We concur in the conclusion of the main opinion herein, directing the issuance of a writ of mandate, but we do so upon the sole ground that the accident out of which the judgment referred to therein arose, having occurred several months prior to the taking effect of section 73 (g) of the California Vehicle *Page 288 Act (Stats. 1929, p. 561), such judgment, though entered subsequent to the taking effect of said amendment, cannot be given effect in seeking to impose the penalty provided in said amendment, for the reason that since the judgment was predicated on an act of negligence committed before the act went into effect, and since the act adds a new penalty for that negligence, said act can have no application to acts of negligence committed before its passage. (Krause v. Rarity, 210 Cal. 644 [293 P. 62]; Callet v. Alioto, 210 Cal. 65 [290 P. 438].) The foregoing conclusion stands upon the threshold of this proceeding and prevents this court from entering upon any consideration of the constitutionality of a statute which has concededly no application to the proceeding before us. It is well settled law that the courts will not give their consideration to questions as to the constitutionality of a statute unless such consideration is necessary to the determination of a real and vital controversy between the litigants in the particular case. Whatever, therefore, has been said in the main opinion with relation to the constitutionality of said amendment to the California Vehicle Act is purely obiter dictum and commits the court to the decision of a question which is not before it in the instant case. Upon the constitutionality of said act we therefore decline to express an opinion.
Shenk, J., concurred in the judgment.