Take I-5 South toward Portland, Ore. Once in Portland, do yourself a scenic favor and ride into downtown via the Fremont Bridge. It’s majestic. Other transportation options include the train, which has wonderful scenic views in the daytime. Plus the architecture and interiors of the Seattle and Portland stations are a sight to see.
For more direct travel, take the BoltBus. As a seasoned veteran of the train and bus, I can vouch that tickets for both methods of transport are cheaper to buy in advance.
Source: http://dailyuw.com/
