The Aggregate Rail Ridership Forecasting Model: Overview

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The Aggregate Rail Ridership Forecasting Model
Overview

• Dave Schmitt, AICP
• Southeast Florida Users Group
• November 14th 2008

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What is It?

• A sketch-planning tool consisting of CTPP 2000
  data, GIS info, programs, control files, and a
  spreadsheet collectively used to develop an
  estimate of the ridership potential for a new
  rail system
• Based on 20 recently-built light and commuter
  rail projects
• Two spreadsheets light rail and commuter rail
  all other materials are identical
• Sponsored by FTA developed by AECOM

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CTPP 2000 Data Part 1 Workers at home-end Part 2 Workers at work-end Part 3 Flows
CTPP1INC_TZ.exe, CTPP1INC_BG.exe, and CTPP1INC_TR.exe programs Calculates proportion of households in low, medium and high income categories by geographic unit
CTPP2EMP_TZ.exe, CTPP2EMP_BG.exe, and CTPP2EMP_TR.exe programs Calculates workers in each geographic unit and estimates employment density
CTPP3.exe program Helps to extract tract-level data from region- or state-wide files
GIS info Rail station points Proportion of tracts/zones within range of stations
RailMarket.exe program Calculates the number of workers who both live and work within particular distances of a rail station by income group and employment density category
Spreadsheet Records service variables and RailMarket results produces ridership potential estimate
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LRT Model Equation

• Total Weekday Unlinked Rail Trips
• Weekday Unlinked Drive Access to Work Rail
  Trips
• Weekday Unlinked Other Rail Trips
• Weekday Unlinked Drive Access to Work Rail Trips
  
• 0.030 CTPP PNR 6 -to-1 Mile JTW Flows (lt50K
  Den)
• 0.202 CTPP PNR 6 -to-1 Mile JTW Flows (gt50K
  Den)
• Weekday Unlinked Other (Non-Drive Access to Work)
  Rail Trips 0.395 CTPP 2 -to-1 Mile JTW Flows
  (lt50K Den)
• 0.445 CTPP 2 -to-1 Mile JTW Flows (gt50K Den)

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CR Model Equation

• Commuter Rail Weekday Unlinked Trips
• Nominal Ridership x Demand Adjustment Factor
• Nominal Ridership
• 0.069High Income CTPP PNR 6-to-1 JTW flows
• 0.041Medium Income CTPP PNR 6-to-1 JTW flows
  
• 0.151Low Income CTPP 2-to-1 JTW flows
• Demand Adjustment Factor (10.3Percent
  Deviation in Average System Speed) x
• (10.3Percent Deviation in Train Miles per
  Mile) x
• Rail Connection Index

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CR Model Equation (2)

• Percent Deviation in Average System Speed
• System Average Speed-35.7 mph / System
  Average Speed35.7)/2
• System Average Speed
• Annual Revenue Vehicle Miles/Annual Revenue
  Vehicle Hours
• Percent Deviation in Train Miles per Mile
• Weekday Train Miles per Directional Route
  Mile-10.3 /
• (Weekday Train Miles per Directional Route
  Mile10.3)/2
• Weekday Train Miles per Directional Route Mile
• Annual Revenue Vehicle Miles/250/Average Train
  Length

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• Applications

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Applications City A

• New rail line between CBD and suburban activity
  centers strong corridor bus ridership service
• Compared ARRF LRT model with travel demand model
  results
• Results
• ARRF LRT model results were 100 higher than
  travel demand model estimates
• Stronger motivation to investigate transit model
  parameters subsequently identified issues with
  walk- and auto-access connector methodology

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Applications City A (contd)

• Conclusions
• ARRF model may partially explain attractiveness
  of rail over existing bus service
• TDM path-builder probably better at evaluating
  bus/rail competition
• Equal service levels for bus rail
• Buses are just as close or closer to corridor
  activity centers

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Applications City B

• New rail line between CBD and suburban
  residential areas
• Used ARRF to develop rationale for
  alternative-specific constant
• Results on next slide

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Ridership Forecasts City B
Walk Drive/ Drop-Off Total
ARRF 14,794 6,548 21,342
TDM Model (no bias) 11,520 4,556 16,076
TDM Model (7.5 minute walk, 15 minute drive) 13,145 6,341 19,487
TDM Model (10 minute walk, 15 minute drive) 14,770 6,277 21,047
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Applications City C

• Streetcar in low density urban activity center
  existing service is local primarily captive
  market
• ARRF LRT model compared with travel demand model
  (2000 trip tables, 2030 networks)

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Applications City C (contd)

• Result
• Aggregate model forecast 120 higher than travel
  demand model
• Conclusion
• ARRF model may partially explain attractiveness
  of rail over existing service, but does not
  well-represent benefits of project since
• The project mode is different than calibrated
  mode
• Lack of choice market not consistent with LRT
  sample cities

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Applications City D

• Commuter rail between two adjacent metropolitan
  areas some express bus service to each CBD, but
  no service between CBDs
• Commuter rail ARRF model compared with travel
  demand model (2000 trip tables, 2030 networks)
  applied to each CBD

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Applications City D (contd)

• Result
• Aggregate model forecast 130 higher than travel
  demand model
• Conclusion
• ARRF model may partially explain attractiveness
  of rail over existing commuter bus service, but
  does not well-represent benefits of project since
  lack of service between CBDs unlike CR sample
  cities

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Applications City E

• New commuter rail line to high mode share CBD
  with established choice market commuter bus
  service from large park and ride facilities
• Commuter rail ARRF model compared with travel
  demand model (2000 trip tables, 2030 networks)
  applied

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Applications City E (contd)

• Result
• Aggregate model forecast 30 lower than travel
  demand model
• Conclusion
• Existing commuter (choice) market in corridor
  stronger than CR sample cities

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• Process

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General Procedure

1. Obtain basic input files
2. Determine the socio-economic characteristics of
   the geography
3. Prepare the CTPP Part 3 flow data
4. Determine the relationships between rail stations
   geography
5. Run RailMarket program to determine the number of
   work for both live work nearby rail stations
6. Enter the information from RailMarket into the
   model spreadsheet

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Station Buffers
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Spreadsheets
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Materials Available from FTA

• Detailed documentation
• Part-1 Model Application Guide
• Part-2 Input Data Development Guide
• Part-3 Model Calibration Report
• CTPP and RailMarket programs
• Spreadsheets LRT and CR
• Contact Nazrul.Islam_at_dot.gov

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• Thank you!