You may get a reduction of the fine if you go to court
and plead "guilty with an explanation". You can tell the Judge that you had to exit and there were no nearby breaks in the double yellow line separating the commuter lane from the other lanes.
Or you could just plead not guilty.
21460. (a) When double parallel solid lines are in place, no person
driving a vehicle shall drive to the left
thereof, except as
permitted in this section.
(b) When the double parallel lines, one of which is broken, are in
place, no person driving a vehicle shall drive to the left thereof
except as follows:
(1) That the driver on that side of the roadway in which the
broXXXXX XXXXXne is in place may cross over the double line or drive to
the left thereof when overtaking or passing other vehicles.
(2) As provided in Section 21460.5.
(c) Either of the markings as specified in subdivision (a) or (b)
does not prohibit a driver from crossing the marking when (1) turning
to the left at any intersection or into or out of a driveway or
private road, or (2) making a U-turn under the rules governing that
turn, and either of the markings shall be disregarded when authorized
signs have been erected designating offcenter traffic lanes as
permitted under Section 21657.
(d) Raised pavement markers may be used to simulate painted lines
described in this section when the markers are placed in accordance
with standards established by the Department of Transportation.
The statute says "no person shall drive to the left" of a double yellow line, but you apparently crosse to the right of the double line to get to the exit. So technically you are not guilty.
You can tell the judge you are either not guilty or might be guilty but give your explanation and point out that the statute does not prevent you from crossing over to the right side of a double yellow line in this situation. How else can you get to the exit?
I hope this information is helpful.