Milton-Madison Bi-State Travel Demand Model Rob Bostrom Planning Application Conference Houston, Texas May 19, 2009

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

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

Bridge Location

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

Needs & Deficiencies Report Extensive data collection –OD survey –Historical data review –Blanket counts including turning movement counts around area

Bi-State Model Purpose Source data Network development Zone system development Trip table development Traffic assignment Forecasting procedures

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

KYSTM Background Base Year = 2007 Future Year = TAZs, including 3651 in-state TAZs Network links including in- state links Developed in 2003 by WSA Revalidated in 2007 by KYTC

INSTM Background Base Year = 2000 Future Year = TAZs, including 4579 in- state TAZs Network links including in- state links Developed in 2003 by BLA

Combining Networks

Converting INSTM network attributes to KY format

TAZ Development Necessary to update INSTM base year from 2000 to –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)

Consolidated TAZs

TAZs Also had to change the zone numbering scheme as follows: –Original numbering scheme: –New numbering scheme:

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

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:

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 (Ext Sta on US 421 bridge)

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

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

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

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

Actual counts vs. modeled volumes

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

Future Model Both IN DOT & KYTC provided their E+C networks Used 2030 as the forecast year Looked at No-Build conditions Future growth shown below:

Model Results Milton-Madison bridge –2030 volume = 12,900 (25% increase) –Select link analysis for trips using bridge shown below

Distribution of Bridge Trips

Forecasted volumes: POV & Truck

Forecasted Change

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

Corridor Study Map

Corridor Study Results Additional trips –Total volume: 5,000 to 6,000 –Trucks: 1,000 to 1,500

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

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

Thank You Questions? Rob Bostrom,