There are good reasons the Washington Association of Police and Sheriffs and the Washington State Law Enforcement Firearms Instructor Association oppose I-594. It won’t prevent criminals getting firearms, but its mandated bureaucratic paperwork would waste resources that could otherwise be spent fighting crime.
Supporters of I-594 like to claim background checks have prevented 40,000 felons, domestic abusers and others from purchasing firearms in Washington state. If this were true, there should be an additional 40,000 people incarcerated, since attempted purchase of a firearm by a prohibited person is a crime. Since they are not incarcerated, we may assume 40,000 people were unjustly prevented the exercise of a constitutional right.
If I-90 is closed, you may use Sprague Avenue. If Sprague is too congested, you may try Trent Avenue. There are many alternates available to you.
Similarly, if background checks obstruct a criminal’s acquisition of a firearm, he may go to a family member or a compadre, resort to theft, or a black market transaction. The threat of a background check will only cause the criminal to take an alternate route to his objective, just as a road closure will cause you to change your route.
A nuisance, not a prevention.