Welcome to the forum Blazing. I'm guessing what you're experiencing is the wide front tires are "hunting" the "ruts" in the road left by 1000's of Trucks.
If you notice it more on blacktop roads, that's probably it.
Being from Seattle, I'm going to assume many of your concrete roads have "rain grooves", and I agree with JimJet those will have an effect on our cars too. (My old C4 Vettes were very susceptible to minor irregularities in the road).
Try to locate a really smooth blacktop "asphalt" road that doesn't get much "heavy" traffic and see if you notice anything unusual. I'm going to predict smooth sailing.
Enjoy