Drinking and driving is illegal. The costs of drinking and driving (DUI ticket, court costs, classes, and increased insurance costs) are not deductible, unless you wrap your truck around a tree.
The Tax Court recently ruled (Rohrs, TC Summ. Op. 2009-190) a drunk driver can deduct his totaled truck as a casualty loss. The Court determined he was not grossly negligent because he had made arrangements to be driven home from the party, but later thought he was OK to drive elsewhere. His blood alcohol level was just over the limit and his insurer denied his claim due to the DUI arrest. The Court granted the deduction because he tried to act reasonably.
The Court would have denied the claim if he drove straight home from the party. They consider that gross negligence.
I hang my head in shame. The Tax Court has taken a position of encouraging drinking and driving. Lower taxes are always better in my opinion, but supporting an illegal act is crazy. Next, the Court will rule that property seized due to drugs will be rewarded with a large tax break. Maybe the Tax Court can hand out free drinks and weed in the last hour before closing time.