Call the local DMV and Police Department and ask for a list of complaints and incidents about that curve. If necessary, you could file a FOIA request or let your insurance company do that. Give all the info to your insurance company and have them go after the state/city to cover the cost including your deductable. It would be helpful if you had a police report to document what happened and their investigation but it appears you didn't. You can probably still get satisfaction if there are sufficient complaints/incidents at that location. At the very least it might force the state/city to fix the problem so someone doesn't get killed.
GONE: '08 335i Coupe, Space Gray, Coral Red, Gray Poplar, 6-MT, ZSP, ZPP, ZCW, 19" Style 230 Wheels, Nav, CA, PDS, Sat, HD, IPod. ED 10 May '08.
NEW ARRIVAL: '11 M3 Convertible, Mineral White, Fox Red, Extended Leather, Carbon Leather, 6-MT, 19" Style 220M Wheels, EDC, EPS, ZP2, ZCV, ZCW. ED 29 Apr '11