Veh. Code, § 40519

(a) Any person who has received a written notice to appear for an infraction may, prior to the time at which the person is required to appear, make a deposit and declare the intention to plead not guilty to the clerk of the court named in the notice to appear. The deposit shall be in the amount of bail established pursuant to Section 1269b of the Penal Code, together with any assessment required by Section 42006 of this code or Section 1464 of the Penal Code, for the offense charged, and shall be used for the purpose of guaranteeing the appearance of the defendant at the time and place scheduled by the clerk for arraignment and for trial, and to apply toward the payment of any fine or assessment prescribed by the court in the event of conviction. The case shall thereupon be set for arraignment and trial on the same date, unless the defendant requests separate arraignment. A deposit of bail under this section does not constitute entry of a plea or a court appearance. A plea of not guilty under this section must be made in court at the arraignment.

(b) Any person who has received a written notice to appear may, prior to the time at which the person is required to appear, plead not guilty in writing in lieu of appearing in person. The written plea shall be directed to the court named in the notice to appear and, if mailed, shall be sent by certified or registered mail postmarked not later than five days prior to the day upon which appearance is required. The written plea and request to the court or city agency shall be accompanied by a deposit consisting of the amount of bail established pursuant to Section 1269b of the Penal Code, together with any assessment required by Section 42006 of this code or Section 1464 of the Penal Code, for that offense, which amount shall be used for the purpose of guaranteeing the appearance of the defendant at the time and place set by the court for trial and to apply toward the payment of any fine or assessment prescribed by the court in the event of conviction. Upon receipt of the plea and deposit, the case shall be set for arraignment and trial on the same date, unless the defendant requests separate arraignment. Thereafter, the case shall be conducted in the same manner as if the defendant had appeared in person, had made his or her plea in open court, and had deposited that sum as bail. The court or the clerk of the court shall notify the accused of the time and place of trial by first-class mail postmarked at least 10 days prior to the time set for the trial. Any person using this procedure shall be deemed to have waived the right to be tried within the statutory period.

(c) Any person using the procedure set forth in subdivision (a) or (b) shall be deemed to have given a written promise to appear at the time designated by the court for trial, and failure to appear at the trial shall constitute a misdemeanor.