Work Zone Mobility and Safety Program

ITS Warrants and IWZ Research Project

slide 1: ITS Warrants and IWZ Research Project

Tina Roelofs
Enterprise Pooled Fund

May 21, 2013
Bettendorf, Iowa

slide 2: Agenda

  • ENTERPRISE Program
  • ITS Warrants Project
  • IWZ Research Project

slide 3: ENTERPRISE Program

Collage of sample ENTERPRISE Program documents, the ENTERPRISE Logo, and the full program name: Evaluating New TEchnologies for Road PRogram Initiatives in Safety and Efficienty.

slide 4: ENTERPRISE Program

  • Goals
    • Facilitate rapid progress in the development and deployment of ITS technologies
    • Accelerate the systematic advancement of selected ITS projects
      • Members carry out ITS projects and activities including fundamental research, technology development, demonstration, standardization and deployment

slide notes:


slide 5: ENTERPRISE Program


  • Arizona DOT
  • Georgia DOT
  • Idaho Transportation Department
  • Illinois DOT
  • Iowa DOT
  • Kansas DOT
  • Maricopa County, Arizona
  • Michigan DOT*
  • Minnesota DOT
  • Mississippi DOT
  • Oklahoma DOT
  • Texas DOT
  • Virginia DOT
  • Washington State DOT
  • Ontario Ministry of Transport
  • Transport Canada
  • Dutch Ministry of Transport
  • FHWA

* Michigan DOT administers program and is a founding member

slide 6: ITS Warrants Project

  • Project began in 2009
    • Need for an efficient and effective methodology to determine if ITS deployments are appropriate
  • Goals
    • Assist agencies with decisions about where to deploy ITS devices
      • Is a device warranted at a specific location?
      • Should further considerations be performed?
      • Eliminate locations where a device is not warranted
    • Validate locations of existing ITS device deployments

slide 7: ITS Warrants Project

  • Warrants have been developed for 10 devices
    • CCTV
    • Curve Warning System
    • DMS
    • Dynamic Speed Display Sign
    • HAR
    • Ramp Meter
    • RWIS
    • Variable Speed Limit
    • ITS Devices in Work Zones
    • ICWS (DRAFT)
  • Gathered input from
    • Interactive Website
    • ENTERPRISE Member States and Non-Member States
    • ITE Mid-Year Meeting
    • ITS Canada Workshop
    • TRB, ITS World Congress, ITS America Sessions

slide 8: ITS Warrants Project

  • Warrants Use
    • This is one tool to use in the decision making process
    • Series of 'yes' or 'no' questions that can be answered quickly, avoiding the complexity of collecting a lot of data before using the warrants
    • Warrants have been used for real world decision for ITS deployments by: ND, KS, MN, VA
      • VDOT has used the warrants as an initial screening tool for selecting RWIS deployments

slide 9: ITS Warrants Project

Image shows a flowchart for Dynamic Speed Display Sign Warrant Development

slide 10: ITS Warrants Project

Dynamic Speed Display Sign

  • Purpose 1: Transition Zones
  • Purpose 2: Posted Speed Adherence
  • Purpose 3: Intelligent Work Zones

Variable Speed Limits

  • Purpose 1: Maximize Capacity
  • Purpose 2: Safe Stopping Distances
  • Purpose 3: Safe Travel Speeds for Conditions
  • Purpose 4: Work Zones

A speed limit sign with a "your speed" indicator below.

slide 11: DSDS Warrant 3: IWZ

Purpose: To promote speed limit adherence in locations where posted speed have temporarily been reduced for construction, maintenance or other traffic control.

Device is warranted if:

  1. The work zone is currently in operation and observations suggest that the 85th percentile speed at a location within the work zone exceeds the posted speed limit by at least 5 mph.


  2. Workers will be located adjacent to the open traffic lane.


  3. Hazardous roadway conditions, such as a temporary unusually tight curve, or a rough road surface, requiring extra driving precaution.

Note: Signs tend to be most effective where there are two lanes or less in one direction of travel.

slide 12: ITS Warrants Project

Intelligent Work Zone Warrants
Collection of devices that warn travelers of various hazards associated with work zones.

An array of ITS Warrants.

slide 13: ITS Warrants Project

Screenshot of the ENTERPRISE Transportation Pooled Fund Study – Warrants for the Installation and Use of Technology Devices for Transportation Operations and Maintenance website.

slide 14: IWZ Research Project

  • Project Purpose
    • Document the best practices and lessons learned regarding IWZ technologies from various sources to draw conclusions about what approaches work best in what situations.
  • Project Focus:
    • Dynamic Merge
    • End of queue warning systems
    • Alternate Routes
    • Variable Speed Limits

A dynamic message sign indicating a merge 1.5 miles ahead.

slide 15: IWZ Research Project

  • 2013 Work Zone Test Bed to track
    • Locations of signs and sensors
    • Messages used on signs
    • Thresholds used to active sign messages
    • Adjustments made to configurations
    • Public outreach approach

slide 16: Minnesota Dynamic Late Merge System


  • Speeds < 20 mph (guide)
  • Vol. < 1500 v/hr. (guide)
  • Trend (reduced speeds & increased vol.)

  • DLM Messages
  • Late Merge Approach

Diagram illustrates the Minnesota Dynamic Late Merge System. A representation of a roadway on the approach to a work zone contains a series of signs on the approach indicating their possition and message as follows: Furthest from the lane closure: "Stopped Traffic Ahead / Use Both Lanes". Closer to the lane closure: "Merge Ahead / Use Both Lanes". At the lane closure: "Merge Here / Take Turns"

slide 17: Minnesota Dynamic Late Merge System


  • Speeds < 45 MPH (35)

  • DLM Messages
  • Late Merge Approach

Michigan Dynamic Late Merge System Diagram. A representation of a roadway on the approach to a work zone contains a series of signs on the approach indicating their possition and message as follows: Furthest from the lane closure: "Stopped Traffic Ahead / Use Both Lanes". Closer to the lane closure: "Use Both Lanes / Stay in Your Lane". At the lane closure: "Take Your Turn / Merge Here"

slide 18: IWZ Research Project 2013 Projects to Track

  • Dynamic Merge
    • EB I-96 near MM 9 in Ottawa County (Michigan)
    • MnDOT SP 2772–96 – Hwy 169 (Minnesota)
  • Queue Warning System
    • End of Queue Warning System on I-35 (Texas)
    • Congestion Warning Milwaukee Area (Wisconsin)
    • Queue Warning in Jefferson County (Missouri)
  • Alternate Routes
    • Travel Time System (Wisconsin)
    • I-94 Travel Time System (Minnesota)
    • Metro Wide Detection System (Minnesota)
    • Travel Time and Alternate Route System – Effingham County (Illinois)
  • Variable Speed Limits

slide 19: Contact

Bill Legg, WSDOT
ENTERPRISE Chair and ITS Warrants Project Champion

Tina Roelofs
Athey Creek Consultants

Mark Johnson, TXDOT
ENTERPRISE IWZ Project Champion

Return to List of Presentations
Office of Operations