The in basket: Ian MacKenzie wrote the
Road Warrior shortly after a fatal accident at one of Kitsap
County’s yellow flashing left turn signals in Silverdale last
While saying he loves the signals and
considered them a great benefit to moving traffic, he adds, “after
all this time, I am still finding that there are a lot of people
out there that are still confused by them and don’t know what
“As a result,” he said, “they often do
one of two things: Sit there and do nothing and the light turns red
and they wait for the next green arrow cycle, or they think the
light is changing to red so they bolt through the turn in front of
oncoming cars. The recent tragedy and death at the intersection of
Kitsap Mall Boulevard and Randall Way could easily have been the
result of the latter.”
He said the city of Federal Way augments
the flashing yellow left turn signals there with a sign with
wording to the effect of Left Turn Yield on Flashing Yellow.
“Has or did Kitsap County consider
placing signs of this nature to help with the confusion that many
still seem to have? Have there been many accidents
attributable to the flashing arrows?” he asks.
Southbound Kitsap Mall Boulevard at
Randall Way is the only intersection I know of with adjoining left
turn lanes both controlled by flashing yellows. Ian thinks having
two cars side by side making the turn on yellow might negatively
affect behavior of or visibility for the drivers.
The out basket: Jeff Shea, Kitsap
County traffic engineer, says, “Flashing yellow arrows (FYA)
are the most popular new technology I’ve seen in the 16 years I
have been working in the traffic field. With just about all
new technological innovation though, it brings with it a learning
curve and complaints from motorists.
“It is rare when motorists applaud new efforts, even when the
new device improves operations and/or safety. In the case of the
FYA, we received many positive observations regarding the
technology, and comments from motorists indicating that they are
“The ability to turn left when no opposing traffic is present
allows them to move through intersections more quickly with less
frustration. The previous signal indication used to allow
permissive left turns was the green ball over the turning lane.
This created confusion for a few motorists as they sometimes
interpreted the signal as a protected left turn, rather than a
permissive one. It is permissive in terms that they had to
yield to oncoming traffic, whereas protected means they are given
the right of way to make the left turn.
“Because of this, we have phased out the green ball for
permissive turns because the FYA provides motorists with a much
better understanding of the permissive nature of the turn.
“Tens of thousands of motorists navigate through FYA
intersections in Kitsap County every day without incident.
(But) FYA signals do not eliminate collisions at
intersections. Misunderstanding signs and signals can play a
part in these collisions, but they are not always the primary
He said the federal Manual on Uniform Traffic Control Devices
recently accepted yellow flashing left signals for traffic control
and the county adheres to the requirements of that manual.
“Prior to authorizing this new technology,” Jeff said,
“extensive research was done by the National Cooperative Highway
Research Program. Over a seven-year period, comprehensive research
was conducted, including engineering analyses, static and
video-based driver comprehension studies, field implementation,
video conflict studies, and crash analyses. The FYA was determined
to be the best overall alternative to the circular green, and it
had a high level of understanding and correct response by
“We review collision records regularly looking for trouble
spots, and we rely on direct reports from the Sheriff’s Office at
locations where deputies see frequent collisions. We pay
special attention to those areas where new signs or traffic devices
are installed, including the FYAs.
“There have been a few collisions attributable to motorists not
yielding on a flashing yellow arrow; exactly how many is difficult
to tell from the reports. Some of these collisions report a lack of
understanding of the signal, others happened when the motorists
misjudged how close the opposing traffic was.
“What records don’t show is how many collisions this technology
reduces. Permissive left turns can reduce motorist’s
frustration and lessen the likelihood for motorists to make a ‘mad
dash’ to get through the intersection before the protected turn
“They understand that they need to wait only for the opposing
traffic to clear and then proceed through the intersection, rather
than having to wait a full cycle for the next protected turn. The
signal may also reduce rear-end collisions by reducing the number
of motorists that abruptly stop in front of another motorist for
the same reason as above.
“The FYA greatly improves the intersection’s capacity. More
vehicles can get through the intersection during the same amount of
time. The FYA … significantly shortens the queue for left
turning vehicles. This allows us to shorten the left green
signal and give more green time to the other movements at the
intersection. This in itself can reduce driver frustration
and possibly reduce overall collisions at the intersection.
“Kitsap Mall Boulevard and Randal Way is a unique intersection
in that we have a two left-turn lanes. There have been a few other
collisions here including a tragic fatality and we are considering
“We are evaluating installing a sign on the mast arm to remind
motorists to yield on the FYA. If any intersection that uses FYA
shows high collision rates we will consider this enhancement and
other solutions including limiting the times of day for permissive
left turns, or eliminating the permissive turn altogether,” Jeff
About the same time Ian wrote me, Patrick and Sherri Burch also
did, suggesting the yellow flashers be replaced by red flashers.
We’ll talk about that in the next Road Warrior column