This is referred to as an “uncontrolled intersection” under Washington law.
There is a statute in the Rules of the Road, RCW 46.61.180, stated in relevant part below, that indicates that you simply yield the right of way to any vehicle on your right-hand side.
Interestingly, however, despite the clarity of the law, the pattern jury instruction for these types of cases, WPI 70.02, also stated below, includes a sentence that the driver on the left also has a duty to exercise ordinary care to avoid a collision.
What is, therefore, the right thing to do?
My best advice is something my dad told me when I was a kid and we were on a bike ride. There was a car backing out of a driveway and I thought they could see me clearly, but as we approached the driveway the car did not stop. I only stopped after getting so close that my dad had to yell out to me to stop because he was concerned that I was putting myself in a bad situation. I explained to him that I thought the car would stop and that it was his obligation to stop. My dad said that I was right, but what good would that do me if the car kept going and ran me over?
So, most uncontrolled intersections are in neighborhoods where there is a low-speed limit anyway. Even if you know the law and know you have the right of way, it is best to slow down more and make sure that the car on your left is going to yield the right of way before you barrel on through. Better safe than sorry.
Vehicle approaching intersection—Vulnerable users of a public way—Fine. (Effective until January 1, 2025.)
(1) When two vehicles approach or enter an intersection from different highways at approximately the same time, the driver of the vehicle on the left shall yield the right-of-way to the vehicle on the right.
WPI 70.02 Right of Way—Uncontrolled Intersection
A statute provides that when two vehicles approach or enter an intersection from different streets or roadways at approximately the same time, the driver of the vehicle on the left shall yield the right of way to the vehicle on the right. This right of way, however, is not absolute but relative, and the duty to exercise ordinary care to avoid collisions at intersections rests upon both drivers. The primary duty, however, rests upon the driver on the left, which duty must be performed with reasonable regard to the maintenance of a fair margin of safety at all times.