Algorithm for Priority Based Lane Management

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Algorithm for Priority Based Lane Management

• Work by Ilya Tabakh Tyler Stransky
• Presenter Ilya Tabakh

12/12/2006
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Outline

• Introduction
• Background
• Preliminary Quantification
• Protocol Design
• Future Work

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Outline

• Introduction
• Background
• Preliminary Quantification
• Protocol Design
• Future Work

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Introduction

• Project Deals with an algorithm to handle issues
  in using managed lanes
• Goal is efficient utilization of existing
  resources
• HOV are among the most prevalent managed lanes.
  Natural place to start.

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Outline

• Introduction
• Background
• Preliminary Quantification
• Protocol Design
• Future Work

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Background

• Congestion is Increasing

Weekday Peak-Period Congestion Has Grown in
Several Ways in the Past 20 Years in Our Largest
Cities
Congestion Has Grown Substantially in U.S. Cities
Over the Past 20 Years
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Background

• Managed Lanes

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Background

• Managed Lanes

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Background

• Available simulation environments
• NS-2 3
• No concept of physical traffic network
• Discrete event simulator
• Not a production simulator
• CORSIM 4
• Can simulate a network consisting of street as
  well as freeway traffic
• Reports on MOEs (Measures of Effectiveness, ie
  Average Network Speed)

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Outline

• Introduction
• Background
• Preliminary Quantification
• Protocol Design
• Future Work

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Preliminary Quantification
Various properties of the network are specified
here vehicle flow carpools cheaters
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Preliminary Quantification

• Queuing in Simulation (Gridlock)

Q Queuing NQ No Queuing
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Preliminary Quantification

• Freeway
• Average speed and ratio of move/total is
  proportional to car pool
• Bus performance is decreased slightly (no
  preemption)
• Street
• Results are similar
• In street scenario bus dwells in active lane

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Outline

• Introduction
• Background
• Preliminary Quantification
• Protocol Design
• Future Work

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Protocol Design

• Assumption
• All vehicles are equipped with GPS
• Provides the following
• Direction
• Speed
• Location
• Vehicles have sufficient performance to do
  signatures and communication in sub human
  reaction time scale

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Protocol Design

• Consideration for Bus (High Priority)
• Transmits a bus coming message
• Need to be able to sign message
• Provide location and heading

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Protocol Design

• Bus Protocol Component

Contains Location, Velocity and signature
Send Message
Receive ACK(s)
Warn Driver when necessary
If vehicle will not leave lane take picture
Contains Location and Velocity
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Protocol Design

• Consideration for Car (Low Priority)
• Need to know if in Managed Lane
• Need to be able to authenticate bus

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Protocol Design

• Car Protocol Component

Receive and Authenticate Message
Send ACK(s) until lane is vacated
Identify lane
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Listen for messages
If Bus within range warn driver
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Protocol Design

• Qualitative Overhead analysis
• Going the speed limit (65 MPH) a car is moving
  about 96 ft/sec
• Human driving reaction time is on the order of 1
  second
• The assumption that was made is not unreasonable

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Outline

• Introduction
• Background
• Preliminary Quantification
• Protocol Design
• Future Work

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Future Work

• Simulate network along with physical traffic
• Perform simulation with priority preemption of
  vehicles
• Account for number of passengers in HOV vehicles

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Questions!?!?
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References

• 1 FHWA Traffic Congestion and Reliability
  Trends and Advanced Strategies for
• Congestion Mitigation
• 2 Managed Lanes Handbook
• http//tti.tamu.edu/documents/0-4160-24.pdf
• 3 The Network Simulator - ns-2
• http//www.isi.edu/nsnam/ns/
• 4 McTrans TSIS
• http//mctrans.ce.ufl.edu/featured/TSIS/