Signs that switched places

[corco]

So I just encountered something very...odd as I was going through my photo collection. It looks like between 2008 and 2018, a couple similar but not identical reassurance shields were swapped on SR 17 in Moses Lake, Washington. Check this out:

SR 17 northbound milepost 55.68, July 2008:


Note the somewhat odd proportions of the shield compared to normal and the lack of the drop case, which has been standard WSDOT spec for at least the last decade.

Now here's what's there in May 2018:


Which, okay, they maybe just replaced that sign with another more modern but not up to current spec sign.

But then check this out up at milepost 56.72:

Here's what was there in July 2008:


Which, okay, that's a pretty generic pre-mid 2000s WSDOT unisign reassurance shield, but maybe not the exact same sign as in the previous photo.

But check out what's there now:


What? That's clearly the sign that was at 55.68 back in 2008. It looks like something happened that caused the shields to get swapped.

Has anybody ever seen this happen before?