Innovative Work Zone Traffic Control and Technology

1
Innovative Work Zone Traffic Control and
Technology

• Mike Fontaine
• Virginia Transportation Research Council
• Making Work Zones Work Better Workshop

2
Work Zone Problems

• Capacity reduction
• Increased queuing
• Delays
• Safety
• Crash rate increases 7 to 119 percent
• Rear end crashes most common
• Speeding is often a factor

3
Objective

• Describe techniques that could improve safety
  and/or operations in work zones
• DOT controlled
• Portable
• Cost effective

4
Devices Covered

• Worker garments
• Rumble strips
• Radar drones
• Speed displays
• Late merge

5
Worker Garments

• Potential camouflage problem
• Evaluated 5 garments
• Field testing inconclusive

6
Worker Garment Evaluation

• Luminance (brightness)
• Contrast ratio
• Concrete
• Asphalt
• Vegetation
• Equipment
• Orange TCDs

7
Garment Assessment

• Solid fabric garments performed best
• Highest luminance
• Best contrast against variety of backgrounds
• Concerns about comfort in Texas
• Proposed TxDOT vest was the best of the mesh
  vests
• Does not meet new ANSI standard

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TxDOT Vest Before After
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Temporary Rumble Strips

• Reduce speeds
• Increase driver awareness

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Temporary Rumble Strips

• ¼ inch thick neoprene strips
• 4 inches wide
• Adhesive backed
• 2 sets of 6 strips installed on work zone
  approaches
• 18-inch spacings

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Rumble Strips Results

• Evaluated at 2 sites
• 1-2 mph reduction in car speeds
• 3-4 mph reduction in truck speeds
• Not reusable
• Lengthy installation time (40 minutes)
• Noise concerns

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Radar Drone

• Emits K band radar signal
• Intended to simulate enforcement
• 1 mile range
• Approx. 400

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Radar Drone Results

• Evaluated at 3 sites
• 2 mph speed reduction
• Easy to use
• Effectiveness may decline over time

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Speed Display

• Provides motorist feedback on speeds
• Radar drone effect
• 10,000

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Speed Display Features

• 24-inch LED display
• Strobe alert
• Worker alert siren
• Battery powered

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Speed Display Results

• Evaluated at 4 sites
• 5 mph reduction in average speeds
• 10-30 reduction in number of vehicles exceeding
  speed limit
• Easy to set-up and remove

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Changeable Message Signs with Radar

• Message only displayed to speeders
• 5 mph reduction maintained for 4 months

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Lane Closure Issues

• Problems stemming from lane closures
• Reduced capacity
• Increased travel times
• Increased driver frustration
• Aggressive driving and queue jumping

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The Late Merge Concept

• Late merge
• Utilize all approach lanes to merge point
• Shorter queues
• Possible improved throughput
• More equitable distribution of delay

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Late Merge Applications

• Pennsylvania
• First deployments
• Wide deployment on freeways
• Texas
• Tests in Dallas/Fort Worth
• Freeways
• Virginia
• Tests on primary roads

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Late Merge
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Pennsylvania Late Merge
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Pennsylvania Late Merge
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Virginia Late Merge
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Virginia Late Merge
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Late Merge

• Benefits
• Up to 15 increase in throughput
• 75 fewer forced merges
• 30 reduction in lane straddles
• Reduced queue length
• Potential Limits
• Approach taper at high speeds under low volumes
• Driver understanding
• Use on roads with gt 2 lanes

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Summary

• A number of tools are available to improve work
  zone safety and operations
• Improved worker visibility
• Reduced speeds
• Increased flow

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Questions?

• Mike Fontaine
• Michael.Fontaine_at_VirginiaDOT.org
• [phone]