Originally Posted by jackal

Of course, you could always take MAX to Union Station and take Amtrak:

1) Free 24-hour parking at Hillsboro Airport/Fair Complex MAX Park & Ride (or other P&Rs near Hillsboro)
2) MAX fare is 60% of the cost of gas to get to PDX (assuming 25 mpg and not including other incidental costs like wear-and-tear on vehicle)
3) 65-minute travel time on MAX, vs. 45 minutes driving to PDX with no traffic, BUT--
4) Can arrive at Union Station 10 minutes from departure and still be OK
5) Arrival into downtown Seattle (walking distance or a short (<10 minutes) bus/light-rail ride from most offices in downtown)
6) Amtrak tickets starting at $29 each way
7) No TSA!

Just sayin'...