Santa Clara county launched its "Avoid the 13" campaign with an emotional plea from the father of a 4-year old boy killed by a drunk driver last month.
Jesus Cortez of Gilroy urged people to think twice before they drink and drive.
"My family is not the same, because we miss our family very much, because he was a very happy child," he said.
In addition to the crackdown in Santa Clara County, 25 Contra Costa County law enforcement agencies will be out in force looking for drunk drivers, as well starting this weekend.
Both campaigns run through Labor Day weekend.