Not necessarily. There are many factors that can cause a single-vehicle accident. One of the most common examples is defective roadways. Drivers are not able to control sudden hazards on the road that are often the responsibility of governmental agencies that manage the roadways.
You will want to inform your insurance company of any external factors that caused or contributed to your single-vehicle crash because it may be possible that another party is liable for the accident.
Another common cause of single-vehicle accidents are mechanical malfunctions with the vehicle, which are beyond the drivers’ control to manage. Manufacturers or maintenance companies may be held liable for these kinds of issues.