I agree with you on the amount of debris along I-35... sand, gravel, broken glass, pieces of tires, etc. My cars have really taken a beating over the years. You would think the cities along the I-35 corridor would have a street sweeper clear the shoulders once in awhile to keep up a good appearance, but they don't since it's a state-owned highway.

I'll keep an eye out for you. Have a good day!