Work Zone Mobility and Safety Program

Construction Traveler Information System for I–35 Widening in Central Texas

slide 1: Construction Traveler Information System for I–35 Widening in Central Texas

Jerry Ullman
TTI

May 21, 2013
Bettendorf, Iowa

slide notes:

None




slide 2: Overview: I–35 expansion project

  • 200 directional miles – Central Texas
  • 14 segments / 19 projects
  • Costs: ~$2.1B
  • Traffic Volumes
    • 55,000 – 111,000 vehicles/day
    • 66% through trips
    • Trucks: 25% – 30% (75% at night)
    • Over 5 years, ~ 185 million trips
  • TxDOT mitigation of impacts
    • Limited lane closures
    • Blackout dates
    • Completion incentives
  • Complete 2017
Image shows a map of the I-35 Corridor through Falls, McLennon, and Hill County, Texas

slide notes:

Overall, the improvements enhance safety by:

  • bringing the interstate to current design standards,
  • upgrading exits and entrance ramps,
  • converting to one-way frontage roads along the entire length for both access and diversion,
  • adding crossing points as well as U-turns at selected crossings,
  • adding safety rest areas, and
  • reducing congestion through the expansion of capacity.
 

Mitigate construction impacts, including:

  • Access to businesses must be maintained,
  • 6 day work week,
  • Use of blackout dates, such as Christmas, New Years, and dates with major corridor activity,
  • Freeway lane closure limited to evening,
    • Sunday from 10:00 pm – 7:00 am
    • Monday through Friday from 7:00 pm – 7:00 am
  • Contractor assessed lane rental fees, and
  • Incentives for completing construction ahead of schedule.



slide 3: Identifying the Problems/Constraints

  1. Potential for queues during nighttime main lane closures
  2. Ramp, frontage road, and cross-street closures affecting local access
  3. Potential for multiple nighttime lane closures along corridor
    • Localized delays
    • Cumulative delays for through travelers
  4. Accelerated construction schedule
    • Limited coordination of lane closures
    • Lane closure locations constantly changing
    • ROW cross-section constantly changing

slide notes:

None




slide 4: Specifying User Needs

Issue Travelers Affected Information Needed
Nighttime freeway lane closures creating traffic queues and speed differentials All Real-time warning about downstream queue presence and location
Ramp, frontage road, and cross-street closures hindering local access and limiting traffic flow Local residents, regional travelers Access to closure information, "pushed" to those who want it
Freeway lane closures and incidents creating localized delays Local residents, regional travelers Current travel times on I-35
Multiple lane closures along corridor on same night causing significant delays to overall trip Regional, long-distance travelers Cumulative predicted delays to be encountered along I-35

slide notes:

Finally, TxDOT recognized that the possibility exists for longer-distance travelers on I-35 to encounter multiple delays due to the multiple projects active along I-35. A way to notify motorists about the combined delays of these projects on their trips was needed.




slide 5: System Requirements

  • Identification and tracking of planned lane closures
  • Current travel time monitoring
  • Forecasted travel conditions
  • End-of-queue notification
  • Information dissemination
    • Pre-trip, En-route
    • Email, Web, Social Media
  • Integration to existing traffic management centers
  • Operational and maintenance monitoring

slide notes:

System goals:

  • Create traveler information monitoring capability
  • Create work zone impacts assessments
  • Actively monitor planned closures
  • Create traveler information dissemination



slide 6: Identifying Alternatives

  • Standard TxDOT/contractor traveler information dissemination methods
  • Commercial-Off-The-Shelf (COTS) systems

✓ Customized solution involving the integration of technologies

Collage shows a notice that the driver is entering a work zone, a pole mounted traffic camera, and a dynamic message sign displaying 'no delay next 17 miles'

slide notes:

None




slide 7: Concept of Operations

Concept of Operations flow chart

slide notes:

None




slide 8: Systems Diagram

I-35 Traveler Information During Construction System Diagram

slide notes:

