pilot study - parts i & ii - nyc

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Reduced School Speed Limit Pilot Study - Parts I & II

School Safety Engineering

June 24th, 2008Janette Sadik-KhanCommissioner

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Pilot I• Pilot I : Began in 2005 to test reduced speed limits • 10 streets adjacent to schools in the Bronx• 8 out of 10 streets had “speed reducers”• Both 20 MPH and 15 MPH zones were tested

Signal15P.S. 279

Signal20St. Luke

Stop15P.S. 291

Signal15P.S. 110

Stop15P.S. 102

Signal20P.S. 30

SignalNo20M.S. 399

SignalNo20I.S. 166

Stop20P.S. 90

Signal15P.S. 79

Control at School Crosswalk

Speed Reducer (Hump)

Posted School Speed Limit (MPH)

School

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Pilot I – Preliminary Conclusions

• Reduced speed limits at schools may be effective on minor residential streets that do not already have existing speed reducers.

• Speed reducers are an effective tool (regardless of whether there is a lower speed limit opposed to a lower advisory speed) to ensurelow speeds (~20 mph) on minor residential streets.

• Reduced speed limits, in addition to existing speed reducers, have limited value.

Future Study on streets without speed reducers necessary in order to make more conclusive determination of the impact of reduced speed limits on streets without speed reducers.

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Pilot I - Results

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Pilot II 2007

Data Collected:• Vehicle speed and volume• Vehicle classification and turning movements• Pedestrian volume• One “Before” and two “After” periods (March 2007 – December 2007)• Two mid-week days for each period

Street Criteria:• One-way street with one travel lane adjacent to a school building• Street not designated a truck route or bus route• Length of block more than 200 feet• Located in advance of a designated school crosswalk, controlled by either a

traffic signal or a stop sign• No Speed Reducers

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Reduced Speed Zone: Test TreatmentEach Street received…• Flashing beacons during school hours 7AM – 4 PM

accompanied by reduced speed limit signs -20 MPH• Signs indicating Speed Zone Ahead• Signs indicating End Speed Zone

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Pilot II - Ten Schools

Signal

Stop Sign

Signal

Signal

Signal

Stop Sign

Signal

Signal

Signal

Signal

Type of Traffic Control at intersection with

school crosswalk

77th Street from 37th Road to 37th Avenue

42nd Avenue from 108th Street to 104th Street

Harman Street from Irving Avenue to Knickerbocker Avenue

Suydam Street between Irving Avenue and Wyckoff Street

Woodbine Street from Evergreen Avenue to Bushwick Avenue

Bleecker Avenue from Knickerbocker Avenue to Wilson Avenue

Willoughby Avenue from Cypress Avenue to Saint Nicholas Avenue

Hoffman Street from East 189th Street to East Fordham Road

Arthur Avenue from East 179th Street to East 180th Street

Walton Avenue from Mount Hope Place to East 176th Street

Street with Reduced Speed Limit

10

9

8

7

6

5

4

3

2

1

#

77-02 37th AvenuePS 69Queens

41-15 104th StreetPS 16Queens

220 Irving AvenuePS 86 Brooklyn

100 Irving AvenuePS 123 Brooklyn

88 Woodbine StreetIS/PS 299 Brooklyn

1300 Greene AvenueIS 383Brooklyn

1390 Willoughby AvenueIS 162 Brooklyn

2502 Lorillard PlaceMS 45 Bronx

57 East 179th StreetJHS 118 Bronx

1865 Morris AvenueJHS 117 Bronx

School AddressSchool Boro

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23.7

21.2

24.2

21.1

1819202122232425

MPH

ALL SCHOOOLS

AM BEFORE AM AFTER PM BEFORE PM AFTER

Pilot II Overall Results: Speeds Decreased in AM and PM

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Pilot II Overall Results: Speed Decreased Over Time

23.7

21.8

20.7

24.2

21.8

20.5

18

19

20

21

22

23

24

25

MPH

AM BEFORE AM AFTER 1 AM AFTER 2PM BEFORE PM AFTER 1 PM AFTER 2

10

Pilot II Results: Change by Type of Traffic Control

at Intersection Downstream

23.4

21.1

24.1

21.0

24.8

21.6

24.8

21.6

18

20

22

24

26

Signal St op SignCont rol Device Downst ream

Signal vs. Stop Sign Speeds


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AM Speed Reduction (MPH)

2 2 . 5

2 0 . 5

2 8

2 1. 5

2 3 . 5

2 0 . 3

2 22 1. 5

2 5

2 2 . 5

2 4

2 0 . 5

2 2 2 2 . 3

2 3 . 5

2 2 . 5

2 4 . 5

2 0 . 8

2 2

2 0 . 0

16

18

20

22

24

26

28

30

MP

H

JHS 117 JHS 118 M S 45 IS 162 IS 383 IS/ PS 299 PS 123 PS 86 PS 16 PS 69

SCHOOLS AM BEFORE AM AFTER

12

25.0

20.0

29.5

20.8

24.5

20.0

23.0

20.0

24.0

22.5

24.0

21.0

22.0

23.323.0

22.5

25.5

20.8

21.5

20.3

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

MP

H

JHS 117 JHS 118 MS 45 IS 162 IS 383 IS/ PS299

PS 123 PS 86 PS 16 PS 69

S C H OOL PM BEFORE PM AFTER

PM Speed Reduction (MPH)

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AM Speeds over time (MPH)

