Transportation Demand Management (TDM)

Copy of TDM_Hero-Image_TDM-Website - 1

Transportation Demand Management (TDM) is the use of strategies to inform and encourage travelers to maximize the efficiency of our transportation systems leading to improved mobility, reduced congestion, limit single occupancy vehicle (SOV) trips, and lower vehicle emissions. TDM strategies have been shown to be a cost-effective means of meeting key policy objectives.  

TDM is particularly relevant to the state of Tennessee, according to the 2022 US Census, Tennessee has a higher percentage of work-related travel involving a SOV trip (75.0%) than the national average (68.7%) [1]. This high rate of SOV travel has significant impacts on Tennessee’s traffic congestion and travel time reliability, as well as the health of our communities. High levels of SOV travel exacerbate congestion, leading to longer travel times and reduced mobility for commuters. Additionally, SOV travel contributes to poor air quality, which can have an impact on the health of vulnerable populations. 

By strategically deploying TDM strategies, Tennessee can potentially reduce SOV trips and the vehicle miles traveled (VMT) on Tennessee roads. By reducing VMTs, Tennessee could extend the life of its roadway systems, spend less on road maintenance, reduce congestion, and allocate tax-payer dollars to other areas of interest and more importance. 

If you’re interested in estimating the benefits of a particular TD program, LDA Consulting’s TDM Return on Investment Calculator is a valuable tool to consider. This calculator helps users calculate vehicle trips and miles reduced by their TDM programs, and to calculate benefit-cost ratios or ROI. You can download the spreadsheet-analysis method and user manual by visiting Mobility Lab | TDM ROI

Additionally, the Center for Urban Transportation Research has developed the TRIMMS model 4.0 (Trip Reduction Impacts of Mobility Management Strategies), which has incorporated new background data on TDM strategies. TRIMMS assesses the impact of a broad range of TDM initiatives and provides cost-effectiveness analysis of programs such as net program benefits and benefit-to-cost ratio analysis at an area-wide or site-specific level. The model is based on default literature-based parameters for 99 metropolitan areas and constant-elasticity demand functions. You can download TRIMMS by visiting Mobility Lab | TRIMMS 4.0

[1]  U.S. Census Bureau. "Commuting Characteristics by Sex." American Community Survey, ACS 1-Year Estimates Subject Tables, Table S0801, 2022

TDM Plan Mobile - 1

 

Statewide Transportation Demand

Management Plan

In 2017, the Tennessee Department of Transportation’s Long Range Planning Division conducted a statewide TDM study that led to the production of the Statewide TDM Plan. The Plan outlines various TDM strategies that could be used to lower SOV trips while supporting economic growth across the state. TDOT is currently in the process of updating this Plan - which is expected to be complete by Fall 2025.  

 

Statewide TDM Programs, Partners & Stakeholders

TDM Program Viewer

The Tennessee Department of Transportation (TDOT) has developed an interactive map of Tennessee's array of TDM strategies being implemented across Tennessee. Explore the existing landscape with the ability to pinpoint areas of opportunity for development and optimization. Whether you're a planner, policymaker, or enthusiast, this map offers insights to enhance transportation efficiency, safety, and accessibility.  *Click the image to view the map.

TDM Plan Mobile - 2

Quarterly TDM Coordination / Collaboration

The quarterly TDM Coordination/Collaboration call is a forum convened by the Tennessee Department of Transportation’s (TDOT) Air Quality Office, bringing together transportation demand management (TDM) professionals from across Tennessee to share best practices, exchange industry knowledge, discuss current challenges and relevant events, and identify opportunities for collaboration. This call aims to build a stronger TDM community and support the ongoing development and implementation of effective TDM strategies and programs across the State.  

If you are interested in participating in these calls, please contact Savannah Robertson

TDM Plan Mobile - 3

In addition to resources provided by TDOT, there are numerous training opportunities from other TDM organizations. 

  1. Association for Commuter Transportation (ACT) offers a variety of training and educational resources on TDM practices, including webinars, online courses, and in-person training sessions. They also have a certification program for TDM professionals. Learn more Association for Commuter Transportation | ACT (actweb.org) 
  2. Transportation Research Board (TRB) provides research and educational resources on transportation-related topics, including TDM. They offer several training courses, workshops, and webinars on the most up-to-date practices and search. Learn more Transportation Research Board | National Academies 
  3. Federal Highway Administration (FHWA) offers several webinars, online courses, and technical assistance programs. Learn more Federal Highway Administration (dot.gov)
  4. Center for Urban Transportation Research (CUTR) provides trainings and technical assistance on transportation-related topics, including TDM. They offer several webinars, online courses, and training programs on TDM practices, research, and policy. Learn more CUTR – Center for Urban Transportation Research | University of South Florida (usf.edu)  
  5. Smart Growth America (SGA) is a national organization that promotes sustainable land use and provides technical assistance, advocacy materials, and thought leadership. They offer several training resources, including webinars, online courses, and technical assistance. Learn more Smart Growth America 
  6. National Association of City Transportation Officials (NACTO) is an association of 100 major North American cities and transit agencies formed to exchange transportation ideas, insights, and practices and cooperatively approach national transportation issues. Learn more National Association of City Transportation Officials (nacto.org)