Pedestrian Safety Countermeasures Deployment and Evaluation: Las Vegas Case

StudyShashi Nambisan

Director, InTrans & Professor of Civil EngineeringIowa State University (shashi@iastate.edu)

Srinivas Pulugurtha, The University of North Carolina at CharlotteMukund Dangeti, University of Nevada, Las VegasVinod Vasudevan, University of Nevada, Las Vegas

FHWA’sPedestrian Safety Web Conference

Washington, DCMay 28, 2009

Goals

• Improve pedestrian safety, minimize risk

• Identify, develop, deploy, and evaluate countermeasures

• Case Study: Las Vegas metro area, Nevada

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Introduction

• Significant growth for 20+ years

• Wide, fast street grid network High posted & operational vehicle speeds

• Widely used transit system

• High risk conditions for pedestrians

• Demographics Population ~ 1.8 million Diversity: age, race

• 85 percent of the crashes involved locals

3

Pedestrian Crashes (2003 – 2006)4

Methodology

• Identify candidate locations GIS based analysis Site characteristics Problem characteristics

• Develop, deploy, & evaluate countermeasures

• Measures of effectiveness

5

Study Design

• Before and after Studies

• Comparative studies (with control group)

• Data collection ( ~18,000 pedestrians)

• Statistical analysesParametricNon-parametric

6

Study Locations

• Top priority / high risk locations Crash index and crash rank

• Site selection: 18 locations Includes 4 control locations Excluded the resort Corridor (The “Strip” and

its proximity)

• Different jurisdictions City of Las Vegas City of North Las Vegas Clark County Nevada Dept of Transportation (State)

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Study Locations

Control PointsHigh Pedestrian Risk Locations

R!

Major Streets0 0.7 1.4 2.10.35Miles /

! !R

R !9 10

13 14 15 16

1817

12 11

! R7 8

!!R

123

R !6 5 4

!!

SAHARA AV

CAREY AV

FLAMINGO RD

TROPICANA AV

WASHINGTON AV

JON

ES

BLV

D

OWENS AVN

ELLIS

BLV

D

CHARLESTON BLVD

DE

CA

TU

R B

LV

D

VEGAS DR

STEWART AV

LAKE MEAD BLVD

PA

RA

DIS

E R

D

BR

UC

E S

T

MA

RY

LA

ND

PK

WY

MA

RTIN

L K

ING

BLV

D

VEGAS VALLEY DR

SMOKE RANCH RD

PE

CO

S R

D

DESERT INN RD

BONANZA RD

TWAIN AV4TH

ST

TWAIN AV

US 95

PE

CO

S R

D

DESERT INN RD

PE

CO

S R

D

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Selection of Countermeasures

• Site characteristics Geometric conditions Operating conditions Light conditions Demographics Land-use

• Costs

9

Countermeasures

• Engineering based countermeasures

• ITS based countermeasures

• Others

10

Advanced Warning Signs / Yield Markings11

High Visibility Crosswalk Treatment

12

In-Roadway Knockdown Signs13

Portable Speed Trailer14

Turning Vehicles Yield to Pedestrians

15

Danish Offset and Median Refuge16

Pedestrian Activated Flashers17

Automatic Pedestrian Detection and Smart Lighting

18

Pedestrian Buttons that Confirm “Call”

19

Pedestrian Channelization20

ITS No-Turn on Red Blank out Signs

21

Pedestrian Countdown Timers with Animated Eyes

22

Measures of Effectiveness / Statistical Tests• Pedestrian

Using the crosswalk Captured / diverted Looking for cars before crossing Trapped in the middle of the street Pedestrian-vehicle Conflicts Pedestrian waiting for signal to cross Delay

• Driver Yielding behavior, distance Blocking crosswalk Speed

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Speed Trailer Site Information24

Speed Trailer and Vehicle Speeds

35.0

40.0

31.5 31.9

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Direction of Traffic

Av

era

ge

Sp

eed

(m

ph

)

Before After

54.6 kph

50.7 kph

64.3 kph

51.3 kph

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Speed Trailer: Vehicle Speeds Analysis

MOE

Baseline vs. Stage 1 Baseline vs. Stage 2

DeltaMeanSpeed

P-value H0

DeltaMeanSpeed

P-value H0

H0: Vbefore= Vafter vs. Ha: Vafter< Vbefore

Eastbound mph

(kmph)

5.5(8.9)

<0.001 Reject8.1

(13.0)<0.001 Reject

Westbound mph

(kmph)

6.5(10.5)

<0.001 Reject3.7

(6.0)<0.001 Reject

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Speed Trailer: Analysis of Pedestrians

(Safety) Measures of Effectiveness

Baseline Stage 1 Stage 2

Sample = 165 Sample = 47 Sample = 156

Percent Percent Percent

% pedestrians who look for vehicles before beginning to cross

80 100 100

% pedestrians who look for vehicles before crossing 2nd half of street

85 100 100

% pedestrians trapped in the roadway

41 34 37

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Highly Effective Countermeasures

Description CostAdvanced Yield Markings for Motorists Low

In-roadway Knockdown Signs Low

Pedestrian Countdown Signals with Animated Eyes

Medium

Danish Offset High

Median Refuge High

Portable Speed Trailer High

Pedestrian Activated Flashing Yellow High

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Moderately Effective Countermeasures

Description CostPedestrian Call buttons that Confirm Call (Visible/Audible confirmation)

Low

Turning Vehicles Yield to Pedestrians Low

ITS No-Turn on Red Signs Medium

ITS Automatic Pedestrian Detection Devices

High

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Countermeasures with Low Effectiveness

Description CostWarning Signs for Motorists Low

High Visibility Crosswalk Treatment Medium

Pedestrian Channelization High

Smart Lighting High

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Summary

• Significant overall benefits Pedestrian Driver

• Permitting & deployment considerations

• Administrative / jurisdictional hurdles

• Vendor / procurement difficulties

• Education needs: pedestrians, motorists

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Acknowledgments

• US Dept of Transp., Federal Highway Admin

• Nevada Dept of Transportation

• Nevada Office of Traffic Safety

• Regional Transp Commission of So. Nevada

• Clark County, Nevada

• City of Las Vegas

• UNLV TRC: students, staff

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