Strategies for Multimodal Mobility
September 17, 2025
08:30 AM – 10:00 AM at Ski-U-Mah
Ray Saeidi
Rick CurryOrange County Transportation Authority (OCTA) is prioritizing active transportation (AT) in their plans. Over four hundred miles of regional bikeway corridors have been recommended through a countywide effort involving local jurisdictions and stakeholders, further expanding a network of more than 1,000 miles of bikeways. Systematic evaluation and cost-benefit analysis of new bike infrastructure is limited by lack of bike infrastructure sensitivity in the OCTA travel demand model (OCTAM). A straightforward, low-cost, first phase improvement to OCTAM was developed to add this sensitivity. The improvements made to OCTAM incorporated three factors important to bicycle riders: comfort, safety, and exertion level. The implementation path included updating the OCTAM network with bike-related geospatial data, reflecting these factors in the OCTAM distance skimming procedures, and incorporating a simple bike assignment routing method. The three factors were addressed using the following network elements: 1) bike infrastructure classes added to the network identify the level of comfort a rider feels based on their separation from other roadway uses; 2) a measure of the amount of traffic the roadway might carry addresses the level of biking safety; and 3) roadway slopes, in particular directional uphill segments, factor in the level of biking exertion. Data being used are readily available from OCTA such as their GIS bike facility map and their internal processing of elevations from ESRI digital elevation models. The sources used are not limiting factors for other agencies as other open-source data are available. The bike skimming procedures use link-level weights, based on the literature, to produce new origin-destination weighted distances and times for mode choice. The weights measure the perceived value, in terms of bike time, of safety, comfort and exertion where, for example, for every minute spent on a 10% slope a bike rider would go four minutes out of their way to avoid the slope. The same link-level weights were used during assignment to route bike trips on a minimum weighted distance path. Route assignment was evaluated using collected bicycle counts throughout Orange County. With this initial phase improvement, OCTA will be able to use their travel model during evaluation and prioritization of bikeway facilities, future analysis of regional bikeway plans, and can potentially assess e-bike adoption impacts. This improvement applies a direct, low effort implementation method for improving bike infrastructure sensitivity in a travel model system whether it be a 4-step or activity-based model. Contributors: Anup Kulkarni (OCTA), Brian Smolke (OCTA), Archie Tan (OCTA), Rick Curry (WSP), Dora Wu (WSP), Ashlyn Clarry (WSP), Alice Huang (WSP) |
Joe BroachGiven limited resources to close gaps in regional trail systems, which projects will return the biggest bang for an agency's buck? Metro (Portland, Oregon's MPO) recently applied their regional travel model to produce mode, destination, and route shift estimates to inform user, health, and emissions benefit estimates for a selection of potential trail gap closure proposals. The analysis leveraged Metro's detailed regional bicycle model, which includes calculation of maximum utility bike routes on a comprehensive streets and trails network; an in-house Active Transportation Return on Investment tool; and benefit estimation guidance from US DOT.
Along the way, Metro modeling staff developed new methods to distribute impacts across overlapping projects. Results were used to create project-level benefit calculations for use by sponsoring local agencies to pursue grants and other funding opportunities. Implementation revealed both strengths and limitations of Metro's current trip-based regional travel modeling capability.
Joe FloodAbstract Title: Modeling Emerging Mobility Using ActivitySim
Authors: Joe Flood, Will Alexander, David Hensle, Ali Etezady, Joel Freedman, Bhargava Sana, April DeJesus, Samaya Elder, Khalisa Bolling, Susan Freedman
Topic: Emerging Travel Behaviors
Background To Problem
New technology has identified emerging mobility options that have limited available data but significant impacts on travel behavior and meeting overall greenhouse gas reduction goals. The proliferation of smartphones led to the rise in emerging mobility like microtransit, micromobility and Transportation Network Companies like Uber and Lyft, and the ongoing climate crisis has incentivized an increase in the use of electric vehicles and other emerging mobility options that support mode shift. Planners need to account for these rapid technological changes, and thus regional transportation models need to have the capability to support decision making during this transitional phase and answer questions about these emerging mobility options, such as how many people use them, where they go, and how they will impact the region’s transportation system as a whole.
Description of Application
San Diego Association of Governments (SANDAG) recently implemented, calibrated, and validated an ActivitySim model as the model of record for its 2025 Regional Plan. The model was enhanced to address micromobility, microtransit, and vehicle type choices. These changes included policy dials to test scenarios that impact planned projects and prioritization of investments, such as how microtransit wait times would affect boardings or how much rebates for EV purchases would increase eVMT.
Model parameters for these new mobilities were estimated or calibrated with base-year data, though limited. For example, SANDAG planners hope to have 21 microtransit and 15 neighborhood electric vehicle (NEV) services operating by 2035, but only two were in operation during the 2022 base year. While the calibrated base-year boardings match observed data, extrapolation is necessary to estimate boardings for future-year services. Sensitivity tests demonstrate that increasing ebike ownership rates increased ebike trips, increasing the number of chargers and giving households rebates to purchase EVs increased EV ownership and eVMT, and decreasing microtransit wait times increased microtransit boardings, all of which were expected.
Statement on Why Abstract is Noteworthy
This work demonstrates ways that emerging mobilities can be modeled even with limited observed data. The flexibility of open-source tools such as ActivitySim can make it easier to adapt models to account for rapid changes in how people can travel.
Project is complete.
· Additional sensitivity tests may be conducted during Spring 2025