California Code, Vehicle Code - VEH § 40902

(b) If the defendant elects to have a trial by written declaration, the defendant shall, at the time of submitting that declaration, submit bail in the amount established in the uniform traffic penalty schedule pursuant to Section 40310. If the defendant is found not guilty or if the charges are otherwise dismissed, the amount of the bail shall be promptly refunded to the defendant.

(c) Notwithstanding Division 10 (commencing with Section 1200) of the Evidence Code, the rules governing trials by written declaration may provide for testimony and other relevant evidence to be introduced in the form of a notice to appear issued pursuant to Section 40500, a business record or receipt, a sworn declaration of the arresting officer, or a written statement or letter signed by the defendant.

(d) If the defendant is dissatisfied with a decision of the court in a proceeding pursuant to this section, the defendant shall be granted a trial de novo.