Work Zone Mobility and Safety Program

Development of Traffic Information Systems Using DSRC Technology for the Work-Zone Environment

slide 1: Development of Traffic Information Systems Using DSRC Technology for the Work-Zone Environment


Imran Hayee
Department of Electrical and Computer Engineering University of Minnesota Duluth

May 8, 2013

slide notes:

None.



slide 2: Idea of Connected Vehicles


Mission: Intelligent Transportation Systems (ITS)

Objectives: Safety, Mobility and Efficiency

Diagram illustrating all the ways and means by which connected vehicles will communicate with each other, the infrastructure, and drivers.

slide notes:

None.



slide 3: Outline


  • Introduction
    • DSRC Technology Overview
    • Applications
    • Work Zone Environment
  • V2I Traffic Information System
    • System Architecture and Design
    • Field Demonstration
  • V2V Assisted V2I System
    • System Architecture and Design
    • V2V Protocol
    • Field Demonstration
  • VMS Integration
    • Need
    • Demonstration
  • V2V System – Ongoing Work
  • Summary / Questions

slide notes:

None.



slide 4: DSRC Technology Overview


A short to medium range wireless communications protocol specifically designed for automotive use to promote traffic safety, efficiency and mobility. It incorporates both Vehicle to Infrastructure (V2I) and Vehicle to Vehicle (V2V) communication.

Artist's rendering of vehicles communicating among themselves and with the infrastructure at an urban signalized intersection.

Technical Specifications:

  • 5.9 GHz
  • Range up to 1000 meters
  • Data rate 6 to 27 mbps
  • 7 licensed channels
  • Vehicle speed up to 100MPH

slide notes:

IEEE 802.11p will be used as the groundwork for Dedicated Short Range Communications (DSRC) Refers to both the technology and protocols The spectrum was allocated for safety purposes, but it allowed unused bandwidth to be available for other applications, such as mobility or convenience

slide 5: DSRC Potential Applications


  • Traffic Information Systems
  • Emergency Vehicle Signal Preemption
  • Approaching emergency vehicle warning
  • Weather and road conditions warning
  • Curve speed warning
  • Do not pass warnings
  • Cooperative Adaptive Cruise Control
  • Cooperative Forward Collision Warning
  • Left Turn Assist
  • Merge Assist

slide notes:

  • Transit or emergency vehicle signal priority
  • Electronic parking payments
  • Commercial vehicle clearance and safety inspections
  • In-vehicle signing
  • Rollover warning
  • Probe data collection
  • Highway-rail intersection warning


slide 6: Obstacles to Adoption of DSRC Technology


  • The Chicken and Egg Dilemma
  • Market Penetration
  • Infrastructure Support

Simple flow diagram shows how the original vehicile infrastructure integration (VII) vision of safety and mobility through wireless technology was broken down by safefty applications and mobility applications. The three dilemmas each bundle of applications faced moving forward were vehicles or infrastructure first? fast fleet penetration? or infrastructure deployment? The vision of VII over time changed to become the IntelliDrive vision, whose vision remained safety and mobility through wireless technology.

slide notes:

Answering the dilemma of which comes first – vehicles or infrastructure – could hinge on a NTHSA regulatory decision in 2013 about whether to require technology on new vehicles.



slide 7: Work Zone Environment


Collage of photos featuring work zones and congestion.

slide notes:

None.



slide 8: Total Work Zone Related Fatalities


Year Work Zone Related Fatalities
2011 587
2010 576
2009 680
2008 720
2007 831
2006 1,004
Source: Fatality Analysis Reporting System (FARS) – Final, NHTSA

slide notes:

None.



slide 9: Current Approach to Reduce Fatalities


  • Estimate travel time and communicate to the drivers

A portable changeable message sign on the side of a congested highway advises drivers that it would be 40 minutes to the end of the work zone.

slide notes:

None.



slide 10: Outline


  • Introduction
    • DSRC Technology Overview
    • Applications
    • Work Zone Environment
  • V2I Traffic Information System
    • System Architecture and Design
    • Field Demonstration
  • V2V Assisted V2I System
    • System Architecture and Design
    • V2V Protocol
    • Field Demonstration
  • VMS Integration
    • Need
    • Demonstration
  • V2V System – Ongoing Work
  • Summary / Questions

slide notes:

None.



slide 11: Student In Action


Collage of students working on research activities.

slide notes:

None.



slide 12: V2I System Architecture


  • RSU is placed such that RSU monitoring range aligns with the end of the congestion.
  • At periodic intervals, an OBU participation is requested by the RSU to monitor a vehicle's speed and position through a congestion area.
  • RSU sends traffic alert message to all OBUs indicating travel time through monitoring area.

