TDMCalculator

A Tool to Quickly Test VMT Reduction Strategies

Communities are working to reduce vehicle miles traveled (VMT) as they balance growth, climate goals, and quality of life. Transportation Demand Management (TDM) strategies, like improved transit access, parking programs, or incentives for carpooling and biking, can help. But understanding which strategies will have the greatest impact in a specific location is not always straightforward.

The Excel-based TDMCalculator makes that process faster and easier. It draws from the widely used transportation strategies we helped author in the 2021 CAPCOA Handbook for Analyzing Greenhouse Gas Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity (CAPCOA Handbook).

Woman uses bike share and rides along a path as buses and pedestrians pass by in the background
The new San Diego blue line trolley station platform at UCSD Medical Center on Nobel Drive.

The TDMCalculator tool allows planners, agencies, and developers to quickly combine and compare strategies and estimate potential VMT reduction.

View the Tool

GHG and VMT Reduction

Because the methods align with CalEEMod, California’s standard model for detailed GHG emissions analysis, the results can also support GHG reduction analysis for climate action planning. The following shows the percentage of VMT or GHG that would be mitigated using each strategy.
  • Transit Oriented Development 31% 31%
  • Increase Residential Density 30% 30%
  • Increase Job Density 30% 30%
  • On-Street Market Price Parking 30% 30%
  • Improve Street Connectivity 30% 30%
  • Affordable and Below Market Housing 28.6% 28.6%
  • Trip Reduction Program (Mandatory) 26% 26%
  • Employer Sponsored Vanpool 20.4% 20.4%
  • Price Workplace Parking 20% 20%
  • Unbundle Residential Parking & Property Cost 15.7% 15.7%
View the full List

Designed for Real-World Planning

Unlike many VMT calculators that rely on rigid assumptions or complex custom modeling software, VMTCalculator is built for quick testing, transparency, and practical use in planning workflows.

Quick to Deploy

Runs in Microsoft Excel. No specialized software required.

Customizable Defaults

Offers preloaded values from statewide and national travel survey data. We can also update the tool with local inputs and tailored strategies to fit each agency’s needs. See a customized example through Caltrans.

Built-In Guidance

Flags conflicting strategies and links directly to supporting calculations.

Targeted Insights

Breaks out reductions for commutes, households, and project-related trips to see which strategies matter most to your goals. Includes simple guidance for converting weekday results into annual estimates.

Geographic Context

Maps counties within each Core Statistical Area (CSA) or region in California to show how regional defaults apply, especially for rural areas where other tools lack guidance. The tool draws on national travel data, allowing the approach and findings to be adapted in other regions.
Pedestrians walk across the street as a car passes through intersection behind them

When to Use TDMCalculator

TDMCalculator is designed for early-stage analysis where quick, clear comparisons are critical, including:

Project Scoping

Testing strategies before committing to larger models.

Policy Evaluation

Comparing options in general plans, specific plans, or climate action plans.

Developer Coordination

Demonstrating VMT reduction commitments during permitting and approvals.

About the Data

The TDMCalculator is grounded in the CAPCOA Handbook and its published formulas for quantifying TDM measures. These reduction factors were developed using state and federal data and supported by published research.

The Handbook itself was created through a collaborative process involving experts from public agencies, universities, and community organizations, with peer review at every stage. As authors of the Handbook’s transportation strategies, we bring direct insight into how these methods can be applied, combined, and adapted to reflect real-world project conditions.

Together, these sources reflect the most reliable, research-based understanding of how TDM strategies perform in communities.

CAPCOA HANDBOOK
MORE ON CALEEMOD
MORE ON VMTIMPACTS
MORE ON TDM

Let’s Connect

Have questions? We’re here to help.

Kellie Dugdale

Senior Transportation Planner

Email Me

TDMCalculator is a Fehr & Peers Research & Development project. Data and methods based on CAPCOA Handbook.