In 2012: definitely! They're there 90% of weekday afternoons, 2 p.m.-3 p.m. at least, and I even saw them there on a Saturday night, though that's a rarity. On the weekdays, they take one of these tacks: (1) in-between the two signs; (2) in front of (east) of both signs; or (3) on the ramp itself. It's difficult to say what provokes them, though, as I've seen folks doing at least 70 mph that didn't move them. Perhaps those folks just lucked out, I don't know. I've also seen folks pulled over just shy of - or on - the offramp to I-405 south. To accomplish this from a ramp location, a trooper would need some fantastic driving skills and luck with other motorists getting out of their way during these congested periods, thus I suspect that they work with an accomplice who sets up on the regular 164th on-ramp. In short, you can count on them being there during afternoon rush hours, and after they nab somebody in this direction, they'll either go down to the Lynnwood Transit Center onramp to set up for the northbound lanes, or they'll use the turnaround on the left side opposite the I-405 onramp to go back to the Ash Way overpass (they probably alternate with the accomplice).