Yes, in California (as in most states) not wearing your seat belt properly is the same offense as not wearing a seat belt at all and thus you are cited for that traffic violation.
The California Highway Patrol (CHP) notes that a person be cited for detaching the shoulder strap or putting it under his/her arm. It is illegal for a motorist to disable a shoulder strap if it is part of the vehicle's manufactured safety system.
CA Vehicle Code Section 27315 is the Mandatory Seat Belt Law and states in part that a person shall not operate a motor vehicle on a highway unless that person and all passengers 16 years of age or over are properly restrained by a safety belt. As you see it specifically states that you must be properly restrained by the seat belt, not just buckled up.
So there is not a difference in having your seat belt on but not using it properly and not having it on at all and thus as you said you can now pay the ticket, take your lumps and move on.
California's seat belt law requires that drivers and all passengers must be protected by safety belts. There are some narrow exceptions, including persons with health problems who carry a current letter from a physician or chiropractor. If you have some medical reason to wear your seat belt improperly than you should get a doctor's letter to carry with you in case you are stopped by CA police again for a seat belt violation.
The CHP site states that if the safety belt is too tight or rubs your neck, ask your local car dealer to adjust it. You can also place a soft cloth or piece of sheepskin on the belt where it touches your neck to make it more comfortable and use your seat belt properly.
The CA Vehicle Code notes that a seat belt violation is an infraction punishable by a fine of not more than twenty dollars ($20) for a first offense, and a fine of not more than fifty dollars ($50) for each subsequent offense. In lieu of the fine and any penalty assessment or court costs, the court, pursuant to Section 42005, may order that a person convicted of a first offense attend a school for traffic violators or another court-approved program in which the proper use of safety belts is demonstrated.
The fine listed for a ticket for the 27315 offense on the CA Uniform bail schedule is $76.00. This is for a first offense so as you can tell the $20 penalty grows a bit when you add on court costs, county fees, etc. The ticket itself or the court listed on your ticket can tell you the exact amount your fine will be for your seat belt ticket.
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