Final answer:
Add-on coverage in auto insurance allows for personal injury payments without the need to establish fault, providing benefits irrespective of who caused the accident.
Step-by-step explanation:
The type of auto insurance coverage that permits a driver to buy optional coverage, such as personal injury insurance, which allows them to receive payment without determining fault is known as add-on coverage. Unlike traditional liability coverage that pays out to the other party when you are at fault, add-on coverage provides benefits to you regardless of who is at fault in an accident. It differs from comprehensive or collision coverage, which cover non-collision-related events and accidents respectively, and also from threshold coverage that can limit the circumstances under which you can sue for damages.