I was driving toward downtown Portland on the 84/30 during the tail end of rush hour last night, so traffic was starting to slow down around the tight curves near 33rd Ave. No biggie, a bit annoying, but expected. I was in the left lane, actively passing traffic in the other two. A slow down happens near 21st Ave, and as traffic starts to debunch and clear up a bit, a car in the middle lane merges in front of me... and proceeds to drive slower than the cars in front of it. At this point on the Banfield, the lane I'm in is in planning for where I'm going: Auxiliary lane to exit at Lloyd Blvd (Lloyd Center, Convention Center, bypass bad freeway congestion to get to Rose Quarter or Steel Bridge via surface streets); right lane for Rose Quarter, Steel Bridge, or I-5 north; middle lane for Morrison Bridge, or I-5 south; or left lane to move into the far left lane of I-5 south as quickly as possible to transition to I-405 north.
With that said, 21st Ave is still a mile east of the 84's end, and slower traffic still has time to observe lane discipline (and the 84 -> 5 south ramp is two lanes); I wound up needing to pass the car that merged in front of me on the right and get back into the left lane.
A quirk about the ramps from the 84 to the 5 is that they're still in the 55 zone for the 84, and there are no advisory speeds posted, yet traffic routinely tends to go 45 through there.
Speaking of advisory speeds, Portlanders seem to take them as gospel, most annoyingly on the I-205 south -> US 26 west ramp under Division St.