The easy answer is “It's required by law.” But, beyond the illegality of driving uninsured—other risks loom for folks who drive uninsured.
As I just alluded to, Washington and Oregon each have minimum auto insurance requirements (see Washington's Financial Responsibility statutes here and Oregon's here). Most drivers choose to buy auto insurance coverage in order to meet this obligation and it's a good idea for reasons beyond just complying with your state laws.
For one, it ensures that—if you injure someone while driving—they will have some monies available to compensate them for the damages they suffer (not to mention that you won't have your own personal assets taken from you in order to satisfy any judgment they may get against you if you are found to have been at fault). Further, if you secure more than the mandatory minimum liability coverage and get critical coverages like personal injury protection (PIP) (explained here) and uninsured/underinsured motorists coverage (UIM) (explained here)—you will likely ensure that you will have some monies available to compensate you for the damages you suffer.
Moreover, it's usually a good idea to consider purchasing higher liability coverage limits. The insurer you choose will most likely only be required to pay up to the limits of your liability coverage—even where the damages suffered by another in the collision are much greater. But, if you are “at-fault” in a collision, you will ultimately be expected to pay any damages (for example, the other driver's medical bills, lost wages, and property damage) that your liability insurance limits do not cover.
It is always possible, too, to get pulled over by a police officer—even for having a taillight out. If you do get pulled over, you will need to prove you have met the financial responsibility requirements and have the appropriate documentation to do so available in your vehicle at all times. For example, in Washington, driving without having met the financial responsibility requirements and causing a collision can result in substantial fines or even a driver's license suspension.
Beyond all of the reasons drivers should be insured outlined above, a critical reason for driving insured in Oregon is to ensure the viability of your potential personal injury claim should you have the misfortune of being involved in a motor vehicle collision. Under Oregon Revised Statute 31.715, persons injured in a collision who were driving without auto insurance at the time of the collision are not allowed to submit claims of non-economic damages to the jury. This could potentially have a staggering negative impact on the value of an injured person's personal injury claim.
Non-economic damages are defined by statute in Oregon (ORS 31.710) as: “subjective, nonmonetary losses, including but not limited to pain, mental suffering, emotional distress, humiliation, injury to reputation, loss of care, comfort, companionship and society, loss of consortium, inconvenience and interference with normal and usual activities apart from gainful employment.” These are contrasted with economic damages such as medical bills, lost wages, and other damages to which a tangible value can be ascribed.
Non-economic damages are often valued well in excess of the economic damages a person might have suffered in a collision. Thus, by driving uninsured in Oregon, you are undercutting any potential opportunity you might have to recover for the damages you might suffer if you are ever hurt in an automobile collision.
If you have questions about auto insurance in Washington or Oregon or if you aren't sure how to proceed in the wake of being involved in a collision, please feel free to give us a call.