It's legal in Oregon and Montana as long as you stay in the shoulder. You can walk there too. I can't remember the law in Washington.

In western states with a lot of rural places only serviced by interstate they sometimes never passed blanket prohibition against non-motorized traffic on the interstate property.

> I can't remember the law in Washington.

I'd bet I-5 in Seattle is bicycles prohibited, but there's no blanket prohibition of bicycles on freeways. Like you said, there's a lot of parts of Washington where the freeway is the only reasonable road, so you can't prohibit bicycles or pedestrians.

Bikes that have motors and don't fit the e-bike tiers are motorcycles ... and could potentially be legal to operate on a bicycle prohibited freeway, but they'd need to be registered and it looks like these don't have plates, and the operator would need a DOT motorcycle helmet which was not present, and I'd bet these are also missing out on the lights and stuff you need too.

You can bike at some places on I-90 in Washington state where better options aren't available. I don't think it applies to E-bikes though, or at least the ones that can go faster than 15 MPH.

It is/was legal on rural interstates in Washington. I've cycled down I90 in roughly the North Bend area (in the late 90's).

Yes, sometimes the interstate is the only reasonable route through a pass in the western US.

You know, the law banning kids from driving vehicles that can go over a certain speed is also already on the books. The new law is just a clarification that no, you can't be an 11 year old going 40 MPH with an unlicensed E-bike.

The big problem is just Seattle being incredibly underpoliced and really no laws under homicide are really enforced or punished.