make out a shape.  When I looked up, it was big enough that I couldn't see sky on any side of the object.  I have also always said it was probably bigger that two 2 story houses.  I have also said it would be like standing under a large passenger jet, that is on the ground, and looking up.  You could just see the underneath.  I couldn't see the lights at that time and I could not make out the color of the object, just that there was something above me. There was no sound. I am guessing this lasted for just a few seconds until I drove past it.  I went home and made it by my normal time which was approximately 9:30.  I told my parents and they could tell I was visibly excited.  The next morning, I was sitting in my high school home room and they came over the intercom and said the National Enquirer was in the office and wanted to interview anyone having seen a UFO.  I did not go because I was too embarrassed to get up in front of the home room.  I do not know if anybody went.  That evening, the Greenfield Daily Reporter ran a front page article.  In that article, it reported finding markings in a field.  These markings were found somewhere on the opposite side of highway 9 than I had turned.  I turned to the west of 9 and these were found on the east of 9 and at about the same area as 300 north.  I feel it must have been headed east when I saw it.  I match my dates due to where I was working.  I really felt it was in the fall because of feeling new in the home room class.  I did go back to the Hancock County Library a couple of years ago and tried to find the paper.  I was unable to find any article, but I did concentrate on the fall only.  I will make an attempt to go back soon and start checking all of 1978 and 1979.  I will also check to make sure that all of the papers are there.
Witness indicates that the date of the event is approximate.  PD