what are the odds the insurance company will settle out of c

I hit a pot hole in a construction zone that was unmarked and un protected. It was a county project. I have evidence to prove they knew about the pot hole and the construction company caused the hole to re-open with their equipment. However, they are both denying my claim. The construction company had sub-contractors milling the road. Do I sue the county and the main construction company or do I sue everyone that I know stepped foot on the grounds (i.e. water companies, sub contractors, etc.)? Or, should the main construction company and the county be good enough?

How likely is it that the construction companies insurance will settle out of court?