WFRC employs sophisticated transportation and land use modeling tools to provide decision-makers, agency staff, and the public with reliable, insightful forecasts from which to analyze future scenarios and best inform planning for our Region.
As transportation and land use are mutually dependent, forecasting for both of these systems must work in tandem in order to optimally support the development, selection, and prioritization of future transportation projects to meet future needs. Similarly, the integrated modeling tools are critical for exploring local land use policies such as those that promote urban and local centers, and the impact of our urban systems on air quality.
Projected measures produced with assistance from transportation and use models include:
- future population, household, and employment distributions;
- travel patterns and mode share;
- future vehicle and transit volumes and their relationship to the capacity of existing facilities and services;
- travel times and comparative accessibility to workplaces and other key destinations; and
- key inputs to air quality mobile-source emission models
Developing and maintaining travel and land use models is a best practice for regional planning. But it also fulfills requirements and expectations needed to continue to receive our Region’s share of federal transportation funding. Accordingly, WFRC’s modeling processes comply with federal law (FAST Act, MAP21, and Clean Air Acts) as well as guidance provided by the US Department of Transportation (USDOT), the Federal Highway Administration (FHWA), the Federal Transit Administration (FTA), and the Environmental Protection Agency (EPA).
The Wasatch Front travel and land use models are updated in sync with the four-year RTP cycle. These models serve the Salt Lake City-West Valley City, Ogden-Layton, and Provo-Orem Urbanized Areas. For more information, contact the WFRC Analytics Group.
Wasatch Front Travel Demand Model (v8.3.1)
Since 2000, WFRC has partnered with our neighboring MPO, Mountainland Association of Governments (MAG) to develop and support a shared, regionwide travel demand model.
Version 8.3 of the Wasatch Front Travel Demand Model (TDM) was used to support forecasting and scenario evaluation during the development of the 2019-2050 Regional Transportation Plan (RTP) and is the version released (August 22, 2019) for official use coinciding with the formal adoption of the 2019-2050 RTP document.
Version 8.3.1 of the Wasatch Front TDM was officially released to the modeling community May 8, 2020 and includes model enhancements and project additions and modifications expected to be made to the WFRC and MAG 2019 RTPs. The following resources are now available for the the 8.3.1 model release:
- This What’s New document describes enhancements and changes within the 8.3.1 TDM release
- Model Inputs documentation for 8.3.x versions of the TDM
Annual Average Daily Traffic (AADT) – Historic & Forecast web map (includes analysis segment geometry and seasonal and other adjustment factors) — for the WFRC metropolitan planning area
- AADT datasets, the data elements displayed in the above web map are available in GIS, spreadsheet, or web service formats from WFRC’s open data site.
The TDM is a modified 4-step travel model that incorporates a travel time feedback loop in order to evaluate roadway congestion costs in its distribution of trip origins and destinations and its travel mode choice modules. The model calculates roadway volumes, travel speed indicators, transit route boardings, and regional statistics including vehicle miles traveled (VMT), vehicle hours traveled (VHT), transit/auto/non-motorized mode shares, and trip length costs.
The travel model includes the phased, fiscally-constrained 2019-2050 RTP roadway and transit projects and the official traffic analysis zone (TAZ)-level socioeconomic forecasts for the Region. WFRC and MAG have calibrated the model’s parameters to reflect local travel behavior patterns reported in the Utah Travel Study household survey (trip rates, trip lengths, time of day of trip, mode of travel, etc.) and validated the model’s results with observed travel conditions (transit ridership, roadway volumes, and roadway speeds) for the model’s base year, 2015. Additional processes, including external review, are used to validate the reasonableness of future year travel projections.
To request a copy of the current TDM, please contact Suzie Swim.
Real Estate Market Model (v1.0)
The current shared WFRC/MAG Real Estate Market Model (REMM) version is 1.0. The WFRC/MAG REMM relies on best available resources to project future residential and employment-related development activity using the UrbanSim modeling platform. In order to accurately model future years, REMM is first calibrated to best reflect the base year of the adopted RTP, currently 2015. Critical inputs to REMM’s consideration of available land and profitability of new and redevelopment activity include:
- A region-wide parcel land use and valuation database;
- An inventory of local government general plans;
- The results of a multi-year scenario-based visioning exercise;
- A synthesized household population dataset for the model’s base year (2015) based on Census data;
- Address geocoded employment totals from the Utah Department of Workforce Services (DWS);
- County-level employment and population control total projections, sourced from the University of Utah’s Kem C. Gardner Policy Institute;
- Public and private sector expert advisors; and
- ‘Physical constraint’ map layers that depict areas where future development is prohibited or not practical due to steep terrain, wetlands, mining, or public lands (formal designations or ownership).
REMM produces TAZ-level socioeconomic projections that are reviewed by staff and external experts for plausibility. The socioeconomic projections are packaged with the TDM files but are also available as GIS layers that can be viewed, downloaded (.shp, .gdb, .kml, or .csv), or used as web services from the data.wfrc.org open data website.
These household and job distribution projections inform future trip generation in the regional TDM. And in turn, REMM factors travel accessibility derived from the travel model into its predictions of land development activity.
WFRC and MAG hosted a expert peer review of REMM and its related processes in August 2019. Three land use modelers from comparable MPOs (Albuquerque, Detroit, Phoenix) were provided with REMM 1.0 documentation in advance of a 2 day in-person review seminar that featured presentations from and discussion among the panelists and WFRC/MAG area stakeholder agencies. The review concluded that REMM is well within best practices for land use modeling and recommended potential future areas of enhancement (view 2019 REMM Peer Review report).
Utah Bike Demand Model (v1.0)
WFRC, MAG, DOT, and UTA jointly funded the development of the Utah Bike Model (UBDM) with the model design and development work taking place in 2019 and 2020. The model currently covers the Wasatch Front urbanized area.
The v1.0 UBDM is a trip-based model designed to estimate bike trip production and attraction using a region-wide GIS layer of multi-use pathways and on-street facilities, together with block-size microzones that characterize resident demographics and the attractiveness of destinations to various types of bike trips.
The UBDM currently models 9 trip purposes: work, college, k-12 school, maintenance/utility, discretionary, recreation-family, recreation-under 5 miles, recreation-long distance, and recreation-mountain bike trailhead approach (dirt trail travel is not modeled). Network considerations include: level of bike facility, traffic stress, signalization, and elevation gain.
The parameters that determine bike activity within the UBDM were chosen and estimated using comparable information from the Sacramento metropolitan area, including that area’s 2018 mobile-device-based household travel survey. While the UBDM has not yet been calibrated to local bicycle travel behavior within our region, that effort is planned after the completion of the Utah statewide household travel survey in 2022/23 and the expansion of the regional bike counter program.
- UBDM design document
- List of UBDM inputs (for network links and microzones)
- UBDM project/code repository — model engine (trip generation and assignment, RSG managed repository)
- UBDM project/code repository — tools and configuration files (WFRC managed repository)
- UBDM informational slides (last updated 2020.10.06)