Dongho Chang, City Traffic Engineer

2016 Louisiana Transportation Confernece

March 2, 2016

Traffic Safety in Seattle Every Day Counts-3 Innovation: Road Diets

Vision: connected people,

places, and products

Mission: deliver a high-quality

transportation system for Seattle

SDOT’s Mission, Vision, and Core Values

Committed to 5 core values to create a city that is:

• Safe

• Interconnected

• Affordable

• Vibrant

• Innovative

Presentation overview

3

• Background on Seattle

• Vision Zero

• Safety Programs

• Questions/discussion

Seattle Context

• 27% of Seattle land area is in public

rights-of-way

• 97.5% of Seattle’s population lives

within ¼ mile of a transit stop

• Ranks 6th of the 50 largest cities for

walkability

• Ranks in the top 5 in bicycle commute

rates for large US cities

• Typical arterial roadway width is 60-66’

Population

5

2015 Population* 2035 Forecast**

Seattle

662,400

782,000

Puget Sound Region

3,898,000

4,980,000

Greater Vancouver

2,474,000

3,226,000

Greater Portland

2,348,000

3,000,000

Greater San Francisco

7,562,000

9,000,000

* Source: US Census, BC Stats

** Source: City of Seattle, WA OFM, BC Stats, Metro, ABAG

2014 Jobs 2035 Forecast

Seattle

515,000

630,000

Employment

• Focus growth to more efficiently serve it Urban centers

Manufacturing & industrial centers

Urban villages

• 80% of city growth in centers/villages since 1994

• Future Comprehensive Plan growth targets 2015-2035 • 70,000 additional housing

units

• 115,000 additional jobs

Seattle’s growth strategy

Why is Downtown Important

Seattle is growing. A lot.

9

5th and Columbia – 43 story tower 9th and Stewart Hedreen Hotel - 43 story tower

Amazon Rufus 2.0 - 37 story tower

177 cars 3 buses

1 light rail train on their bikes

200 people can fit in…

4th Avenue in Seattle

Street Right of Way • Public Space

• Used for Transportation Utility

• Serve our Community’s Diverse Needs

12 BeforeGreg Gilbert Seattle Times

AfterSVR Design

Accommodate Modes Efficiently

13

Vehicle Collisions: World Health Issue

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• 1.24 million deaths per year worldwide from crashes

• 35,200 deaths in US, 3.8 million injuries from crashes

• 440 deaths in WA, 23 deaths in Seattle

2013 Washington Crash Summary

15

• 5,211,033 Licensed Drivers, 6,156,835 Registered Vehicles

• 440,780 Speeding Citations

• 39,478 cell/texting citations, 31,724 DUI

• A crash occurs every 5 minutes

• A person died in a crash every 20 hours

• A speeding driver is in a crash every 30 minutes

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• 14 percent increase

nationally- first increase

since 2007

• 4 percent increase in

Washington State

2014 vs 2015 (Jan – Jun)

Fatal collisions trending up

Vision Zero

Seattle’s plan to eliminate traffic deaths and serious injuries

• Street designs that prioritize safety

• Public education and engagement

• Targeted enforcement patrols

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www.seattle.gov/visionzero

City with Zero Traffic Fatality

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0

5

10

15

20

25

30

35

40

45

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

Traffic Fatalities on Seattle Streets

Total

Pedestrian

Cyclist

Motorcycle

Linear

(Total)

53.9

50.0

55.0

60.0

65.0

70.0

75.0

80.0

85.0

90.0

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05

20

06

20

07

20

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10

20

11

20

12

20

13

20

14

Co

llisi

on

s p

er M

illio

n A

AD

T Tr

ips

Citywide Collision Rate

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Street design, policy and regulation

Urban Center Safety • Reduce collisions in neighborhood business

districts through signal, signage, and street design changes

Citywide speed limit reduction • Reduce speed limit to 30 mph or lower on

arterial streets – Low cost engineering

• Roll out 20 mph Neighborhood Slow Zones – Signage and Pavement Markings

– Improve visibility at intersections for pedestrians

Safety Corridor projects • Reduce crashes on principal arterial streets

including Lake City Way, SW Roxbury St, 35th Ave SW, and Rainier Ave S

20

2015 citywide actions:

Why speed matters

Speed is especially critical for vulnerable travelers

like people walking and biking.

21

Neighborhood Traffic Calming

A lot has been done already

Seattle

• 1,500 Traffic Circles (1,127 inventoried in asset management)

• Reduce injury collision by 97%, all collisions by 90%

• 1,343 Volunteers just for our circles! (1 to 4 volunteers per circle)

•Curb/Planter strip gardening – raised structures requires no-fee permit (sand boxes!)

