Travel Demand Forecast Model Project

Introduction

The Community Development, Public Works, and Transportation Departments worked together on the Travel Demand Forecast Model project from 2018 to 2020. The primary purpose of the project was to build a model, design a vehicle miles traveled (VMT) tool, update the City’s Transportation Study Criteria and Guidelines, and establish a mobility fee program for the City to comply with Senate Bill 743 and inform the City’s General Plan Update project. A summary of all regulations tools, and fees resulting from the project include:

  • Updated level of service (LOS) requirements
  • Updated non-LOS/VMT requirements
  • Updated transportation study review fee 
  • New VMT screening, impact thresholds, and mitigation options
  • New travel demand forecast model
  • New project-level calculator tool
  • New VMT impact (mobility) fee

As of March 2021, all of these are completed except the mobility fee program is anticipated for adoption in the upcoming Fiscal Year 2021/2022 budget cycle. Developers looking for the tool, tool user guide, and the Transportation Study Criteria and Guidelines can access them on the City’s Transportation Study Information webpage. Feedback forms are also available on that page so users can let the City know how the tools could be improved.

The following provides additional project and background information.

Senate Bill 743

In 2013, the State of California passed Senate Bill 743 (SB 743), which alters how agencies measure transportation impacts under the California Environmental Quality Act (CEQA).

CEQA requires review and disclosure of environmental impacts caused by projects that are not categorically exempt from review, and to avoid or mitigate those impacts if feasible. When passed, SB 743 directed the Governor's Office of Planning and Research (OPR) to develop guidelines for an alternate metric to level of service (LOS) to evaluate transportation environmental impacts under CEQA, consistent with SB 743's intent.

The intent for cities, as lead agencies under CEQA, is to establish thresholds, develop mitigations, and evaluate transportation impacts with metrics that support the reduction of greenhouse gas (GHG) emissions, development of multimodal transportation networks, and diversification of land uses to promote statewide goals of public health, infill, and GHG reduction.

Starting July 1, 2020, all lead agencies must use VMT, and cannot use LOS, to analyze transportation impacts under CEQA, to comply with SB 743. While LOS was the default metric for determining transportation environmental impacts for many years, it is a vehicle operation focused measure that does not support statewide sustainability goals and can no longer be used to comply with CEQA. Cities can still use LOS for their local development review process to inform site access and traffic operations, outside of the environmental review process.

Travel Demand Forecast Model

A travel demand forecast model is a computer program that simulates the amount of traffic levels and travel patterns for current and future conditions. This model helps the City understand how citywide programs and plans, land use changes, and development projects impact the way we move through the city. The model can:

  • Measure how potential changes in land use impact travel in and through Culver City
  • Help the City design efficient ways for pedestrians, bicyclists, scooter users, transit riders, and drivers to get around
  • Clarify how changes in the city help or hinder efforts to address climate change and greenhouse gas emissions
  • Assess how well strategies meant to decrease demand for car travel are working
  • Measure how changes to the urban fabric influence how people choose to get around
  • Provide data on vehicle usage to meet the requirements of the California Environmental Quality Act for larger, citywide land use and transportation projects

The model was prepared in time to inform the preparation and impact analysis of the City’s General Plan Update. Once the updated General Plan is adopted the model will require updating with the newly adopted land use plan. The General Plan is expected to be adopted in the last quarter of 2022.

The model is not intended for use by applicants for development projects as it has limited capacity to provide accurate results at a project level. That is where the VMT tool takes over.

Vehicle Miles Traveled (VMT) Tool and User Guide

The VMT tool allows for analysis of transportation environmental impacts of development projects in Culver City. It incorporates VMT screening criteria, impact analysis, and mitigations - providing a consistent data-based method for transportation impact analysis for all development projects. It estimates project-generated VMT per capita and employee, which is compared to the impact thresholds to make an impact determination.

A project's VMT is calculated by combining project trip generation and length. When generating trips, the tool accounts for the benefits of transit proximity, mixed land uses, and urban design. Validated assumptions from Fehr & Peers' Mixed-Use Development Trip Generation model are used, along with data from the travel demand model.

In addition to providing project VMT and figuring out project impacts, the tool provides a method for mitigating impacts through Transportation Demand Management (TDM) measures. It quantifies the effectiveness of the mitigation measures based on available data. In summary, the tool allows users to:

  • Determine if their project is screened out from having to analyze VMT impacts
  • If their project is not screened out, whether it has less than significant impacts
  • Enter Transportation Demand Measures (TDMs) to understand how their project’s VMT impacts could lessen
  • Adjust project variables to determine how to modify a project so that it would have a less than significant impact

The VMT tool and user guide are on the City’s Transportation Study Information webpage.

Transportation Study Criteria and Guidelines

The City updated its old “Traffic Study Criteria for the Review of Proposed Development Projects within the City of Culver City” to comply with changes in state environmental and planning laws. The updated Transportation Study Criteria and Guidelines are on the City’s Transportation Study Information webpage.

This document guides developers on what is needed to analyze a project's transportation impacts. It includes an expanded CEQA section on how the VMT transportation impact analysis process should be conducted, based on VMT screening, impact thresholds, and mitigations. In addition to CEQA analysis, updated guidance is included on LOS operational analysis and non-VMT/LOS features.

VMT Impact Mobility Fee Program

This page will be updated with information on the mobility fee program upon City Council adoption. 

Resources 

Have Questions? Contact Ashley Hefner Hoang, AICP, Advance Planning Manager at ashley.hefner@culvercity.org

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