I, literally, just had this same problem today. I just paid 500 dollars to have my front wheel bearings replaced. I decided to hit the highway, today, to test it all out. Once I hit a certain part of the highway (with the grooves in it). The rear end of my car started to wobble back and forth so much that it made me very nervous. I have never experienced this before. I said. “Screw it. I guess my car isn’t highway ready yet” and I turned around to head back home. But once I got off of that grooved section of the highway… It stopped. It was fine. It was normal. What gives? Why did it feel so dangerous on that, particular, part of the highway?
It’s called groove wander and it is caused by the ribs in the tires following the grooves in the pavement.
Because there is no standard spacing for pavement grooves, occasionally a specific size of tire will have 2 or more of the ribs in the tread pattern line up with those pavement grooves. It is confined to that specific size/make/model tire and that particular stretch of highway (and any others cut by the same machine.)
Aside from avoid those stretches of highway, the only fix is to change the tires to another size or model.
Oh and to be helpful, be sure to tell the tire manufacturer (on their 800 number) that you had this problem. They can add it to their list and prevent other tire models from having the same problem.