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BEAM v1.0.0

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@zneedell zneedell released this 31 Oct 22:30
· 2 commits to develop since this release
v1.0.0
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Summary

This release introduces substantial improvements and new capabilities to BEAM, incorporating changes made since the SMART 1.0 runs at the end of 2019. Key updates include enhanced integration with other tools, expanded functionality in freight simulation, a reworked mode-choice structure, and new emissions calculation capabilities. Below are detailed descriptions of the major enhancements in this release:

Major enhancements

1. Enhanced Integration with PILATES and ActivitySim

  • Merging and Iteration Selection: BEAM can now merge and select input and output plans from previous BEAM and ActivitySim iterations, streamlining multi-stage simulation processes in PILATES.
  • Skim Generation: BEAM generates skims in .omx format for ActivitySim, supporting seamless interchange of travel data and enabling iterative simulations to better reflect real-world conditions.
  • Expanded Vehicle File Support: Vehicle files from ATLAS can now be imported directly into BEAM, offering more flexibility for handling various data formats.

2. Freight Simulation

  • Dedicated Freight Vehicle Simulation: Freight vehicles, complete with input delivery plans, can now be simulated in BEAM, allowing a more comprehensive analysis of both passenger and commercial transportation systems.
  • Routing Restrictions: Freight vehicles can follow designated routes, with routing restrictions in place for heavy-duty vehicles.
  • Dynamic Tour Regeneration: Freight tours can be dynamically updated based on current travel times, improving responsiveness to changing traffic conditions and optimizing delivery efficiency.

3. Improved Tour Mode Choice Mechanism

  • Expanded Mode Choice for Complex Tours: Originally designed for simple round-trip tours (e.g., home -> work -> home), BEAM now supports complex multi-stop tours generated by activity-based models like ActivitySim.
  • Two-Stage Mode Choice Process: BEAM has introduced a two-stage mode choice process, where a tour’s primary mode is chosen initially, followed by individual mode selection for each trip within the tour.

4. Parking Management Enhancements

  • Link-Level Parking Assignments: Parking stalls are now associated with specific links on the road network, rather than broader zones, for greater granularity. Input shapefiles map links to TAZs, and the model calculates parking stall availability based on these individual links.
  • Accurate Skim Generation with Link-Level Mapping: Trip origins and destinations are matched to TAZs via link mapping, enhancing the accuracy of skims generated and allowing for more precise simulation outputs.

5. Activity Generation and Skim Improvements

  • Generation of Non-Mandatory Activities: BEAM can now generate non-mandatory tours and sub-tours, using skims to inform destination choice models. Parameters are derived from the NHTS, improving model alignment with real-world travel behaviors.
  • Improved Skim Accuracy: By refining TAZ-to-link mappings and skim generation protocols, the model produces more accurate travel time estimates, supporting more reliable outputs in activity-based modeling contexts.

6. Advanced Emissions Calculations

  • Air Pollution and GHG Emissions: BEAM now has the capability to assign emissions rates to vehicular activities through its new emissions module. This enhancement allows for a more realistic accounting of all emissions processes and pollutants modeled by CARB’s EMissions FACtors (EMFAC), or any other emissions rate-based model or data, which are produced by either passenger or freight operations, including cold start and idling emissions. BEAM-emissions collects these observations hourly and records them as skims by link, vehicle type, and process.
  • Python script pipeline for emissions: In addition to integration, BEAM now includes a new pipeline composed of various Python scripts for preprocessing EMFAC data and freight plans, mapping vehicle types to align the freight fleet with the emissions rate model fleet, and post-processing BEAM-emissions skims.

Additional Improvements

  • Performance and Stability: The release includes a variety of performance optimizations, bug fixes, and logging enhancements, ensuring that BEAM runs more efficiently in high-demand simulation environments.
  • Expanded Documentation and Getting Started Guide: The documentation has been updated, with a new developer guide available to assist contributors and users.

Major PRs included:

Integration

  • Support for merging and selection of previous BEAM and ActivitySim iterations (PR #3337)
  • Skim generation compatible with ActivitySim (PR #3238)

Freight

  • Freight vehicle simulation with defined delivery plans (PR #3168)
  • Enhanced routing for heavy-duty vehicles (PR #3514)

Mode Choice

  • Refactored mode choice process for complex, nested tours (PR #3900)

Parking

  • Link-level parking stall assignment (PR #3319, PR #3064)
  • Improved TAZ-based parking availability calculations (PR #2911)

Activity Generation

  • Non-mandatory tour and sub-tour generation (PR #2342)

Emissions

  • Detailed particulate matter (PM) and CO2 emissions calculations (PR #3885)

Planned features for v1.1.0

– Improvements to ridehail->transit mode routing: PR #3818
– Faster skims generation: PR #3899
– Improved detail in reading input plans (tolled vs non-tolled routes, specific transit types, specific vehicle IDs)

What's Changed

Full Changelog: v0.7.0...v1.0.0

Contributors

colinsheppard, michaz, and 18 other contributors
Assets 2
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