Work Zone Mobility and Safety Program
Photo collage: temporary lane closure, road marking installation, cone with mounted warning light, and drum separated work zones.
Office of Operations 21st Century Operations Using 21st Century Technologies

Text from 'Innovative Work Zone Traffic Control and Technology' PowerPoint Presentation

Workshops > ITS and Mitigation

Slide 1

Innovative Work Zone Traffic Control and Technology

Mike Fontaine

Virginia Transportation Research Council

Making Work Zones Work Better Workshop

Slide 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 contributing factor

Slide 3

Objective

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

Slide 4

Devices Covered

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

Slide 5

Worker Garments

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

Photo of various worker garment styles

Slide 6

Worker Garment Evaluation

  • Luminance ("brightness")
  • Contrast ratio
    • Concrete
    • Asphalt
    • Vegetation
    • Construction equipment
    • Orange TCDs

Slide 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

Slide 8

TxDOT Vest Before & After

Photos: Man in orange vest and white hard hat.

Man in FYG vest and white hard hat.

Slide 9

Temporary Rumble Strips

  • Reduce speeds
  • Increase driver awareness

Slide 10

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

Slide 11

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

Slide 12

Radar Drone

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

Slide 13

Radar Drone Results

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

Slide 14

Speed Display

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

Slide 15

Speed Display Features

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

Slide 16

Speed Display Results

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

Slide 17

Changeable Message Signs with Radar

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

Photo of changeable message sign with radar that reads 'YOU ARE SPEEDING SLOW DOWN'

Slide 18

Lane Closure Issues

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

Slide 19

The Late Merge Concept

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

Slide 20

Late Merge Applications

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

Slide 21

Late Merge

Lane Merge Sequence Graphic: This graphic indicates the sequence of signage when approaching a late merge. Each sign is posted on both sides of the highway. At 7920 feet from the late merge, the sign reads 'USE BOTH LANES TO MERGE POINT'. At 5280 feet, the sign reads 'ROAD WORK 1 MILES'. At 2640 feet, the sign reads 'LEFT LANE CLOSED 1/2 MILE, 50 MPH'. At 1500 feet, the sign reads 'LEFT LANE CLOSED 1500 FT, 45 MPH'. At 1000 feet, the sign reads 'LEFT LANE CLOSED 1000 FT, 40 MPH'. At 550 feet, the sign is a merge symbol that reads '40 MPH'. At 350 feet from the late merge, the sign reads 'MERGE HERE TAKE YOUR TURN'. At the lane merge, a flashing arrow board displays the direction of the merge and cones guide the motorists to the one lane merge.

Slide 22

Pennsylvania Late Merge

Photo of a motorist passing a 'USE BOTH LANES TO MERGE POINT' sign on a Pennsylvania highway

Slide 23

Pennsylvania Late Merge

Photo of a motorist passing a 'MERGE HERE TAKE YOUR TURN' sign on a Pennsylvania highway

Slide 24

Virginia Late Merge

Photo of 'STAY IN LANE TO MERGE POINT 1 MILE' signs lining both sides of a Virginia highway

Slide 25

Virginia Late Merge

Photo of motorists passing 'MERGE HERE TAKE TURNS' signs lining both sides of a Virginia highway

Slide 26

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 > 2 lanes

Slide 27

Summary

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

Slide 28

Questions?

Mike Fontaine

Michael.Fontaine@VirginiaDOT.org

(434) 293-1909

Office of Operations