It's a State Right!

The Ledger is reporting today that a Federal Appeals Court has struck down a 1999 Department of Transportation regulation keeping large trucks off of secondary highways. This requlation was passed, because at the time there were a number of serious truck accidents on secondary roads around the state and local officials were complaining about the large truck traffic on local roads. It seems to me that if a State wants to direct where trucks and what size trucks can be on a road it is their right. Where in the constitution does it give congress the right to control interstate commerece. It must be right next to the mythical right to privacy.