Diagram represents functions of the V2I system architecture. Diagram depicts a roadway with a work zone and identifies the locations of DSRC RSU, RSU coverage zone, start and end locations of congestion zone, and monitoring range.

slide notes:

None.



slide 13: Field Demonstration


  • The field demonstration site was chosen at Rice Lake Rd, Duluth MN with the focus on providing a clear line of sight between RSU and the OBU.
  • The RSU is placed near the congestion end due to reduced range on one side due to signal blocking by back of the vehicle.

Satellite photo of the field demonstration site with labels indicating the start of the RSU monitoring range, start of congestion, end of congestion, and end of RSU monitoring range.

slide notes:

None.



slide 14: Results – Traffic Safety Parameters


The traffic parameters – Start of Congestion location and the Travel Time are determined by RSU and communicated to all the OBUs in range

Side-by-side graphs chart speeds over a distance of 750 meters and a period of 180 seconds.

slide notes:

None.



slide 15: Varying the Length and Depth of Congestion


Congestion scenarios of varying start of congestion location and congestion depth were tested for different vehicle speeds

Side-by-side graphs chart speeds over a distance of 800 meters.

slide notes:

None.



slide 16: Outline


  • Introduction
    • DSRC Technology Overview
    • Applications
    • Work Zone Environment
  • V2I Traffic Information System
    • System Architecture and Design
    • Field Demonstration
  • V2V Assisted V2I System
    • System Architecture and Design
    • V2V Protocol
    • Field Demonstration
  • VMS Integration
    • Need
    • Demonstration
  • V2V System – Ongoing Work
  • Summary / Questions

slide notes:

None.



slide 17: V2V-Assisted V2I System


Conceptual diagram of a V2V assisted system in which vehicles communicate with each other and the DSRC RSU about congestion associated with a work zone.

slide notes:

None.



slide 18: V2V Message Relaying


  • Increased message broadcast range using V2V-assisted DSRC communication.
  • Much longer congestion coverage beyond the access range of one portable roadside DSRC unit.

Conceptual diagram of V2V message relaying process in which vehicles communicate with each other and the DSRC RSU about congestion associated with a work zone. When vehicles communicate with each other as well as the DSRC RSU, message broadcast range is increased.

slide notes:

None.



slide 19: V2V Message Relaying


  • Selective Relay
  • Directive Relay
Conceptual diagram of V2V message relaying process in which vehicles communicate with each other and the DSRC RSU about congestion associated with a work zone. The system uses both selective and directive relay.

slide notes:

None.



slide 20: Selective Relay


  • Only one of the vehicles should relay the message forward.
  • Selection should be such that the number of hops can be minimized.

Diagram comprised of two series of concentric circles. One is positioned over the RSU device, the other is positioned over a hypothetical vehicle on teh roadway approaching a work zone. In each case, the ring closest to the center is labeled tb1 and each expanding ring is labeled consecutively tb2 through tb5. A legend indicates that tb5 is less than tb4 is less than tb3, etc.

slide notes:

None.



slide 21: Directive Relay


  • Message should be relayed towards the direction of the road from which the vehicles are approaching towards the congestion.

In this diagram, a series of dots with circles around them represent vehicles. Before the first vehicle is an RSU and slightly behond that is a point labeled angular region focus point. Between each vehicle there is a dashed line with an arrow pointing to the vehicle behind it. At the first cross road, there is an angular region check elimination, and at the second cross road there is a reference angle check elimination.

slide notes:

None.



slide 22: Field Demonstration Setup – V2V


  • The field demonstration site was chosen at Rice Lake Rd, Duluth MN with the focus on providing a clear line of sight between RSU and the OBU.
  • The RSU is placed nearer to the congestion end due to reduced range on one side from the signal being blocked.

