San Luis Obispo Police say drivers may experience delays tomorrow night at an undisclosed location. The department will be conducting a DUI checkpoint somewhere within the city limits. Officials say the checkpoint will be in operation between 8 p.m. Friday to 2 a.m. Saturday. impaired driving can be caused by alcohol, prescription medications, over-the-counter drugs, and medicinal and recreational marijuana. First time DUI offenders face an average of $13,500 in fines and penalties and a suspended license.