That graphic came from the Facebook Post from the former WSDOT North Spokesperson.
They nixed the flyover early in the design process, as it was inadequate for growing demand and the costs associated with it. The biggest problem is that the original design had a fly under for eastbound traffic, which was removed in the final design. That being said, the overall design has been perfect, just the poor drivers coming from the West who can't read signs, lane markings, or traffic movements are the problem. The crashes are also far less severe than those from the light, which were often T-bones, instead of side-swipes.
WSDOT needs to just keep it as is, and if anything, remove an eastbound lane, rather than a southbound lane.
What's their name? Is it a public post?
Unfortunately, though the bolded statement may be true, there is a significant amount of evidence that this is the case at virtually all multi-lane roundabouts country-wide, and the engineers should have known this would be a problem. I'm sure engineers and planners are totally stumped by this. I know I am. But it's true, pretty much everywhere. The only multi-lane roundabouts that seem to work are 2x1 roundabouts, where each crossover has no more than three paths crossing (as opposed to the current eastbound entrance, which has four paths crossing (2 over 2)).
The crashes may be less severe, but I may argue the total economic loss is actually greater. Even the most minor crashes usually involve some level of insurance claim, and can also negatively affect vehicle values. Crashes are expensive, and we shouldn't be constructing intersections that routinely cause them. Especially when the old intersection did not have a history of major crashes.
For the record: T-Bone collisions are absolutely possible at roundabouts, but especially multi-lane roundabouts. All drivers have to do is ignore the lane lines (say, by failing to notice the approaching roundabout) and head straight-on into circulating traffic. It's actually quite easy. If drivers followed the rules, of course this wouldn't be the case. But if drivers followed rules, we wouldn't have crashes now, would we?!?!
WSDOT could reduce the eastbound entry to one lane, but that would decrease SR-20 Spur to SR-20 to one lane in each direction, half the capacity of the original signal (and then some...traffic is moving slower now as well). Factor in the possibility for continued crashes with less capacity, and we're left with...well: