Decision Making Under Deep Uncertainty

Objective: Promote a broad understanding of practical approaches to effectively inform decision-makers faced with uncertainty underpinning baseline assumptions in travel forecasting and planning


AEP50 stakeholder comments highlighted the need and challenge to practically engage in uncertainty modeling. Resources and research are becoming increasingly available, but there is much work done to help bridge the gap between research and practice. At the core of this initiative is the question: how reasonable is it to produce a single best-guess 25 year forecast to inform the transportation planning practice? To stay useful (and relevant) to the public process, our tools and methods need to evolve.


The decision making under deep uncertainty (DMDU) approach developed in other industries presents a model for how travel forecasting and planning can shift from a “predict-then-act” approach that optimizes against a “best-guess” future to an approach that stress tests a plan in order to minimize regret across possible future scenarios. Making this shift would represent a fundamental change in mindset for the industry with far reaching dependencies on quantitative analysis tools and approaches as well as regulation, policy structure, and public engagement. 

Through this initiative, AEP50 will advance the state of the practice in the specification, development, and application of appropriate quantitative tools for DMDU. Of course, repurposing, reimagining, and renovating our models and approaches to support a DMDU type approach is a necessary, but not sufficient condition. Therefore, success of this initiative is dependent on and should be connected to other committees that are advancing planning under uncertainty from their perspective (e.g. regulation, policy, planning process).

This work will aim to build on FHWA’s TMIP work to promote planning and modeling with uncertainty as compiled in the recently published Transportation Planning for Uncertain Times report.  

To help get our arms around the topic and allow contributors to focus on their area of interest and expertise, the uncertainty initiative is organized into four key challenge areas:

Current Activities

 We still welcome volunteers to contribute to each of the challenge areas - please join the aep50 Uncertainty google group to connect and learn more.

TMIP-EMAT User Survey and Workshop

TMIP-EMAT is an open-source tool developed by the FHWA to facilitate exploratory modeling and decision-making under deep uncertainty (DMDU) approaches. As several years have passed since its initial release, we are now seeking feedback on its usage, potential improvements, and long-term maintenance.

The surveys linked below, along with the upcoming workshop, aim to evaluate current practices, gather user experiences and challenges, and prioritize future tasks if support becomes available. We welcome input from both experienced TMIP-EMAT users and those who have considered using it but haven't yet started.

TMIP-EMAT User Survey (est < 15 minutes to complete)

TMIP-EMAT Potential User Survey (est <3 minutes to complete)

Surveys are open until July 10.  A workshop will be scheduled later in the summer. 

Uncertainty Call for Papers: Getting Comfortable with Uncertainty

Example topics of interest include:

For any questions related to this Call for Papers reach out to Naveen Eluru ( or Marty Milkovits (

📚 Marty's Book Club: Transportation for Uncertain Times

🌐 The Idea:

Marty Milkovits and Flavia Tsang are leading a 'book club' of sorts, with the focus on delving into the Federal Highway Administration's Transportation Planning for Uncertain Times.  We are using the report's framing to discuss methods and tools for decision-making under deep uncertainty (DMDU) and then reconnect on a regular basis to share experiences.

🤝Why a Book Club?

This informal and collaborative setting provides us with the opportunity to: A) Share experiences implementing DMDU strategies in our agencies (or for our clients). B) Brainstorm ideas collectively. C) Develop additional materials that could assist others on a similar path. D) Foster a supportive community focused on advancing DMDU practices.

🧠What to Expect:

The format is flexible, with discussions ranging from the practical application of the FHWA report to identifying potential gaps, and creating materials to support the broader community.

Book Club Structure and Timing

Previous Activities