About Trimms

the tool

TRIMMS is a visual basic (VB) application spreadsheet model that estimates the impacts of a broad range of transportation demand initiatives and provides program cost effectiveness assessment, such as net program benefit and benefit-to-cost ratio analysis.


TRIMMS evaluates strategies directly affecting the cost of travel, like public transportation subsidies, parking pricing, pay-as-you-go pricing, and other financial incentives.  Subsidies are provided to the employee by the employer to reduce the costs associated with the use of a particular method of commuting.  Subsidies can take different forms such as cash, discount passes, and vouchers.

How can I use Trimms?

TRIMMS also evaluates the impact of strategies affecting access and travel times and a host of employer-based program support strategies, such as: 

  • TDM program support initiatives
  • Alternative work schedules
  • Telework
  • Flexible work hours
  • Worksite amenities  
  • Rideshare matching services
  • Guaranteed ride home or emergency ride home for vanpool and carpool users
  • Vanpool formation support
  • Employee transportation coordinators
  • Compressed work week
  • Flexible working hours
  • Provision of childcare facilities 
  • Presence of sidewalks connecting transit stops within or nearby the worksite

Getting Started

To download TRIMMS:

1. Go to Download page

2. Unzip the files to your local drive

3. Follow the instructions to set up and use TRIMMS


Watch videos on how to use TRIMMS tool with examples:

Basic introduction to TRIMMS

Advanced use and examples


View a representative sample of how TRIMMS is being used or cited at federal, state and local levels.

Our developers

TRIMMS™ (Trip Reduction Impacts of Mobility Management Strategies) was developed by the National Center for Transit Research and the Center for Urban Transportation Research at the University of South Florida under a grant from the Florida Department of Transportation and the U.S. Department of Transportation.