THE IMPACT OF HIGHWAY SAFETYFLARES ON DRIVER BEHAVIOR

THE IMPACT OF HIGHWAY SAFETYFLARES ON DRIVER BEHAVIOR

Philip M. Garvey

Miguel de la RivaMartin T. Pietrucha

(2003-2005 presented at TRB 2006)

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Introduction

Every year (as of 2005):

507 people are killed.

30,000 people are injured.

350,000 PDMV crashes occur.

Crashes Involving Collisions with Parked/disabled Motor Vehicles

PDMV crashes are the most frequent type of collision with non-fixed objects.

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IntroductionSafety Measures Aimed at Reducing Crashes involving Collisions

with Parked/Disabled Vehicles on Highway Shoulders

Source: www.orionsignals.com

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IntroductionPurpose of Flare Deployment

Warn approaching traffic of unusual road hazard.Mark the location of the traffic incident scene.Prompt a safe response from passing traffic.

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IntroductionAdditional research and more uniform guidance is needed

for safe and effective flare deployment

Number of flares to deployDistance between flaresFlare deployment patternLocation of the leading flareAdded safety benefit of using flares in combination with police car’s light bars

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MethodSite Selection: Blair County, Pennsylvania

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MethodData Collection Equipment

a) Roadway sensors (pneumatic tubes)

b) Automatic traffic recorderc) Export utility software

(TraxproPSU)d) Excel® programmed

worksheets

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Method

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MethodData Collection Equipment: Final Configuration

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MethodBase Flare Configurations Tested

Three flaresFive and Ten paces apart

Six flaresFive and Ten paces apart

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MethodBase Flare Configurations Tested

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MethodRoadway Scenarios Tested

Road Scenario Treatment Description

(a) Police Car + FlaresA 3 flares @ 5 pacesB 3 flares @ 10 pacesC 6 flares @ 5 pacesD 6 flares @ 10 paces

(c) Police Car Only E No flares deployed

(b) Disabled + Flares

F 3 flares @ 5 pacesG 3 flares @ 10 pacesH 6 flares @ 5 pacesI 6 flares @ 10 paces

(d) Baseline None Normal conditions

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MethodMeasures of Effectiveness / Dependent Variables

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MethodData Collection Schedule and Order of Testing

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MethodStatistical Analysis Techniques

ANOVA, Bonferroni, and two-sample t-tests were used for analyses of continuous variables.Contingency tables, Chi-square tests, and the Marascuilo procedure were used for analyses of categorical variables.Conventional 0.05 level of significance was used for hypotheses testing.Minitab® and Excel® used for the computations.

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ResultsSample Size

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ResultsHistogram (with normal curve) of Spot Speeds

(Baseline Condition)

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ResultsLane Distribution

(Baseline Condition)

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ResultsLateral Placement (Baseline Condition)

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Results

…. What happened when treatments were in place?

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ResultsSpot Speed (Experimental Conditions)

Baseline

Passing traffic’s speed was dramatically reduced

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ResultsLane Distribution (Experimental Conditions)

Baseline

a safer zone was created around the emergency event, since high volumes of traffic at high speeds are now as far as possible from the emergency event.

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ResultsLateral Placement (Experimental Conditions)

Baseline

Lateral separation

significantly increased.

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ResultsAnalysis by Traffic Scenario - Speed

Police+Flares Police Only Disabled+Flares Baseline

Baseline≈A few road flares, stored in your trunk and used under emergency situations, would provide a safety benefit comparable to having a patrol car present at the scene.

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ResultsFlare Number - Speed

Three Flares vs. Six Flares

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ResultsFlare Placement - SpeedFive Paces vs. Ten Paces

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ResultsFlare Performance as a Function of Elapsed Combustion Time

First 20 minutes Last 10 minutes

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Conclusions & Recommendations

Road flares significantly enhance the safety around a traffic emergency event and their use is highly recommended for both personal vehicle operators and road safety professionals as a supplement to their flashing light bars.

(Before the 2009 “Steer Clear” law.)