Knoxville police are stepping up their enforcement of traffic laws for the holiday.
Tuesday afternoon, more officers began patrolling city streets. They're especially looking for speeders, tailgaters, and anyone driving under the influence. The special enforcement period ends Wednesday night at midnight.
As of Tuesday, state troopers are using a new law that allows them to get a warrant to make suspected drunk drivers give a blood sample.
Anyone pulled over for DUI will still receive a field sobriety test and the officer still must show probable cause to make an arrest. But if that happens, drivers can no longer refuse a blood test.