Traffic calming

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Speed cushions Speed humps

Speed humps

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Small investment with high safety yield Graham Hill Highland Park Olympic Hills

Change in speeding

over 25 mph

-79% -73% -88%

Change in speeding

over 35 mph

-80% -81% -91%

Why Road Diets? Fewer Collisions

US Federal Highway Administration Proven Safety Measure to reduce all collisions by 29%

Standard Rechannelization

Seattle’s Guidelines for Rechannelization Daily volume under

10,000 Yes

Daily volume

10,000 – 16,000

< 700 vehicles per

hour per direction Yes

> 700 vehicles per

hour per direction Synchro model

LOS & Critical

Approaches E or

better

Yes

Applies to 4-lane or 5-lane to 3-lane conversion

Seattle’s Guidelines for Rechannelization

Daily volume more than

25,000 No

Daily volume

16,000 – 25,000 Synchro model

< 30% Increase in

travel time

Corridor LOS D or

better

LOS E or better at

critical approaches

Yes

Every street is different, these are just guidelines

Economic Benefits

Nickerson St: ADT=18,500

Before

After

Nickerson Case Study

Nickerson Case Study

Nickerson Case Study

NE 75th Street

Before

After

• ADT 16,900—21,300

• 2 lanes with peak hour

restrictions to 2 lanes with

two-way left turn lane and

bike lanes

• Residential neighborhood

• Middle school

• High speeds

• Parking removal (140 spaces)

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Top end speeders (10+ mph over the posted speed limit)

reduced 75 percent eastbound and 79 percent westbound

Post-Project Community Feedback

• 2011 Paving Project

• 1.5 Miles in Length

• 3-4 lanes to 2 lanes

• Bus and Bike Improvements

• Community Concerns

Dexter Avenue North

On the Ground: Transit Islands

Before

After

Before

After

• 19% increase in traffic volume

• 11,800 AWDT Before

• 14,100 AWDT After

• 19% decrease in collision rate

• ~40% increase in bus ridership

• Bus travel time approximately same (+0.4 seconds)

Dexter Avenue North

Before After

Dexter Avenue North

0

50

100

150

200

250

300

350

400

Sale

s In

dex

Fiscal Quarter

Impacts to Retail Businesses along Dexter Ave

North

DEXTER

WESTLAKE

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SR

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unnel

(co

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Merc

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)

Am

azo

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ove

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uth

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• Sales index is trending at a positive 5% annual growth rate

• Bicycle ridership increased by 39%

Dexter Avenue North

Dexter Avenue

Dexter Ave

44

Dexter Ave

45

46

7th Avenue

Results Speak for Themselves Street ADT Before ADT

Change

Injury Collisions 85th % Aggressive

Speeding (40+)

Stone Way N 13,900 -6% -33% -5% -75%

Fauntleroy Way SW 17,599 +0.3% -72% -1% -13%

S Columbian Way 12,300 +15% -19% -6% -46%

Nickerson Street 18,500 -1% -20% -21% -93%

NE 125th Street 13,600 +11% -8% -8% -69%

N 130th Street 13,298 +0.5% -75% -15% -87%

Ellis Avenue S 9,855 -39% -24% -4% -30%

Measure Twice: Before & After Data needs Before Study After Study (>1 year)

ADT √ √

Bike and Ped Counts √ √

Injury collisions √ √

10+ over the speed limit √ √

85th percentile speed √ √

Transit operations √ √

Turning vehicle counts √ √

Parking use √ √

Side street diversion √ √

Vehicle classification √ √

Resident satisfaction √ √

Business satisfaction √ √

Rainier Avenue South

Road Safety Corridor

Project area

Roadway characteristics

• Principal arterial

• 4 to 5 lane street

• 50-54 feet wide

• Served by multiple transit routes

• Emergency response route

Rainier Avenue S, between

Letitia Avenue S and

Seward Park Avenue S

Data

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• 1243 crashes (2011-2014)

• 1 crash per day

• Top corridor for serious collisions

• Average time to clear incidents = 47 minutes

• Robust transit use

• Major truck street

• Mixed land uses

Speed studies

52

Posted speed limit on Rainier is 30 miles per hour (mph)

Location 85th percentile speed

Average number of

high-end speeders

(10+ mph over posted

speed limit)

S Hudson Street 35 mph 611/weekday

42nd Avenue S 38 mph 1812/weekday

S Holly Street 37 mph 1083/weekday

S Cloverdale Street 36 mph 1083/weekday

Collision data

Last 3 years

• 1243 total collisions

• 630 injuries

• 2 fatalities

Last 10 years

• Nearly 3600 total collisions

• 1700+ injuries

• 11 fatalities

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Average of 1 crash/day on Rainier

