DULUTH, MN (KDAL) - The Christmas season isn't so merry if you spend it in jail.  Duluth Police are joining other area police departments, the St. Louis County Sheriff's Department and the Minnesota State Patrol in enhancing DWI patrols to get impaired drivers off the roads.  The agencies are increasing the enforcement during the statewide "Drive Sober or Get Pulled Over" effort that starts Thursday and continues through the month of December.  Those planning to attend Holiday parties will need to plan ahead for a sober ride home or be arrested.