Melbourne cup day saw three drink and drug drivers caught in Port Lincoln.
On Tuesday afternoon police were undertaking a driver testing site on the Lincoln Highway when a 49-year-old man from Seaford Rise returned a positive reading of 0.068.
The driver on his provisional licence was issued an expiation notice.
Later that evening police stopped a red Mitsubishi sedan on Matthew Place at Port Lincoln for random driver testing.
The driver, a 47-year-old man from Port Lincoln returned a positive reading for methamphetamine.
About four hours later police stopped a Mitsubishi utility on Mortlock Terrace for a driver test.
The 20-year-old man from Port Lincoln returned a positive reading for methamphetamine.
Both samples have been sent for further testing with results pending further chargers for the drivers.
A 26-year-old Port Lincoln woman was also detected drug driving in Port Lincoln yesterday afternoon.
Just after 3 pm on Wednesday Police Patrols stopped a Jeep on London Street for driver testing.
The 26-year-old driver allegedly returned a positive reading for methamphetamine.
The sample has been sent for further testing and pending the results, she may be charged with drug driving.