J.,

To the best of my knowledge, lane splitting is NOT legal in either Washington or Oregon.

Fortunately, the 308 miles of I-5 in Oregon only has 2-3 cities of enough size to do more than slow you down. Eugene could be slow, if you happen to hit at rush hour. Portland is the largest city in Oregon and I-5 runs right through the middle. An alternative would be to take the I-205 freeway. It cuts off south of Portland, and re-joins north of Vancouver, WA. It is a little longer than staying on I-5, but not much, and it used to be a little faster. My knowledge of the area is getting dated, so things could have changed.

Once you get north of Vancouver, WA, it should be relative smooth running till you start getting close to the Seattle/Tacoma area.

Construction might be your biggest worry.

You have made the trip before, so you are familiar with most of the roads. For an cool sight, take I-205 around Portland, and stop in Oregon City and look at the waterfall. It is right beside the freeway and is a pretty cool site. It looks kinda like a mini Niagara. It's good for a "stretch out the legs" stop for a few minutes.

Be sure to wave at all my relatives in Vancouver, WA when you pass through.

I hope you have a great and safe run. I would take rain gear if possible. The saying in that part of the country used to be... "Summer happens on a Tuesday". They do get some long dry spells, but they don't call WA the Evergreen state for nothing. It doesn't usually rain very hard, but it's not uncommon to have a light drizzle that seems to go on & on.

Putz