Tramlining in Audi A4

On one of my local roads, the Audi has a strange feeling that runs through the chassis.. well I thought it was the chassis.. then I thought it was the seat.. it is sort of a wandering / sloppy feel. However when talking to my father in law, he asked me how the car felt with the 245/45 tyres, as his Saab tramlined with low profile tyres. Then it connected, the sensation I was getting on this road was tramlining - there is some road works and the car basically wants to follow these road imperfections like a map.. the only other car I had that did this was my Honda S2000 which would tramline a bit under braking with grooved roads near stop signs.