Pedestrian Safety Countermeasures Deployment and Evaluation: Las Vegas Case Study

Shashi NambisanDirector, InTrans & Professor of Civil Engineering

Iowa 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 locationsCrash index and crash rank

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

its proximity)• Different jurisdictionsCity of Las VegasCity 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

!!

I 15

US 95 UP

RR

SAHARA AV

CAREY AV

FLAMINGO RD

TROPICANA AV

WASHINGTON AV

JONES B LVD

OWENS AVNELLI S B LV D

CHARLESTON BLVD

EASTERN AV

DEC AT U R B LV D

LAS

VEGA

S BL

VD

LAMB BLVD

RANCHO DR

VEGAS DR

STEWART AV

LAKE MEAD BLVD

BOULDER HWY

VALLEY VIEW BLVD

INDU

STRI

AL R

D

PARADISE RD

BRUCE ST

FREMONT ST4TH

ST

MARYLAND P KW

Y

MA RTI N L K ING

BLV D

SPRING MOUNTAIN RD

SWENSO

N ST

VEGAS VALLEY DR

CABANA DR

SMOKE RANCH RD

PECO

S R D

DESERT INN RD

SANDS AV

BONANZA RD

CIVIC CENTER DR

MO

UNTAIN VISTA ST

TWAIN AV

COM

MERC

E ST

4TH STTWAIN AV

I 15

LAKE MEAD BLVD

BONANZA RD

TWAIN AV

US 95

PECOS R D

DESERT INN RD

LAMB BLVD

DESERT INN RD

PECOS RD

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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 Treatment12

In-Roadway Knockdown Signs 13

Portable Speed Trailer 14

Turning Vehicles Yield to Pedestrians 15

Danish Offset and Median Refuge16

Pedestrian Activated Flashers 17

Automatic Pedestrian Detection and Smart Lighting Lighting

18

Pedestrian Buttons that Confirm “Call” “Call”

19

Pedestrian Channelization 20

ITS No-Turn on Red Blank out Signs21

Pedestrian Countdown Timers with Animated Eyes22

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 Information 24

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

Ave

rage

Spe

ed (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 Reject 8.1

(13.0) <0.001 Reject

Westbound mph

(kmph)

6.5(10.5) <0.001 Reject 3.7

(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 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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