22.5

21

20

28

21.521.5

23.5

19.5

2122

22.5

20.5

25

24

21

24

22.5

18.5

2222.5

22

23.5

22.522.5

24.5

21

20.5

22

20.5

19.5

16

18

20

22

24

26

28

30

MP

H

JHS 117 JHS 118 MS 45 IS 162 IS 383 IS/ PS 299 PS 123 PS 86 PS 16 PS 69

SCHOOLS

AM BEFORE AM AFTER 1 AM AFTER 2

14

2 5

2 1

19

2 9 . 5

2 2

19 . 5

2 4 . 5

19

2 1

2 3

2 1. 5

18 . 5

2 4

2 4 . 5

2 0 . 5

2 4

2 2 . 5

19 . 5

2 2

2 3 . 5

2 3 2 32 2 . 5 2 2 . 5

2 5 . 5

2 1. 5

2 0

2 1. 5

19 . 5

2 1

16

18

20

22

24

26

28

30

MP

H

JHS 117 JHS 118 M S 45 IS 162 IS 383 IS/ P S 299 P S 123 PS 86 P S 16 PS 69

SCHOOLS

PM B EF OR E PM AFTER 1 PM AFTER 2

PM Speeds over time (MPH)

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Results: JHS 117, Bronx

22.521

20

25

2119

161820222426

JHS 117 Cha nge in Spe e ds ove r Time


22.520.5

25.0

20.0

1618202224262830

MPH

JHS 117

JHS 117 Before and After Speeds


AM speeds were reduced 8.9% from an average of 22.5 mph to 20.5 mph.

PM speeds were reduced 20% from an average of 25.0 mph to 20 mph.

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Results: JHS 118, Bronx

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21.5 21.5

29.5

2219.5

1618202224262830

JHS 118Change in Speeds over Time


28

21.5

29.5

20.8

1618202224262830

JHS 118Before and After Speeds


AM speeds were reduced 23.2 % from an average of 28 mph to 21.5 mph

PM speeds were reduced 29.7 % from an average of 29.5 mph to 20.8 mph

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Results : MS 45, Bronx

23.5

20.3

24.5

20.0

16

18

20

22

24

26

MPH

MS 45Before and After Speeds


23.5

19.521

24.5

1921

161820222426

MP

H

MS 45Change in Speeds over Time


AM speeds were reduced 13.6% from an average of 23.5 mph to 20.3 mph

PM speeds were reduced 18.4% from an average of 24.5 mph to 20 mph

18

22 22.5

20.5

2321.5

18.5

16

18

20

22

24

MP

H

IS 162Change in Speeds over Time


23.5

20.3

24.5

20.0

161820222426

MP

H

IS 162Before and After Speeds


AM speeds were reduced 2.3% from an average of 22 mph to 21.5mph

PM speeds were reduced 13% from an average of 23 mph to 20 mph

Results : MS 162, Brooklyn

19

2524

21

24 24.5

20.5

161820222426

MP

H

IS 383Change in Speeds over Time


AM speeds were reduced 10% from an average of 25 mph to 22.5 mph

PM speeds were reduced 6.3% from an average of 24 mph to 22.5 mph

25

22.524.0

22.5

161820222426

MPH

IS 383Before and After Speeds


Results : IS 383, Brooklyn

20

24

22.5

18.5

24

22.5

19.5

16

18

20

22

24

MP

H

PS 299Change in Speeds over Time


AM speeds were reduced 14.6% from an average of 24 mph to 20.5 mph

PM speeds were reduced 12.5% from an average of 24 mph to 21 mph

24

20.5

24.0

21.0

16

18

20

22

24

MP

H

PS 299Before and After Speeds


Results : MS 299, Brooklyn

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AM speeds increased by 1.4% from an average of 22 mph to 22.3 mph

PM speeds increased 5.9% from an average of 22 mph to 23.3 mph

22 22.322.0

23.3

1618202224

MP

H



22 22.5 2222

23.5 23

16

18

20

22

24

MP

H



Results : PS 123, Brooklyn

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PM speeds were reduced 2.2% from an average of 23 mph to 22.5 mph

23.5

22.5

23.0

22.5

22

22.5

23

23.5

MP

H



23.5

22.5 22.5 23 22.5 22.5

16

18

20

22

24

MP

H



Results : PS 86, Brooklyn

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PM speeds were reduced 18.4% from an average of 25.5 mph to 20.8 mph

24.5

20.8

25.5

20.8

161820222426

MP

H



24.5

21 20.5

25.5

21.520

161820222426

MP

H



Results : PS 16, Queens

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AM speeds were reduced 9.1% from an average of 22 mph to 20 mph

PM speeds were reduced 5.6% from an average of 21.5 mph to 20.3 mph

22

20.0

21.520.3

16

18

20

22

MPH



22

20.5

19.5

21.5

19.5

21

16

18

20

22

MP

H



Results : PS 69, Queens

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Conclusions from Pilot II

Flashing Beacons accompanied by 20 MPH reduced speed limit signs resulted in a reduction of speeds:AM Speeds decreased overall from 23.7 mph to 21.2 mph (a 10% decline) PM Speeds decreased overall from 24.2 mph to 21.1 mph (a 12% decline)

Speeds decreased over time:7.8% after the 1st “after” AM speed test

12.3% after the 2nd “after” AM speed run 9.5% after the 1st “after” PM speed run 12.3% after the 2nd “after” PM speed run

This shows that reduction of speeds can be maintained over several months.

Traffic Control:• On streets with downstream signalized intersections speeds decreased 9.9% and 12.9% in the AM

and PM respectively • On streets with downstream stop controlled intersections speeds decreased and 12.6% in the AM and

PM.

JHS 118 had the largest decline in speed. Speeds decreased 23.2% in the AM and 29.7% in the PM.

PS 123 in Brooklyn was the only school not to show a decrease in speed. Speeds increased slightly from 22.0 mph to 22.3 mph in the AM and from 22.0 mph in the PM to 23.3 mph.

pilot study - parts i & ii - nyc

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