Safe Speed Limits For Seattle
FREQUENTLY ASKED QUESTIONS
Who supports the 20/25 MPH idea?
Many community, public health, school, business, and advocacy groups are
asking for safer speed limits. We hope you will too after learning more about
how this idea will save lives!
What’s the idea for non arterial streets (neighborhood streets)?
A safe and livable 20 MPH speed limit for every neighborhood street in
Seattle. Currently, the “default” speed on non-arterial streets is 25 MPH -
faster than you probably drive on neighborhood streets. 20 MPH streets will
be safer for us all, particularly people walking and kids playing.
What’s the idea for arterial streets?
Streets that are known to be dangerous should have speed limits examined,
and potentially reduced to 25 MPH, as part of a comprehensive safety
strategy. Additionally Communities should be able to request the city work with them to reduce
arterial speed limits especially in areas such as business districts and through community hubs.
Traﬃc should be smooth and safe and people should be able to get where they need to go reliably
Will changing the speed limit save lives?
Yes. Changing the speed limit will make our streets
safer for everyone!
Each year in Seattle about 20
people are killed in traﬃc collisions and another
150 are seriously injured. 42% of of these
collisions involved speeding. Driving even a little
slower gives us all more time to see each other and
makes it easier to stop. Well-established research
even a small speed decrease makes a
big diﬀerence. Vehicle stopping distance improves
by 45 feet (23%) when travelling at 25 MPH versus
30 MPH. If a collision does happen, nine out of ten
people hit by a driver going 20 MPH will survive,
while at 30 MPH survival rates decrease to only ﬁve
out of ten.
Will 20 MPH for neighborhood streets mean I’ll take longer to drive anywhere?
. On non-arterial (neighborhood) streets, it is already diﬃcult to drive faster than 20 MPH due to
roundabouts and narrow street widths. When people do speed it is especially dangerous for elders
and children living and playing in their neighborhoods.
Would a 25 MPH for arterial street make my commute longer?
First of all, this proposal does not change all arterial streets to 25 MPH (see FAQ above). Not likely
Most people drive during rush hour, when it’s already diﬃcult to drive fast. Travel time is primarily
determined by factors like traﬃc signals, congestion, and turning vehicles. Moreover, a top reason for
congestion in Seattle is traﬃc collisions. Reducing speeds will reduce collisions and reduce the
frequency of collisionrelated congestion. People driving outside of peak travel times may see a slight
increase in their travel time. If you’re going 30 MPH without any interruptions, a lowered speed limit of
25 MPH will add about 1 minute to your trip (the average car trip in Seattle is about 3.5 miles). We
think the occasional extra minute is worth it to save someone’s life.
When would the speed limits change, and which streets would be aﬀected?
A default 20 MPH speed limit for non-arterial neighborhood streets could take eﬀect as soon as the
signs could be changed, except where they are currently signed to 15 MPH (as they are in some
The 25 MPH limit for arterial streets would be implemented on a case by case basis over time with
community and SDOT evaluation (this is the model used by every other city in King County). Only
then would speed limit signs be changed and a 25 MPH limit enforced.
Are there other cities with 20/25 MPH speed limits?
Yes. 20 MPH neighborhood streets are widely seen as a best practice around the world to keep
neighborhoods safe and comfortable places to live in and raise families.
Every other city in King
County has a default speed limit of 25 MPH or lower. Many other large cities around the world,
including New York, Los Angeles, Washington D.C., London, Paris, Berlin, and Tokyo, already have a
speed limit set to 25 MPH or lower to improve drivers’ ability to avoid crashes.
Isn’t 20/25 MPH just a way to raise additional revenue for the City?
Not at all. Seattle should reduce its speed limit in order to make the city safer for people walking,
biking, and driving. A lower speed limit helps meet the City’s goal of bringing traﬃc fatalities to zero.
Data shows that driving at or below 25 MPH improves drivers’ ability to avoid crashes.
Sometimes streets are just dangerous. Why focus on speed?
Dangerous driver choices, such as speeding, failure to yield, and improper turns, are the primary
cause or a contributing factor in 70% of pedestrian fatalities. Legislative eﬀorts, such as lowering the
speed limit, combined with engineering street safety improvements, education and enforcement work
together to create safer streets for us all.
What is Vision Zero?
Seattle’s goal for traﬃc fatalities and serious injuries is the same you would want
for you and your family: zero (this goal is called Vision Zero). While zero fatalities
may seem ambitious, it’s the same standard we expect of our airline system. It’s
also about the idea that you should be able to make mistakes without being
punished by death. 20/25 MPH is a great way to improve drivers’ ability to avoid
For more information or to get involved contact
Created by Neighbors for Vision Zero