Sec. 18. (a) In a criminal action brought under section 16 or 17 of this chapter, it is a defense that the operation of a motor vehicle was necessary to save life or limb in an extreme emergency. The defendant must bear the burden of proof by a preponderance of the evidence to establish this defense.
(b) In an action brought under section 16 or 17 of this chapter, it is a defense that the defendant was operating a motor driven cycle, unless the defendant was operating the motor driven cycle in violation of IC 9-21-11-12. The defendant must bear the burden of proof by a preponderance of the evidence to establish this defense.