Wow this is a weird one....

Have you had the control arms checked as teamlegacy said?

Is there a steady wobble coming from the front of the car?

The cement lines in the freeway makes me wonder so please humor my questions.

How long ago did you lower it?
What size rim and tire setup do you have and how long ago were they put on?
Is this your first time driving a car with this setup?

Reason I ask is because it kind of sounds like maybe you aren't used to the difference in how the car runs once its lowered and different wheels because the contact patch is different.

Sounds odd but when you throw 17s on a car it will drive very different than it did at stock. The cement grooves you are talking about will play hell with your driving as well.