I was stopped for failing to obey a traffic control device. This occurred at the intersection of University and 3rd Avenue in downtown Seattle at 510pm on October 26, 2005.
Apparently, they have changed the rules on 3rd Avenue in the last six weeks (before I was stopped) so that right turns are only allowed from 6-9a and 3-7p. I didn't see these signs since during the entire time I was on 3rd Avenue before I was stopped (about two blocks), I was driving to the left of and behind large buses, which blocked my view of the signs at the corner of the intersection as well as the top signs. (Note that the change regarding the lanes was due to the downtown bus terminal being redone, which has resulted in a LOT of bus traffic on 3rd Avenue especially during rush hour.
In fact, when I was stopped, I didn't know why. To point out the sign that I had ignored, the officer told me look behind and there was a bus blocking whatever it is he wanted me to see. He then told me to wait for the bus to pass by so I could see the signs!
I have taken photographs documenting this. These were taken (around 2p) from the sidewalk--the pictures from the driver's seat would be more egregious (i.e., would block more).
The solution then is that these signs should be also added to the buses themselves, and also to the left hand of the driver (i.e., the other side of the street). Currently, there are signs giving warnings to drivers driving in the opposite direction, but these are empty white boards on the other side.
These pictures illustrate the corner "no entry" sign blocked
by a bus on the right. Note that the reflection of the sign you see on
the bus is actually from the other side of the street. Look at the
building details and make sure everything lines up (see also picture
below for reference). Also note the amount of blockage above and
beyond the sign and up through the light.
These pictures illustrates how the corner and the right only sign
These four pictures illustrate how the top sign can be blocked
if you're behind a bus: