TRANSIMS Research and Deployment Support. Kick-off meeting.

Computational EngineerTransportation Research and Analysis Computing CenterEnergy Systems DivisionArgonne National LaboratoryOctober 27, 2011

Dr. Hubert Ley, Dr. Vadim Sokolov, Dr. Joshua AuldDr. Kuilin Zhang, Mr. Michael Hope

Reporting

Monthly highlights (1-2) pages. To be available @wiki.anl.gov/megapolis Monthly meetings with Brian Gardner. Monthly notes to be prepared prior to

meetings @ http://anl.adobe.com/transims Quarterly reports Publications in journals, Conference presentations

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Resources

Is carry over allowed? Hire a postdoc, preferably CS grad, with machine learning or AI background, with

experience in working on a large scale software development project Recommendations from Brian on a candidate

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Task Overview

Task 1: Administration Task 2: Transport Simulation Interoperability Research Task 3: Command, Control, Communication, and Information Model Prototype Task 4: Deployment Support Task 5: Computing Support

Motivation for a New TRANSIMS Component Proper delivery of Tasks 2 and 3 will be predicated on development of a

prototype with the following characteristics:– Accessible to the transportation community– Ability to be calibrated and validated– High performance– Extensibility to entirely new applications– High degree of modularity / flexibility

A model able to satisfy Tasks 2 and 3 must have the following capabilities:– An architecture which allows the agent to be informed actively by transportation

elements traditionally outside the scope of an activity based model such as: prevailing congestion or dynamic network state

– An architecture which allows the 3CI systems to cause behavioral adjustments across numerous traveler actions such as: driving tactics, route choice, and activity choice

Motivation for a New TRANSIMS Component cont’d

Possible ways to satisfy the requirements of Task 2 and 3:– Loosely couple existing activity choice, routing, 3CI, and simulation

codes through extensive source code modification and message or file passing

– Heavily upgrade the TRANSIMS 5.0 Simulator to flesh out route choice and add activity choice / 3CI support

– Start fresh and develop a tool which fits into the TRANSIMS toolbox, but which exactly satisfies the delivery requirements

It is the current assertion of the TRACC team that the final option holds the best potential to both satisfy the requirements of the contract as well as provide the basis for a novel new framework for transportation planning models

Megapolis Overview

“Megapolis” is the codename for the new TRANSIMS tool to be developed

Megapolis is a single integrated utility which will handle the following TRANSIMS tasks in a single execution run:

– Activity Generation and Scheduling– Activity Planning including Destination, and Mode Choice– Time Dependent Route Choice– Low Resolution Simulation: Queuing Model– High Resolution Simulation: Car Following, Lane Changing, and En-Route Path

Choice

Additionally, Megapolis will handle the following tasks specific to this project:

– Activity and route choice informed by prevailing network state and congestion as well as predicted future network state and congestion

– Modeling of 3CI systems able to affect a large variety of potential agent actions, flexible custom implementation

Integration With TRANSIMS

TRANSIMS Network

Generation

TRANSIMS Network

GenerationMegapolis

TRANSIMS VisualizerTRANSIMS Visualizer

TRANSIMS Output Files

TRANSIMS Output Files

TRANSIMS RouterTRANSIMS Router

TRANSIMS SimulatorTRANSIMS Simulator

TRANSIMS Activity Generation

TRANSIMS Activity Generation

TRANSIMS ArcToolsTRANSIMS ArcTools

TRANSIMS Studio

or

Static Modeling Dynamic Modeling Results Inspection

Tool Integration

TRANSIMS Signal

Generation

TRANSIMS Signal

Generation

TRANSIMS Transit

Network Generation

TRANSIMS Transit

Network Generation

Major Megapolis ComponentsFoundational

Task Scheduler– Acts as a “job submission” system for various tasks within the software in order to

parallelize and load balance the work

Data Containers Library– Specialized data containers to optimize certain aspects of data use such as

memory usage, element access speed, or thread safety– API to data structures rooted in STL API, most will be a wrapper around STL

structures

Discrete Choice Model Sub-Processor– Highly optimized engine to evaluate many classes of discrete choice models – the

basis of agent choice in many of the other modules (regression models, nested-logit, first order logic, Bayes network, neural networks)

Major Megapolis ComponentsModeling

Activity-Based Demand Model– Activity Generation Model– Activity Planning Model– Destination, Mode, Party Composition and Timing Choice Model– Activity Scheduling

Path Choice– Route Choice Model – A* + Lookup tables for paths between “hubs”– En Route Choice Model – D* / D*Lite

Driver Simulation– Strategic Lane Choice Model – Lane Utility Model– Discretionary Lane Choice Model – Intelligent Driver Model– Car Following Model - Intelligent Driver Model– Intersection passing model

Activity-based Demand Model

Combine concepts from ADAPTS, OpenAMOS, and

others

ADAPTS/AMOS – planning of activities concurrent

with travel simulation

ADAPTS adds:

– planning ahead (future timesteps)

– Flexible planning order of activities/attributes

– Modeled activity fixity/flexibility

Replace AMOS activity-travel simulator

OpenAMOS

ADAPTS

Major Megapolis ComponentsIntegration

IO Library– Library which handles file structures, reading, writing, and serialization for restart

Batch Iteration Model for Cluster Operation– Tool to design and execute a sequence of Megapolis runs to establish an

equilibrium in results

Visual Interface / Model Feedback Mechanism– Use of TransimsVIS and existing TRANSIMS utilities for initial feedback– Graduated development of additional visual module used for interactive

feedback during model execution

Bug Tracking and Roadmap

https://trac.anl.gov/megapolis/ - An open source, web-based project management and bug-tracking tool will be used for this project

– Argonne SVN to be used for version control– Trac is integrated with svn– svn.anl.gov/megapolis/– Available from outside of ANL domain– Accessible for ac.bgardner– Roadmap at trac.anl.gov/megapolis/roadmap

https://wiki.anl.gov/megapolis/ - An Argonne MediaWiki page used by the team for internal communication, project layout, and reporting– Supports file and media upload / display– Uses simple wiki language and linked page structure– Accessible for ac.bgardner

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