Hearings and Trials: Same Judge Allowed for Trial by Written Declaration As Trial De Novo

My question involves a traffic ticket from the state of California, in Riverside County.

Is it legal for the same judge to preside over a traffic citation's Trial by Written Declaration, and then the same citation's pursuant Trial de Novo?

If it were the same judge, wouldn't that mean the judge would NOT be neutral and detached in the Trial de Novo?

Hearings and Trials: Same Judge Allowed for Trial by Written Declaration As Trial De Novo