Combination google map and diagram depicting demonstration site. Labels indicate the positions of four vehicles with onboard units, the starting location of congestion (varying), the ending location of congestion, the RSU location, and the end of the monitoring range.

slide notes:

None.



slide 23: Results


  • Increased congestion coverage range
  • Increased message broadcast range

Two graphs chart speeds over a distance of 2000 meters and a time period of 400 seconds.

slide notes:

None.



slide 24: Outline


  • Introduction
    • DSRC Technology Overview
    • Applications
    • Work Zone Environment
  • V2I Traffic Information System
    • System Architecture and Design
    • Field Demonstration
  • V2V Assisted V2I System
    • System Architecture and Design
    • V2V Protocol
    • Field Demonstration
  • VMS Integration
    • Need
    • Demonstration
  • V2V System – Ongoing Work
  • Summary / Questions

slide notes:

None.



slide 25: Need for Variable Message Sign (VMS) Integration with the Developed System


Conceptual diagram of V2V message relaying process in which vehicles communicate with each other and the DSRC RSU about congestion associated with a work zone. Two labels on the diagram read "Not all vehicles will be DSRC equipped in the initial deployment phase." and "What market penetration is needed for this system to acquire travel parameters."

slide notes:

None.



slide 26: DSRC Market Penetration Rate Requirement Analysis


  • Analysis suggests that successful functionality:
    • Requires a minimum DSRC penetration rate of 35% during non-rush hour traffic situation.
    • Requires a minimum DSRC penetration rate of 20% during rush-hour traffic situation.

Collage of images in which a graph illustrates how flow equals speed times density, a graph charts the Poisson Distribution bell curve, a photo illustrates light traffic flow and density, a graph charts uniform distribution, and a photo illustrates heavy traffic flow and density.

slide notes:

None.



slide 27: Acquisition vs. Dissemination


Conceptual diagram of V2V message relaying process in which vehicles communicate with each other and the DSRC RSU and with DSRC equipped variable message signs about congestion associated with a work zone. The variable message signs in turn display appropriate messages warning drivers of work zone conditions. Labels on the diagram read "How to communicate travel parameters to the vehicles lacking DSRC capability?" and "DSRC equipped VMS is the answer, but requires a DSRC-VMS interface."

slide notes:

None.



slide 28: DSRC – VMS Interface Design


Diagram indicates the connections among a DSRC-VMS interface design and the actions taken by each element.

slide notes:

None.



slide 29: DSRC – VMS Interface Demonstration


Conceptual diagram of V2V message relaying process in which vehicles communicate with each other and the DSRC RSU and with DSRC equipped variable message signs about congestion associated with a work zone. Two photos of VMS laid alongside the diagram display the messages " Caution Work Zone" and "Travel Time 32 Minutes".

slide notes:

None.



slide 30: Outline


  • Introduction
    • DSRC Technology Overview
    • Applications
    • Work Zone Environment
  • V2I Traffic Information System
    • System Architecture and Design
    • Field Demonstration
  • V2V Assisted V2I System
    • System Architecture and Design
    • V2V Protocol
    • Field Demonstration
  • VMS Integration
    • Need
    • Demonstration
  • V2V System – Ongoing Work
  • Summary / Questions

slide notes:

None.



slide 31: Current Work


Combination of three diagrams epicting the concept of the V2I system, in which vehicles communicate one way with the infrastructure; in which V2V systems communicate with each other, with the DSRC-RSU, and with variable message sign displays;  and in which V2V systems communicate solely with variable message signs but not with the DSRC-RSU.

slide notes:

None.



slide 32: Proposed System Architecture with Only V2V Communication


Diagram depicts the architecture of a V2V only communications system. In this diagram, DSRC equipped vehicles communicate congestion or slow downs on the approach to a work zone to following vehicles when triggering conditions are met at the beginning of the congested area in advance of the work zone.

slide notes:

None.



slide 33: Outline


  • Introduction
    • DSRC Technology Overview
    • Applications
    • Work Zone Environment
  • V2I Traffic Information System
    • System Architecture and Design
    • Field Demonstration
  • V2V Assisted V2I System
    • System Architecture and Design
    • V2V Protocol
    • Field Demonstration
  • VMS Integration
    • Need
    • Demonstration
  • V2V System – Ongoing Work
  • Summary / Questions

slide notes:

None.

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