Sequential Warning Light System for Work Zone Lane Closures

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Sequential Warning Light System for Work Zone
Lane Closures

• by
• Melisa Finley, Gerald Ullman, Conrad Dudek
• Making Work Zones Work Better Workshop

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Background

• Individual flashing warning lights
• 2000 MUTCD statesFlashing warning lights shall
  not be used for delineation, as a series of
  flashers fails to identify the desired vehicle
  path.
• Sequential flashing warning lights
• Series of synchronized flashers
• Used in Europe

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Purpose

• To reduce the chance of vehicles running into a
  work zone lane closureat night
• By increasing conspicuity
• By increasing location and direction information
  at the closure taper

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Warning Light System
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Warning Light System

• Wireless
• Radio controlled
• Up to 16 lights
• Up to 80 ft apart
• Components
• LED warning light
• Transmitter-receiver case

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Research Plan

• Closed-course
• Motorist comprehension
• Earlier lane-changing
• Field
• Operational effects
• Safety benefits

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Closed-Course Studies

• Nighttime
• 59 subjects
• Motorist performance
• Motorist preference

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System Designs

• No-light background

• Steady-burn light background

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Treatments

• No lights
• Steady-burn lights
• Steady-burn light background systemw/ 60 fpm
• No-light background system w/ 17 fpm
• No-light background system w/ 60 fpm

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Comparison of Treatments
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Motorist Preferences
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Field Studies

• Nighttime
• Treatments
• No lights
• Steady-burn light background system
• Measures of performance
• Speeds
• Lane choice erratic maneuvers

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Sites

• Site 1
• Rural
• Low volume
• 65 mph
• 2 lanes ? 1 lane
• Closure 6 months old

• Site 2
• Urban
• High volume
• 65 mph/55 mph
• 3 lanes ? 1 lane
• New closure

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Results

• No effect on speed
• No effect on erratic maneuvers
• No effect on lane choice at Site 1
• Did effect lane choice at Site 2
• of vehicles in closed lane lower with system

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Results
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Implementation

• Not justifiable in all cases
• Greatest potential safety benefit
• Short duration or intermediate-term projects
• Low number of familiar drivers
• Concerns about nighttime path guidance visual
  clutter

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Example of Use

• US 59 west of Houston
• 3 month project
• Converting existing mainlane shoulders to
  auxiliary lanes between access ramps
• Majority of work at night
• Lane closure locations change nightly

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Keep in Mind

• Still an experimental device
• Approval for experimentation must be granted by
  the FHWA
• Section 1A.10 of the MUTCD outlines the necessary
  steps to apply for experimentation

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Questions?
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Contact Information

• Melisa Finley, TTI979-845-7596
• Jim Kennedy, Empco-Lite800-548-5483 or
  847-931-2455