Text from 'Sequential Warning Light System for Work Zone Lane Closures' PowerPoint Presentation
Slide 01
Title: Sequential Warning Light System for Work Zone Lane Closures
by Melisa Finley, Gerald Ullman, & Conrad Dudek for the
Making Work Zones Work Better Workshop
From the Texas Transportation Institute
Transportation Operations Group
Slide 02
Title: Background
- Individual flashing warning lights.
- The 2000 MUTCD states "Flashing 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
Slide 03
Title: Purpose
To reduce the chance of vehicles running into a work zone lane closure
at night by increasing conspicuity and by increasing location and direction
information at the closure taper
categorized
Slide 04
Title: Warning Light System
Photo of a road at night-time of traffic cones with lit with LED lights and lined along the road shoulder.
Slide 05
Title: Warning Light System
- Wireless
- Radio controlled
- Up to 16 lights
- Up to 80 ft apart
- Components
- LED warning light
- Transmitter-receiver case
Slide 06
Title: Research Plan
- Closed-course
- Motorist comprehension
- Earlier lane-changing
- Field
- Operational effects
- Safety benefits
Slide 07
Title: Closed-Course Studies
- Nighttime
- 59 subjects
- Motorist performance
- Motorist preference
Slide 08
Title: System Designs
- No-light background
- Steady-burn light background
Slide 09
Title: Treatments
- No lights
- Steady-burn lights
- Steady-burn light background system w/ 60 fpm
- No-light background system w/ 17 fpm
- No-light background system w/ 60 fpm
Slide 10
Title: Comparison of Treatments
Diagram: This graphic compares the percentage of subjects that found treatments helpful vs. those that found them confusing, displayed for each of four treatments.
- For the first treatment Steady-Burn, 68 percent found it helpful, while 4 percent found it confusing.
- For the second treatment Steady-Burn with 60 fpm, 79 percent found it helpful, while 10 percent found it confusing.
- For the third treatment No-Light with 17 fpm, 56 percent found it helpful, while 29 percent found it confusing.
- For the fourth treatment is No-Light with 60 fpm, 45 percent found it helpful, while 34 percent found it confusing.
Slide 11
Title: Motorist Preferences
Diagram: This graphic is a pie chart comparing four motorist preferences. The Steady-Burn Light Background System was preferred by 42%. The No Light Background Systems were preferred by 20%. The Steady-Burn Lights were preferred by 16%. No Warning Lights were preferred by 22%.
Slide 12
Title: Field Studies
- Nighttime
- Treatments
- No lights
- Steady-burn light background system
- Measures of performance
- Speeds
- Lane choice & erratic maneuvers
Slide 13
Title: 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
Slide 14
Title: Results (part 1 of 2)
- 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
Slide 15
Title: Results (part 2 of 2)
Diagram: This graphic compares the percentage of Vehicles in Closed Lane 1000 feet from Taper with and without a system. The vehicles are divided into Passenger and Commercial categories.
In the case of Passenger Vehicles the result is 30 percent without the system and 23 percent with the system.
In the case of Commercial Vehicles the result is 19 percent without the system and 7 percent with the system.
Slide 16
Title: 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
Slide 17
Title: 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
Slide 18
Title: 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
Slide 19
Title: Questions?
Photo: of traffic cones in the later afternoon
Slide 20
Title: Contact Information
Melisa Finley, TTI
979-845-7596
Jim Kennedy, Empco-Lite
800-548-5483 or 847-931-2455