None




slide 9: System Design Components

  • Actively managed lane closure database (PCNS)

Screenshot of the lane closure database website

  • Automated analysis of potential impacts of lane closures (LCAS)

Screenshot of a queue and delay analysis table.  The highest expected and worst case queue/delay periods (during morning rush hour) are highlighted.

slide notes:

None




slide 10: Components (cont’d)

  • Bluetooth monitoring of current travel times over 2-5 mile segments
Pole mounted roadside Bluetooth reader powered by solar panels
  • Deployment of end–of–queue warning technology when and where needed (based on queue analysis)
Dynamic message sign displaying 'Stopped Traffic 2 Miles'

slide notes:

None




slide 11: Components (cont'd)


  • Advance notification of lane closure impacts
    • Up to 7 days out
    • Updated daily
  • Email and feed to TxDOT websites
  • Future corridor impacts under development
Screenshot of the I-35 Daily Closures website

slide notes:

None




slide 12: Components (cont'd)

  • Current travel times via PCMS
    • 21 signs
    • 7-10 mile spacing
  • Integrated with TxDOT LoneStar software
    • C2C communication
    • Allows TxDOT personnel to take over sign control
Dynamic message sign displaying 'Belton 10 Miles 9 Minutes'

slide notes:

  • Multiple vendors of signs
  • Some cities have multiple signs to that destination
  • ~ 10 mile spacings.



slide 13: Components (cont'd)

  • Hybrid forecasted delay signs
    • Targeting long-distance travelers en–route
    • Based on expected arrival times to queues
Forecasted delay sign indicating the travel time to the next towns on the corridor and a sample table of estimated delay by the time of day.

slide notes:

None




slide 14: Implementation/Procurement

  • Field monitoring devices procured and deployed through a contract with TTI
  • End-of-queue warning technology procured through project change orders
  • Corridor delay forecasting development and calibration continues
  • Corridor performance metrics development continues

slide notes:

None




slide 15: Evaluation – Lane closure notifications

  • 1100 email recipients
  • Usefulness
    • 81% useful
    • 91% easy to understand
    • 93% abbreviations easy to understand
    • 90% right amount of detail
  • Format:
    • 67% continue current
    • 33% customize for my location
    • Points to through nature of trips
Screenshot of the I-35 Daily Closures website

slide notes:

None




slide 16: Evaluation – Travel Times via PCMS

  • 91% had seen
  • 83% useful
  • 82% frequent enough
  • 92% agree with appropriateness of destination cities
Map of the I–35 corridor divided into travel data time collection sections

slide notes:

None




slide 17: Evaluation – Performance Metrics

Chart showing the distribution of I-35 main lane closures per night for 8 days excluding weekend black-out days. The data provided indicate the number of main lane closures per nightand the percentage of days with that number of main lane closures. Data are as follows: 0 Closures: 3.1 days, 14%; 1 Closures: 6.2 days, 27%; 2 Closures: 1 day, 5%; 3 Closures: 7.2 days, 32%; 4 Closures: 3.1 days, 14%; 5 Closures: 1 day, 5%; 6 Closures: 1 day, 5%.

slide notes:

None




slide 18: Performance Metrics (cont'd)

Chart of the Distribution of Advance Closure Notification Times

slide notes:

None




slide 19: Performance Metrics (cont'd)

Chart of the percent of lane closures with delay by project section

slide notes:

None




slide 20: Lessons learned

  • Balancing lane closure advance notification time versus accuracy is a challenge
  • Field infrastructure locations have to move quickly with phasing
    • Temporary deployments critical
    • Geolocate and track via GPS
  • BT spacing can go 5-8 miles in rural settings
  • Public does pay attention to real-time information, prefers specifics

slide notes:

None




slide 21: Lessons learned (Cont.)

  • Change ordering in technologies to existing projects continues to be a challenge
  • Ensuring good data exchange protocols is critical → XML

slide notes:

None




slide 22

Image shows the Texas DOT My Interstate 35 Logo

Questions?

slide notes:

None

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