slide1
Download
Skip this Video
Download Presentation
Major Transportation Corridor Studies Using an EMME/2 Travel Demand Forecasting Model: The Trans-Lake Washington Study

Loading in 2 Seconds...

play fullscreen
1 / 18

PowerPoint Presentation espindolae2kpresentation - PowerPoint PPT Presentation


  • 288 Views
  • Uploaded on

Major Transportation Corridor Studies Using an EMME/2 Travel Demand Forecasting Model: The Trans-Lake Washington Study. Carlos Espindola, Youssef Dehghani and Cathy Strombom Parsons Brinckerhoff, Inc. October 18-20, 2000

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'PowerPoint Presentation espindolae2kpresentation' - Angelica


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Major Transportation Corridor Studies Using an EMME/2 Travel Demand Forecasting Model: The Trans-Lake Washington Study

Carlos Espindola, Youssef Dehghani

and Cathy Strombom

Parsons Brinckerhoff, Inc.

October 18-20, 2000

15th Annual International EMME/2 Users’ Group Conference, Vancouver, BC.

outline
Outline
  • The Project
  • The Alternatives
  • Mini Validation
  • Coding Challenges
  • Problems Encountered
  • Measures of Effectiveness
  • Looking Ahead
  • Acknowledgements
the project
The Project
  • Identify “reasonable and feasible solutions” to improve mobility across/or around Lake Washington
  • Three facilities were studied: SR-520, I-90 and SR-522
  • Projected regional growth: 50% more person trips over the next 25 years
  • Using EMME/2 based four- step model (Puget Sound Regional Council)
the alternatives
The Alternatives
  • 6 alternatives plus No-Build
  • No-Build
    • SR-522: 2 GP lanes in each direction
    • SR-520: 2 GP lanes in each direction
    • I-90: 3 GP lanes plus 2 reversible center lanes
  • Metropolitan Transportation Plan (MTP, 1998)
    • bus-only lanes on SR-522
    • HOV lanes on SR-520
    • LRT on I-90 center lanes
    • some TDM improvements
the alternatives cont
The Alternatives (cont.)
  • MTP “Flipped”
    • new LRT bridge along SR-520
    • continuous 2-way HOV lanes on I-90 center lanes
  • Roadway/Rail
    • new LRT bridge along SR-520
    • LRT on I-90 center lanes
the alternatives cont7
The Alternatives (cont.)
  • New Crossings
    • a new four-lane arterial connection across the lake north of SR-520 and HOV lanes on SR-520
    • LRT on new arterial bridge and on I-90
  • Roadway/Bus
    • new four-lane freeway with HOV lanes
    • improved bus service & passenger only ferry
    • 2-way 24 hour HOV lanes on I-90 center lanes
the alternatives cont8
The Alternatives (cont.)
  • Maximize Alternatives
    • passenger-only ferry
    • conversion of one GP lane to HOV lane on SR-520
    • LRT on I-90 center lanes
    • very aggressive TDM package including congestion-pricing measures
mini validation
Mini Validation
  • Screenline comparison of vehicle volumes: observed vs. modeled
  • Tolerance: + 10%
  • Highway Assignment
    • Data: AWDT
    • Daily variation of traffic volumes
  • Transit Assignment
    • Data: observed and Sound Transit (ST) model
coding challenges
Coding Challenges
  • Transportation demand management
    • Equivalent parking cost
  • Congestion Pricing
    • Time equivalency of toll
problems encountered
Problems Encountered
  • The “flip-flop” effect
    • What? Large variation in number of trips across the lake (validation)
    • Why? Caused by congestion (constrained capacity) in Trans-Lake facilities
    • How? Trip distribution (gravity model) reduces trips across the lake – search for equilibrium between supply and demand
    • Then? Consistency in application from one alternative to another
congestion pricing
Congestion Pricing
  • Feasibility of tolls on cross lake trips (demand management)
  • Cross lake demand got depressed (“lost” over 100,000 daily trips)
    • caused unrealistic demand estimates for transit and HOVs
  • What to do?
    • Introduce toll on assignment only
    • Or two step process
congestion pricing cont
Congestion Pricing (cont.)
  • Two step process
    • Suppressed demand for non-HOVs
      • Model run with toll, lane conversion and parking costs
    • Un-suppressed demand for HOVs and transit
      • Model run without toll, lane conversion or parking costs
    • Highway and transit assignments
measures of effectiveness
Measures of Effectiveness
  • To help evaluate and compare the performance of the alternatives
    • Vehicle trips by facility and mode (NCPL, HOV and Commercial vehicles)
    • Person trips by facility and mode (same as above plus Transit), screenline mode shares were produced
    • Weighted average PM peak period travel time in minutes between designated districts
measures of effectiveness cont
Measures of Effectiveness (cont.)
  • From select link analysis on each facility:
    • PM peak period vehicle miles of travel (VMT)
    • PM peak period vehicle hours of travel (VHT)
    • PM peak period speeds
    • weighted average trip lengths both in distance and time
  • Peak period and hourly vehicular traffic, capacity and v/c ratio by facility and direction
  • Peak period person through-put by facility, mode and direction
looking ahead
Looking Ahead
  • Use of Composite Impedance in trip distribution to reflect both highway and transit improvements
  • Update base year (1998)
  • Define the use of “new” vs. current version of PSRC model
  • Look at better way to forecast 3+ HOVs
summary
Summary
  • A tool to identify “reasonable and feasible solutions” to improve mobility across/or around Lake Washington
  • Helps evaluate a wide variety of transportation improvements (focus on mode, location and amount of change)
acknowledgements
Acknowledgements
  • Washington State Department of Transportation – Office of Urban Mobility (WSDOT/OUM)
  • Puget Sound Regional Council (PSRC)
  • Trans-Lake Washington Consulting Team
ad