CVC 21658 — Lane Straddling / Unsafe Lane Change

What a California Vehicle Code §21658 citation actually accuses you of, and the angles drivers use to contest one by mail.

What the court has to find

On a roadway divided into lanes, failing to drive as nearly as practical entirely within a single lane, or moving from the lane before it can be done with reasonable safety (subsection (a)).

Defense angles that fit this section

"As nearly as practical" allows momentary, minor deviations — road conditions, obstacles, or wind; whether any other traffic was affected.

The real cost of pleading guilty: penalty assessments multiply the base fine several times over, and a point can raise your insurance for three years. Run the numbers with the fine calculator.

Contest your CVC 21658 ticket by mail

A Trial by Written Declaration lets you fight it without a court date — and losing still leaves you the right to a brand-new in-person trial.

Start with your ticket

This page explains the statute in general terms; it isn't legal advice about your specific case. See the Trial by Written Declaration FAQ for how the mail-in process works.