MiltonMadison BiState Travel Demand Model

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Milton-Madison Bi-State Travel Demand Model

• Rob Bostrom
• Planning Application Conference
• Houston, Texas
• May 19, 2009

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Presentation Overview

• Milton-Madison Project Overview
• Bi-state model development
• Model Results
• Corridor study traffic forecasts

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Milton-Madison Project Overview

• Location existing US 421 bridge over the Ohio
  River at Milton, KY and Madison, IN
• Project Goals
• 5.3 M project to look at bridge replacement and
  rehabilitation options
• Possible funding using tolls
• Examination of I-71 to I-74 corridor necessitated
  the creation of a bi-state model using the
  Kentucky and Indiana statewide models

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Bridge Location
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(No Transcript)
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Bridge Characteristics

• Built in 1929, rehabilitated in 1997 (deck
  replacement, structural steel repairs and
  concrete patching)
• 3,181 feet long, steel truss w/ 10-ft lanes
  (substandard)
• Current ADT is 10,700
• Truck percentage is 4
• Temporary 15-ton weight limit

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Needs Deficiencies Report

• Extensive data collection
• OD survey
• Historical data review
• Blanket counts including turning movement counts
  around area

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Bi-State Model

• Purpose
• Source data
• Network development
• Zone system development
• Trip table development
• Traffic assignment
• Forecasting procedures

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Bi-state model development

• Purpose
• Use for bridge replacement alternatives (in
  vicinity of Madison)
• Use to determine if new bridge would create
  demand in I-71 to I-74 corridor
• Model data sources
• KY statewide travel demand model and IN statewide
  travel demand model
• Field data including O-D surveys and traffic
  counts
• KY CIMS and IN Commodity flow database for
  commodity flows

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KYSTM Background

• Base Year 2007
• Future Year 2030
• 4870 TAZs, including 3651 in-state TAZs
• 71640 Network links including 55662 in-state
  links
• Developed in 2003 by WSA
• Revalidated in 2007 by KYTC

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INSTM Background

• Base Year 2000
• Future Year 2030
• 4720 TAZs, including 4579 in-state TAZs
• 45468 Network links including 32304 in-state
  links
• Developed in 2003 by BLA

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Combining Networks
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Combining Networks
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Combining Networks

• Converting INSTM network attributes to KY format

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TAZ Development

• Necessary to update INSTM base year from 2000 to
  2007.
• The key data needed was population, households
  and employment
• Data was interpolated between the base year and
  the 2030 future year
• The county and state control totals were compared
  to Woods and Poole 2007 data as a reasonableness
  check
• The resulting data for Jefferson County (the
  Indiana county in which the bridge is located)

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Consolidated TAZs
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TAZs

• Also had to change the zone numbering scheme as
  follows
• Original numbering scheme
• New numbering scheme

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Trip table development

• KYSTM generates trip tables for the following
  purposes
• Short distance Private Occupancy Vehicles (POV)
  HBW, HBO, NHB
• Long distance Private Occupancy Vehicles
  Business, tourist, other long distance
• Trucks long distance trucks, local trucks
• INSTM generates trip tables for the following
  purposes
• Short distance Private Occupancy Vehicles (POV)
  HBW, HBO, NHB
• Long distance Private Occupancy Vehicles
• Trucks

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Trip table disaggregation

• KY long distance trips need to be disaggregated
  for POV, LD and Truck trips
• Factors were developed to transform the KY TAZs
  to the INSTM TAZs. An example of the factors for
  a single KYSTM zone is shown below

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External Special Generator Trip Table
Disaggregation

• KYSTM only validated within KY
• External trips (outside KY) were treated as
  special generators
• Used INSTM to distribute special generators,
  especially 600013 (Ext Sta on US 421 bridge)

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Final Bi-state model triptable

• Short distance Private Occupancy Vehicles (POV)
• KYSTM Home Based Work (HBW)
• KYSTM Home Based Other (HBO)
• KYSTM Non Home Based (NHB)
• INSTM Home Based Work (HBW)
• INSTM Home Based Other (HBO)
• INSTM Non Home Based (NHB)
• Long distance Private Occupancy Vehicles
• KYSTM Business
• KYSTM Tourist
• KYSTM Other long distance
• INSTM Long distance
• Trucks
• KYSTM Trucks
• INSTM Trucks

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Assignment

• AON Trucks Use an All or Nothing assignment
  method to Assign KYSTM Trucks and INSTM Trucks
  together
• Preload Trucks
• UE for POV use a user equilibrium method to
  assign all private occupancy vehicles together

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Validation

• Visual review of the number of lanes and network
  connectivity
• Shortest path traffic assignments to ensure that
  no breaks in the network existed
• Review of the output travel times between traffic
  analysis zones, to ensure that there were no
  unreasonable travel times caused by network
  coding errors

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Validation

• Validated only for Jefferson County (containing
  Madison)
• Used RMSE and maximum percent deviation (NCHRP
  255) comparisons
• Bridge assignment was 10,200 compared to 10,300
  actual count

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Actual counts vs. modeled volumes
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O-D Comparison

• WSA performed OD data collection in Madison
• Performed select link analysis to compare
• Model seems reasonable although there are no
  standards for OD comparison

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Future Model

• Both IN DOT KYTC provided their EC networks
• Used 2030 as the forecast year
• Looked at No-Build conditions
• Future growth shown below

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Model Results

• Milton-Madison bridge
• 2030 volume 12,900 (25 increase)
• Select link analysis for trips using bridge shown
  below

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Distribution of Bridge Trips
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Forecasted volumes POV Truck
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Forecasted 2007-2030 Change
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Corridor Study Analysis

• Purpose of corridor study to see if combination
  of new Ohio River Bridge and improved corridor
  results in substantial new traffic
• The alternatives analyzed were
• No Build
• Remove the bridge
• I-71 to I-74 on three different corridors
  crossing the Ohio River in the vicinity of
  Madison Milton

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Corridor Study Map
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Corridor Study Results

• Additional trips
• Total volume 5,000 to 6,000
• Trucks 1,000 to 1,500

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Corridor PMs

• The usual Performance Measures (PMs) were
  produced by the model
• 2030 daily vehicle miles traveled (VMT)
• 2030 daily vehicle hours traveled (VHT)
• The PMs were compared to the No Build alternative

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Conclusions

• Need for new tool Milton-Madison bridge project a
  major investment study needing refined modeling
  tools
• Project solution was a Bi-state model This tool,
  created from the KYSTM and INSTM was relatively
  easy to create and validate
• Successful implementation The Bi-state model
  results provided valuable information to
  decision-makers for future bridge volumes and for
  possible corridor options

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Thank You

• Questions?
• Rob Bostrom, rbostrom_at_wilbursmith.com