Data Requests

Each year, COG staff receive many requests for technical data sets and associated documentation not found on the COG website. Staff also provides some limited support to users of the TPB regional travel demand model. Technical staff have limited time and resources to respond to external requests for technical data, documentation, and travel model support. Nonetheless, we strive to strike a balance between performing core work activities and responding to data requests and/or model support questions.

Below are the current policies regarding responding to data requests and what we ask of you (the requestor). After reading and acknowledging these conditions, you may complete the data request form below.

Policies regarding data requests

1. To request a copy of the TPB regional travel demand model, model-related data sets, and/or documentation not found on the COG website, please use the form below. Your information will be sent to Mark Moran, Program Director, Travel Forecasting and Emissions Analysis, who will review your request and determine the timeline and best person to respond to your request.
2. We reserve the right to charge for staff time and materials required to fulfill data requests.
3. If you are requesting data or documentation that is “off the shelf” and limited in scope, then the request will likely be fulfilled in a few days, depending on staff availability, and at no cost to the requestor. Keep in mind that COG staff will need to 1) determine the best person to respond to the request; 2) find the data or documentation; and 3) prepare the data or documentation for transmittal.
4. If you are requesting data or documentation that requires substantial time to find, process, format, or prepare, COG staff will need to determine 1) if there are current staff resources available to fulfill the request; 2) if so, what level of effort is required; and 3) what funding source is to be used to cover staff time and/or materials needed to fulfill the request. COG staff does not have an established mechanism for receiving external funds to cover fulfilling data requests. In some cases, existing technical assistance funds can be used, but this requires special approval from the relevant funding entity, typically a state department of transportation (DOT) or a transit agency. In cases where we cannot identify a funding source, we will generally be unable to fulfill the request.
5. Requests for the TPB regional travel demand forecasting model
   1. Although we provide the travel model and its input files for free, running the travel model requires the use of a proprietary software package that is produced, licensed, and marketed by Bentley Systems, Inc. (e.g., Citilabs Cube Voyager, Cube Base). COG staff cannot provide this software.
   2. We do not have the resources to staff a "help desk" for the regional travel model, so it is expected that requesters of the travel model will have the knowledge and skills to use the model with minimal assistance from the staff.
   3. It is the staff policy to transmit only production-use travel models and adopted land activity forecasts. Thus, it is against staff policy to transmit developmental travel models or land activity forecasts since these have generally not been thoroughly vetted by staff and are not considered finished products.
   4. Production-use TPB travel demand forecasting model(s): There are currently two production-use models available, discussed below. We have prepared one model transmittal package for each model. Each model transmittal package consists of model scripting files, model input files, and related documentation. It does not include model output files due to their large size (10 to 25 GB per alternative/year).
      1. COG/TPB Gen2/Ver. 2.4.6 Travel Model: This model has not yet been used in an Air Quality Conformity (AQC) analysis, which means that it has not been implicitly adopted by the TPB (the TPB does not explicitly adopt a travel model; it adopts a study that makes use of a travel model, thus implying an implicit adoption of the model). However, this model has undergone a thorough review by the TPB staff and has deemed to be production ready. Consequently, this is the model that TPB staff plan to use in the upcoming AQC analysis, i.e., the AQC analysis of the Visualize 2050, which the TPB will review, and possibly adopt, in June 2025. The Ver. 2.4.6 Model transmittal package includes the same network years as the Ver. 2.4 Model (2017, 2021, 2023, 2025, 2030, 2040, and 2045). The land use included in the transmittal package is Round 9.2 (the same as is used for Gen2/Ver. 2.4 Model). Note that the upcoming AQC analysis, the Visualize 2050, will make use of Round 10 and the Ver. 2.4.6 Model. Once that AQC analysis has been adopted by the TPB, TPB staff will develop a new model transmittal package for the Ver. 2.4.6 Model specific to that analysis. Compared to the Ver. 2.4 Model, the Ver. 2.4.6 Model has the following updates:
         • Migration of the Transit Walkshed Process from ArcPy to GeoPandas.
         • Migration of the mode choice process from AEMS to TRANSIMS ModeChoice.
         • Updated the local bus speed/runtime degradation process. The updated process looks up the bus factors for both the current CPI year and modeled year (relative to 2015) and calculates the new bus degradation factors based on the original factors for both years.
         • Developed a process that would ensure that no row in the transit line files exceeds 144 columns.
         • Cleaned up the transit skimming/assignment report files.
         • Added an optional function to shut down the computer automatically after completing a model run, which can be useful when running the model on an on-demand cloud server, where cost is incurred based on time used.

For more details, see the Ver. 2.4.6 Travel Model user’s guide and the transmittal package memo for the Gen2/Ver.2.4.6 Model.

2. Gen2/Ver. 2.4 Travel Model: This model became the TPB’s adopted, production-use regional travel demand model for the metropolitan Washington region in June 2022 since it was used for AQC analysis of the 2022 update of the Long-Range Transportation Plan (LRTP), known as Visualize 2045. However, this model lacks several updates that staff have incorporated into the Gen2/Ver. 2.4.6 Travel Model. The air quality conformity analysis included the following network years: 2021, 2023, 2025, 2030, 2040, and 2045. Additionally, though not part of the AQC analysis, highway and transit networks associated with the year 2017 are also included in the travel model transmittal package to provide base-year networks that are consistent with the forecast-years networks. The land use forecasts provided in the model transmittal package are Round 9.2 Cooperative Forecasts.

For more details, see the Ver. 2.4 Travel Model user’s guide and the  transmittal package memo for the Gen2/Ver.2.4 Model.

6. If you would like to obtain zonal land activity forecast data, please let us know whether it is for use with the regional travel model or some other use, since that will determine the type of land use file you are sent. Zonal land use data for the regional travel model must undergo an adjustment to ensure that a consistent employment definition is used by all counties and jurisdictions in the modeled area.

What we ask of you

1. If your study results in a report or other similar documentation, we would like to get a courtesy copy of this document, so that we can better understand how our model/data has been used.
2. If you find anomalies or errors in the data or model, please let us know about them, so that we can address them as quickly as possible.