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Focus Model Overview

Focus Model Overview. Denver Regional Council of Governments June 24, 2011. This presentation. Ask Erik, Shahida and me questions throughout General Concepts Break model into four “stages” Then several steps within each stage Describe each step- it’s inputs and outputs

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Focus Model Overview

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  1. Focus Model Overview Denver Regional Council of Governments June 24, 2011

  2. This presentation • Ask Erik, Shahida and me questions throughout • General Concepts • Break model into four “stages” • Then several steps within each stage • Describe each step- it’s inputs and outputs • Review stage inputs and outputs • Move onto to next stage

  3. General Concept 1:What is a logit model? 2 minute version • A model that calculates the utility of each choice from a set of discrete choices for a decision maker based on characteristics of the choice and the decision maker • Suppose we have a trip we know is 3 miles long, it’s purpose is to eat a meal, it’s final location is the CBD, the person who made the trip is age 68, the person’s income is $28,000/year. What is the utility for this trip for various travel modes? • We calculate the utility of taking transit for example based on the above information and the cost of transit, the time on transit, etc

  4. General Concept 1: Logit Models • Many types: we use multinomial logit and nested logit • Outcome is a simple closed form probability (not the choice) The choice must be randomly selected using a montecarlo process. • Anything to add? • Questions?

  5. General Concept 2:Monte Carlo Simulation • If model only assign probabilities to a choice, how do we get a choice • Monte carlo simulation • Suppose you have three choices, one with probability 0.1, one with probably 0.4 and one with probability 0.5. • Arbitarily, you assign choice one the range on the number line from 0 to 0.1 to choice one, from 0.1 to 0.5 to choice two and 0.5 to 1 to choice three. • Then you generate a pseudo-random number from 0 to 1. • If the number lands on the range assigned to the choice: you pick that choice • For example, if you generate the number 0.6784536475, you would select choice 3

  6. General Concept 3: Tours and Trips HOME WORK Outbound, Away From Home Tour Half Inbound, toward home tour half STORE • TOUR-BASED MODEL • 1 home-based work tour • 1 shopping stop • TRIP-BASED MODEL • 1 home-based work trip • 1 non-home-based trip • 1 home-based non work trip

  7. General Concept 4:Focus Model Flow: “Four” Steps FEEDBACK

  8. General Concept 5:Mechanics: Code Types used in Model

  9. General Concept 6: Use of SQL Server

  10. Households, Persons and Points in SQL Server

  11. Persons, Trips, and Tours in SQL Server

  12. General Concept 7:GISDK: OldModel Highway Network Inputs Transit Network Inputs Socio-economic Inputs Network Processing & Data Preparation Area Type Trip Generation Highway Skimming Transit Skimming Trip Distribution Parking Cost Mode Choice Time-of-Day Highway Assignment Transit Assignment

  13. General Concept 8:Why are we doing this anyway? • Data on ANY geography: all data is at a point level • Using Most Demographic Characteristics of People • Walking, biking, and transit • Vehicle Miles Traveled households in LoDo in 2035 • Average Bike Miles per persons age 70+ years old in 2020 • Number of Cars owned by college students attending CU Boulder in 2015 • Average Distance to Work by Restaurant Workers

  14. Review of General Concepts • 1. Logit Models are models that make assign probabilities to a set of choices for an individual from a list of discrete choices. • 2. The actual choice is made using a montecarlo process. • 3. Travel in the model is made on a tour-level, and then a trip level. • 4. We can divide the model into four stages. • 5. We use four types of code in the model: T-SQL, C#, GISDK, and Java. • 6. Much of the input and output data is stored in SQL Server. • 7. We still have to run parts of our old GISDK code for path building, skimming and assignment. • 8. We are doing this because we can get much finer detail and answer planning questions better using the model.

  15. Thinking points before we dive into the steps • How is the new model activity-based? How is it disaggregate? • How does the model actually do all this crazy stuff? • How is the old model different than the new model? • How does the model STILL simplify actual human behavior?

  16. Focus Model Flow: 28 Steps Outside The Speed Feedback Loop: Run Once- STAGE 1 GISDK called from C#: GISDK Preprocess Java: 3. Population Synthesizer C# 4. PopSyn Output Processor 5. Size Sum Variable Calculator STAGE 2 GISDK called from C#: For DIA, I-E, E-E and Commercial Trips 1. DRCOG Multi-Period Highway Preprocess 2. DRCOG Multi-Period Transit Preprocess 3. DRCOG Transit Preprocess 4. Trip Generation 5. Highway and Transit Skimming 6. Trip Distribution 7. Mode Choice STAGE 3 C# Regular Trips 8. Regular Work Location Choice 19 . Tour Main Mode Choice 9. Regular School Location Choice 20. Tour Time of Day Choice 10. Auto Availability 21. Intermediate Stop Generation 11. Aggregate Logsum Generation 22. Trip Time of Day Simulation 12.Daily Activity Pattern 23. Trip Time Copier 13. Exact Number of Tours 24. Intermediate Stop Location 14.Work Tour Destination Type 25. Trip Mode Choice 15.Work-Based Subtour Generation 26. Trip Time of Day Choice 16. Tour Time of Day Simulation 27. Write Trips to TransCAD 17. Tour Primary Destination Choice 18. Tour Priority Assignment STAGE 4 GISDK called from C#: 28. Highway and Transit Assignment FEEDBACK

  17. User Interface: How the steps look

  18. Focus Model Flow: Stage 1 FEEDBACK

  19. STAGE 1: Make Population and Network • Java: Population Synthesizer • C# to process in database: Size Sum Variable Calculator; PopSyn Output Processor • GISDK called from C#: GISDK Preprocess Creating networks for example

  20. Population Synthesizer ACS or PUMS Disaggregate Data Aggregate Data that We Need to Match: Economic Forecasts, Land Use Forecasts Disaggregate Population With the Right Portions Matching the Economic and Land Use Forecasts Questions?

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