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Project Meeting 2023.09.07
Michelle Bina edited this page Sep 12, 2023
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- TransLink / ActivitySim Discussion
- Introductions
- TransLink ABM development goals and plans
- ActivitySim Consortium & Project Management
- ActvitySim Development
- ActivitySim implementation
- TransLink Introduction
- Hope is to move from trip-based to ABM in order to respond to more policy questions being asked. Canada has a different regulatory framework. They don’t have to answer some of the questions that are driving ABM development in US, like equity and individual-based characteristics, EJ analyses, etc. However, they would now like to drill down to the individual level. Examples of policy questions include:
- Interested in time-of-day travel impacts, pricing studies for example (trip-based model has static time of day assumptions).
- Recent changes in travel behavior further solidify their desire to move to an ABM, but wasn’t an initial driver.
- Evaluated several platforms. Interested in ActivitySim for several reasons:
- Implemented in python/pandas, language that many students are learning allows for the best chance to have internal capacity to change the model for future iterations.
- There is a community of users that they could connect with
- Current implementation involves adapting a donor model (SEMCOG) and then updating with their recent survey data
- Started a few years ago by setting up a synthetic population with PopulationSim
- Using SEMCOG to start up a version of the model, Version 0, to understand the basic syntax, the data flows, requirements, get it working, etc. (6-9 months there)
- Phase 1, started last September, aimed to make the model their own by estimating components with their survey data (spent a lot of time processing their data) and working with RSG to help them avoid common pitfalls.
- Starting this fall, they will be working on calibration/validation.
- Overall experience – what worked/what didn’t?
- There’s was a pretty steep learning curve
- Liked using estimation mode
- Benefited from the data pipeline that feeds start to finish
- Troubles so far include memory issues, some bug fixing
- Hope is to move from trip-based to ABM in order to respond to more policy questions being asked. Canada has a different regulatory framework. They don’t have to answer some of the questions that are driving ABM development in US, like equity and individual-based characteristics, EJ analyses, etc. However, they would now like to drill down to the individual level. Examples of policy questions include:
- ActivitySim Intro
- Currently have 11 member agencies, hopefully adding in another one next year
- Joe provided an overview of mission and administrative activities
- Joe provided an overview of current activities: roadmap, performance, and documentation
- Questions from TransLink
- TransLink understands there’s lots of technical discussion and proficiency but wanted to know more about how we address model maintenance. Joe discussed our reserved funds for addressing potential bugs, as they are revealed, differentiating between issues with the main code versus specific implementations.
- Are there any issues/barriers for international member?
- An Australian member will be joining shortly. Since contracting is through AMPO, to AMPO’s knowledge, there are no limitations or barriers for international agencies.
- Next Steps
- Inviting TransLink to member agency-only meetings to understand the collective decision-making process and our short- and long-term vision.