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Collision data

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0

50

100

150

200

250

300

Aurora Lake City Way Rainier (project area)

Crashes per mile

ADT = 37,000 to 74,400 ADT = 34,600 to 40,400 ADT = 19,700 to 28,000

• Modeled the “peak”

period – the hour of

the day where

recorded traffic

volumes were the

highest

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Traffic modeling

Peak period

• Rainier “Pilot” Rechannelization – Option 2 – hybrid design

– S Alaska Street to S Kenny Street (0.9 miles)

– One lane in each direction with center turn lane

– 25 mph speed limit

– Longer pedestrian crossing time at all signals

– Leading Pedestrian Interval at Rainier and Ferdinand

– New parking spaces and more space to park on Rainier

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2015 implementation plan

TYPICAL CROSS SECTION (PLANNED)

TYPICAL CROSS SECTION (EXISTING) 7’

Rainier Avenue S between Letitia and Seward Park Ave S

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Travel times (PM peak)

Pilot

project limits

Direction Existing Anticipated Change

Northbound 10 mins, 43 secs 11 mins, 6 secs +33 seconds

Southbound 12 mins, 36 secs 15 mins, 1 sec +2 mins, 25 secs

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Transit travel times (PM Peak)

Pilot

project limits

Direction Existing Anticipated Change

Northbound 22 mins, 9 secs 22 mins, 28 secs +19 secs

Southbound 16 mins, 27 secs 17 mins, 27 secs +1 min

Rainier Avenue S between Letitia and Seward Park Ave S

Outreach and Engagement

59

Historically underrepresented groups served

by the Outreach and Engagement Program

Afaan-Oromo Speakers

African Americans

American Indians and Alaska Natives

Amharic Speakers

Cambodian (Khmer Speakers)

Chinese (Mandarin and Cantonese Speakers)

Filipino (Tagalog and English Speakers)

Hispanic and Latino Communities

Hmong

Laos Community

Mien

People Living with Disabilities

Renters

Seniors

Small businesses

Somalis

Tigrinya Speakers

Vietnamese

Youth

Communication

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Project Flyer

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Public Outreach and Engagement Liaisons

Community tables with Translators

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Photo: Seattle Neighborhood Greenways

Community Feedback

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Pilot project

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• Before and after at Columbia City

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Rainier Avenue Implemented

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Rainier Avenue Implemented

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Rainier Avenue Implemented

Pilot project

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• Preliminary results

– Travel times

Pre-project Vissim simulation

Average Transit

Travel Time (Rainier

between Genesee

and Henderson)

Change

Northbound 16 mins 57 secs 18 mins 24 secs ~14 mins 30 secs -2 mins 27 secs

Southbound 15 mins 44 secs 17 mins 27 secs ~15 mins 30 secs -14 secs

Preliminary Average Transit Travel Times (PM Peak)

Preliminary Average GP Travel Times (PM Peak)

Pre-project Vissim simulation

Average GP Travel

Time (Rainier

between Genesee

and Henderson)

Change

Northbound 8 mins 50 secs 9 mins 14 secs ~9 mins 4 secs +14 secs

Southbound 9 mins 54 secs 11 mins 49 secs ~11 mins 25 secs +1 min 31 secs

Pilot project

70

• Preliminary results

– Mostly positive feedback

– Speeds

• 85th percentile down 6 mph

– Collisions

• Down approximately 30 percent

2015 - 2016

• Continue Vissim analysis of

design alternatives

• Community design meetings

• Engineering changes from

south to north

• Coordination with Greenway

implementation and Accessible

Mt. Baker project

• Pedestrian signal design

changes at Rainier and Oregon

2015

2016

Phase 2 coordination

72

• Public comments

– Strong desire for protected bike lanes on Rainier

– Extend channelization changes to the north and

south of pilot project

– Add more crosswalks

– Increase enforcement

Phase 2 coordination

73

• Accessible Mt. Baker

– Early implementation

August/September 2016

– Double re-channelization

• Rainier and MLK

– Significant change to

Rainier Valley traffic

patterns

Lessons learned

• Complete corridors can be a preferred context sensitive

approach that may be able to meet multiple community

objectives

• Rightsizing works—over 40 completed examples in Seattle

• Speed reduction—especially for top-end speeders

• Pedestrian and bicycle safety and access encourages more

usage

• Low to no reductions in travel times along the corridors

• Difficult to get initial community support—once installed,

community support is typically very high

Paint and Posts

Our challenge

• Be creative and innovative

• Make safety the number one priority

• Emphasize moving people and goods (not

vehicles)

• Right-size streets to meet your community’s

needs

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Questions?

http://www.seattle.gov/transportation