Evaluation of Red Light Cameras Safety

Improvement Program in Alabama

Fatemeh Baratian Ghorghi

PhD Student at:

Auburn University, Department of Civil Engineering

INTRODUCTION

• Background

• Objectives

• Literature Review

• Data Collection

• Data Analysis

• Suggestion based on the results

BACKGROUND

• RLR crash, the most common/most severe type of crash

• More than 165,000 injuries in 2008

• RLC supplement Law enforcement efforts

• National Survey

• Opponents: a tool to gather revenue

• No study evaluates the effectiveness of RLCs in AL

• Safety benefits

OBJECTIVES

Evaluate the effectiveness of RLC systems in Opelika

1. Safety Impact

2. Operational Impact

Quantify the economic performance

LITERATURE REVIEW

1. Evaluation of camera’s safety effects (20)

2. RLCs Site Selection (10)

3. RLR Behaviors (6)

1- Past findings of safety effects

• Reduced violation rate by about 40% during the first year

• Reduced right-angle crashes (injury and fatal) 19% - 32%

• Increased rear-end crashes (PDO) up to 40%

• The costs were offset by benefits

2- Studies of RLCs Site Selection

Effective factors:•AADT, high ratio of RA to RE crashes, shorter inter-green periods and cycle length

•Collision severity, commercial vehicles, net economic cost, feasibility of site installation

•High number of collisions, dispersion of intersections

•Larger number of lanes of the primary-street, fully actuated traffic signals

3- Studies of RLR Behaviors

• Increase in average traffic speed, and heavy vehicles, reduces RLR in low AADT

• Violators under 30 were not speeding

• 94% within 2 s, between 2 PM and 3 PM

• Shorter green-to-cycle time, increase in time to cross, and following another vehicle suggests a lower likelihood

Two studies in Alabama

1. A pilot study of feasibility for using RLC (2003)

2. A general guideline developed to assist site selection and implementation of RLC program in Alabama (2014)

RLC in Alabama

8 communities in Alabama:•Birmingham•Center Point•Foley•Midfield•Montgomery•Opelika•Phoenix City•Tuscaloosa

RLC in Opelika, AL• April 1, 2013

• The overall safety effect is not clear.

DATA COLLECTIONThe exact location of RLCsTraffic volume for each approach per hourIntersection geometric featuresSigning and publicitySpeed limit

? Program start and end date

? Citation

? Signal timing and control type

? Crash and violation frequency (Min 2 weeks for #/h and 3 years before and after for #/year)

Field Data Collection

CARE Software• Right-angle plus rear-end crashes

• Not clearly defined in crash reports

• 2,210 out of 21,020 in Alabama

DATA ANALYSIS

1. Safety impact: EB method, Crash prediction models, Crash modification factors

2. Economic performance: benefit-and-cost analysis, Crash reduction benefit, Cost of the camera

3. Operational impact: Field data collection, Driver’s behavior study

Running Behavior

(a) (b)

(c) (d)

Running Behavior

Suggestions

1. Site Selection: Where to install?

2. How much fine?

Timeline

• Starting from January1st, 2014

• Literature Review (April 1st, 2014)

• Identify Required Information (May 1st, 2014)

• Field Observation (June 15th , 2014)

• Data Collection (September 15th , 2014)

• Data Analysis (March 1st , 2015)

• Interpretation of Results & Recommendation (August 1st , 2015)

• Final Report (December 31st , 2015)

Thank You!