Following too closely is determined by weather, road, traffic conditions, etc. and commonly appears in police reports of auto accidents as a cause of an accident.  The fact that the other driver left the road but was still struck by your vehicle would not alter the finding of following too closely.A negligence claim is based on exercising due care (that degree of care that a reasonable person (driver in this case) would have exercised under the same or similar circumstances to avoid foreseeable injury)).  This will be used to determine "following too closely" despite the precautions that you took to avoid the accident.CA uses comparative negligence which means that you would NOT be 100% liable for the accident.  The other driver was partially at fault.  For example, if the other driver is determined to be 80% at fault for the accident and you are determined to be 20% at fault, then you would only be liable for 20% of the other driver's damages while the other driver would be liable for 80% of your damages.I am just using these figures for example.  The actual determination of each party's liability for the accident under comparative negligence will most likely be different than these figures.If you disagree with the insurance carrier's findings regarding liability for the accident, you can challenge it in court; however, if the police report says that you are liable for the accident due to following too closely, it will be very difficult for you to prevail as the court relies on the police report's determination of the cause of the accident.