In summary: http://www.dmv.ca.gov/pubs/vctop/d11/vc22450.htm
You stand a far better chance at trial if you hire an attorney to handle this matter. If you proceed to trial and represent yourself, it will be your word against the cop. The cop will lie without blinking and the judge will be much more likely to believe a cop when he is not opposed by an attorney. Best of luck in fighting this.
The Vehicle code 22450 outlines the violation. Look it up and you'll have the technical definition for the violation. As for fighting such a ticket, you should consult with a ticket lawyer.
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