VisionEval responds to Bike Network Changes
A 2020 OregonDOT-Metro-NITC research project being led by Joe Broach of Portland State University, will update VisionEval code (VE-RSPM) to enable VisionEval to respond to bike networks as perceived by differnt users. This includes the following elements.
In the current VE-RSPM light vehicle (e.g. bicycle, electric bicycle, scooter) diversion module users specify the proportion of single-occupant vehicle (SOV) mileage diverted to light-vehicle travel in the base and future years. Historical value can be derived from household travel surveys bike usage; future year inputs are specified through aspirational goals or exploratory processes. Methods for generating realistic bicycle diversion input have not been established, and the inputs are hard to tie to specific investment actions. The exploratory or aspirational approaches can be useful for strategic planning purposes, providing decision makers with information about what levels of SOV diversion to bicycle travel are necessary to meet identified goals, but they do not offer information about the level of infrastructure or other transportation system investments needed to achieve the given levels of bicycle diversion.
The objective of the proposed research is to develop a new bicycle diversion module for the GreenSTEP-derived family of scenario planning models that internalizes bicycle diversion within the model by allowing users to specify changes in cycling infrastructure (and allow the model to estimate diversion), rather than assuming the outcome of cycling investments.
The research will develop new VE-RSPM modules to estimate SOV short-trip diversion, using input variables related to:
- Socio-demographic and other household characteristics (drawing from existing variables in the model),
- Land use characteristics (again drawing from existing variables in the model), and
- Bicycle network characteristics.
Because VisionEval does not use an explicit network, bicycle network indicators will be used to represent the attractiveness of the bicycle facilities near the home location. The anticipated work includes pre-processors to extract bicycle network indicators from detailed bike network data, and potentially terrain data (from a digital elevation model) to capture the effects of hills on cycling propensity. Bicycle network indicators that may be included in VisionEval include the coverage, connectivity, and quality of bicycle facilities, and other measures shown in past research to have a significant relationship with cycling volumes, cycling mode share, or cycling attractiveness.
Several pre-processors are under consideration to develop connectivity and quality of bike networks, including: Bike Level of Traffic Stress (LTS)(see ODOT APMv2_Ch14), Highway Capacity Manual Multi-Modal LOS methods (see TRB), and Scalable-Risk Analysis Method (SCRAM).
The following figures highlight the selected changes that the model makes to the VE-RSPM packages and modules.
Note: The project also intends to synchronize the disaggregate Bike Network assumptions with the Bike Module in Portland Metro's new Activity Based Model, where the full network, not just the aggregated metrics of VisionEval, could be utilized directly.
The VisionEval Bike upgrades will change both methods, inputs and outputs. Methods will reflect the new functional form of travel by mode, and new data (updated NHTS2009 and EPA SLD land use data), leading to different outcomes for household travel by bike.
Users will likely need to provide more detailed bike network data (for historic and forecast years) to a pre-processor to develop Bzone inputs for use in VisionEval.
The multi-agency research agreement was signed in early 2020. The Research team anticipates the project will last roughly 12-18 months. As with other VE research, additional efforts may be needed to implement the work within the VE codebase.
The following people are involved in the Research.
Research Team:
- Joe Broach, Portland State University
- Josh Roll, ODOT Research
- Kristi Currans, University of Arizona
- Jaime Orrego-Oñate, Portland State University
- Alex Bigazzi
Technical Advisory Committee:**FIx LIST
- Brian Gregor, OSA
- Tara Weidner, ODOT
- Liming Wang, PSU
- Jeremy Raw, FHWA
More information about the research may be found at: https://nitc.trec.pdx.edu/research/project/1314/Incorporating_Bicycle_Activity_and_Vehicle_Travel_Reduction_from_Bicycle_Infrastructure_into_Strategic_Planning_Tools
Contact: Joe Broach, PSU If you are interested in implementing the model in your region, please contact Josh Roll or Tara Weidner at OregonDOT.