Auto insurance is mandatory because it serves several important purposes, including financial protection for both the insured and other drivers on the road. In the event of an accident, mandatory auto insurance ensures that drivers have a minimum level of coverage to cover damages and injuries sustained by themselves and others. This helps prevent uninsured drivers from causing financial hardship for those involved in accidents, as well as reducing the overall burden on society due to uncompensated medical expenses and property damage. Additionally, mandatory auto insurance promotes responsible driving behavior by discouraging risky actions that could lead to accidents and costly claims. Overall, the requirement for auto insurance is a crucial component of modern road safety and financial security.