My question involves a traffic ticket from the state of: Colorado

Specifically, it involves Colorado Springs Municipal code: 10.17.102-Obedience to Official Device (catchall code for signage).

I entered a two lane traffic circle at the 6 position with the intention to exit at the 9 position. I safely entered the outside lane, stayed in that lane and followed the traffic around. As I passed the 12 position, a vehicle on the inside lane turned into my driver's side rear quarter panel (obviously I was mostly in front of that vehicle). She apologized after the accident and said she thought I was going to turn into the 12 position. I was already past that turn and was continuing in my lane when she hit me.

It seemed pretty straight-forward to me, until the officer wrote me a ticket saying there is a sign saying I either need to exit on the first or the second exit (3 or 12 position in this case) and I was not allowed to follow the circle around to the 9 position. He also said I was the primary cause of the accident even though I never deviated out of my lane and I was 2/3 of the way in front of the other vehicle.

The other driver was given a ticket for improper lane change, but I was named as the cause of the accident.

How can this happen? How would a vehicle on the inside lane be more in the right to turn across the outer lane than I was to keep driving in my lane? And how would they even know when I entered the traffic circle? As long as I was in the correct lane, not speeding, and IN FRONT of the other vehicle, how can I be the cause? The officer told me that if I had entered the traffic circle at the 3 position, I would have been completely cleared of all charges and the other driver would have been at fault and the only one ticketed.

Ok, the question is how do I go about fighting this? Not only the ticket, but how can I get the court to recognize I wasn't the primary cause of the accident. This has obvious implications on who pays my insurance deductible. I'm a good driver with a clean record, so the ticket doesn't bother me as much as the insurance issue. I have never had an at-fault accident so I'm pretty bothered by this.

Please help!!