Designing for Speed, Congestion, and Delay in the Work Zone (PowerPoint Presentation)

Slide 1. Designing for Speed, Congestion, and Delay in the Work Zone

Gerald Ullman
Research Engineer
Transportation Operations Group
Texas Transportation Institute

Slide 2. Work Zone Safety Trends

Graph of work zone fatalities of 600 to 1,400 per year for 1996 to 2003: 700 in 1996, 650 in 1997, 790 in 1998, 900 in 1999, 1,050 in 2000, 1,000 in 2001, 1,200 in 2002, and 1,050 in 2003.

Slide 3. Work Zone Safety Trends Pie Chart

no work zone influence=71%, work zone indirectly involved=19%, work zone conditions directly involved=6%, during work zone setup/removal=4%

Slide 4. Work Zone Consequences

Approximately 40,000 injuries/year nationally
Approximately 120 workers killed annually
Approximately $4.5 billion/year national economic cost

photo of roadway warning sign stating "slow down or die"

Slide 5. Some other facts…

43,500 miles of the National Highway System sees at least one day of work zone activity annually
In summer, we lose the equivalent of 41 million vehicles per day of roadway capacity due to work zones

Cartoon of a flagger holding a sign stating "Road work next 15,000 miles."

Slide 6. Work Zone Exposure

Slide 7. The Result…

Beetle Bailey cartoon. The first panel shows General Halftrack riding in a car and saying into a cell phone "Hello, Bureau of Missing Persons?" The second panel shows his car in a traffic jam stretching over hills and into the distance. Channelizing cones and work zone signs stating "Slow" and "Slow, work area" are on both sides of the roadway. His speech balloon shows "I'd like to report a missing road repair crew."

Real Life Adventures cartoon showing a road sign stating "2 left lanes closed for no reason whatsoever next 21 miles."

Slide 8. Speed Management in Work Zones

Enforcement
Speed control technologies

Slide 9. Enforcement considerations

Realistic and "reasonable" speed limits
Adequate coordination between DOT and enforcement agencies
Labor availability

photo of signs next to roadway stating "work zone, traffic fines double" photo of police officer ticketing a driver

Slide 10. Enforcement

Circulating: 2–3 mph lower
Stationary: 3–13 mph lower
Police Traffic Controllers: 2–14 mph lower
Operation Hardhat: ???

photo of police car parked next to roadway photo of workers on a road maintenance machine aiming a radar gun

Slide 11. Work Zone Speed Control Technologies

Enforcement surrogates
Driver information/feedback
Perceptual methods

Slide 12. Enforcement Surrogates

"Dummy" vehicles: –
Unmanned radar: 0–2 mph lower
Remote enforcement: –
Automated enforcement: –

photo of a traffic camera above a roadway computer screen showing photo of a car's rear license plate

Slide 13. Driver Information/Feedback

Changeable Message Signs (CMS): 0–2 mph lower
CMS with radar: 0–6 mph lower
Speed trailers: 2–10 mph lower
CB Wizard: 0–2 mph lower
Variable Speed Limits: 0–5 mph lower

night photo of portable message board showing speed of approaching traffic

photo of portable message board showing speed of approaching traffic as 35 mph

Slide 14. Perceptual Methods

Rumble strips: 1–6 mph lower
Transverse markings: 0 mph
Narrowed lanes: 0–8 mph lower

photo of a roadway narrowed with moveable barriers on each side

photo of rumble strips across a lane

Slide 15. Congestion and Delay Management in Work Zones

Increase work zone capacity and efficiency of flow
Reduce traffic demands at work zone bottleneck points
Communicate accurate estimates of delay and congestion expectations

Slide 16. "Get In, Get Out, Stay Out"

77% motorists prefer long-term repairs, even if delays are more significant
Focus on longer-lasting materials, better construction methods, longer service life horizon
Major constraint: money

Slide 17. Increasing Capacity

Late-merge or dynamic merge control
Moveable barrier systems
Contractor accountability

Slide 18. Late Merge

Slide 19. Moveable barrier

photo of a moveable barrier transfer machine

Slide 20. Contractor Accountability

Arizona SR 68 (FHWA-HOP-04-032)
$400k incentive pool
Travel times exceeding 27 minutes reduced incentive pool

photo of Arizona State Route 68 photo of traffic camera and lights next to highway

Slide 21. Reducing Traffic Demands

Working at night and weekends
Full roadway closures
Portable Intelligent Transportation System (ITS) technology

Slide 22. Extent of Nightwork

Slide 23. Concerns about Nightwork

Efficiency, quality of work
Safety
- Traveling public
- Workers
Worker quality of life

Slide 24. Full Roadway Closures

Roadway completely closed, traffic routed to alternative routes
Increases work efficiency
Eliminates traffic/work crew conflicts
Requires high degree of coordination and contingency planning
Impacts off-site difficult to predict and assess

Slide 25. A Broader Perspective

map of Katy, Texas, showing a section of Katy Freeway circled within a larger circle superimposed on the city

Slide 26. ITS Applications in Work Zones

photo of moveable message board screen shot of web site for Lake Springfield Bridge message boards and traffic conditions

Slide 27. Key principles

Motorists should not be told something they already know
Motorists should never be provided incorrect information (must maintain credibility)
Motorist diversion thresholds: 10–20 minutes delay

Slide 28. Questions

Questions?

Slide 29. Transportation Management Plan

Temporary Traffic Control (TTC) Plan
Transportation Management Considerations
Public Information Considerations

photo of warning sign stating "lane drop ahead" next to unfinished highway bridge construction