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Introduction to TREDIS

Objective of This Document

This TREDIS User Manual describes how to use TREDIS 6 and some best practices for using it as a decision-support tool. Additional practical support for using TREDIS is provided through context sensitive help screens. Other support documents are available on our website for a few special topics and to provide background on the theoretical development and data sources associated with TREDIS.

Note that TREDIS 6.0 is supported for use with the latest versions of Microsoft Edge, Chrome, and Firefox. If you are using any other means to access the platform, some features and functions may not work correctly.

Overview of the Purpose and Use of TREDIS

TREDIS is a decision-support tool that compares two "alternatives," that is, two possible futures, and shows the difference in economic impact and social benefits between those two alternatives. In most cases, the comparison will be between two mutually exclusive options, such as "build a new facility" or "don't build the new facility." In addition to a benefit-cost analysis (BCA) and economic impact analysis (EIA), TREDIS provides other reports that validate the results and provide additional context, as well as functionality that supports grant applications.

There are three major parts to setting up a TREDIS analysis. First, the dimensions of the analysis are defined, and the user selects the two alternatives, the time periods considered, the geographic units used, and the modes modeled. Second, the user provides data on travel behavior associated with each alternative (and, if desired, other data to support a market access or contingent development analysis). This is often done with the support of a travel demand model or sketch tool, but those are not strictly necessary. Third, the user needs to confirm the default factors that TREDIS provides for analysis – among them, operating costs, freight volumes, and other travel-related rates and levels – or overwrite the defaults with their own values.

Following the analysis run, TREDIS provides extensive reports that show BCA and EIA results in great detail, as well as supplemental reports providing greater support for further analysis. Reports in both BCA and EIA demonstrate the difference in expected outcomes across several years – each estimated individually – between the two alternatives defined.

Logging into TREDIS

Using your web browser, access TREDIS at login.tredis.net. Provide your user name and password in the appropriate spaces on the Login Page, as illustrated in the following figure.

Note that the first time you login to the TREDIS software, you will be prompted to accept the terms of use and to change your password.

The Login Page
The Login Page

Note that the first time you login to the TREDIS software, you will be prompted to accept the terms of use and to change your password.

Once you are logged in, the products for which you have subscribed will be shown in color, while those that are not subscribed will be in black and white monochrome.

The Product Page
The Product Page

From here, click on the TREDIS icon to open TREDIS. You'll land on the Project page to start with.

Every TREDIS project follows the steps as shown in the navigation bar.

The Navigation Bar
The Navigation Bar

Click the name of a page in the Navigation Bar to navigate to that page. Once a project is created, you will need to finish work on each step in order, left-to-right. Once all data has been initially entered, you can freely move between pages to view and edit data.

  • Project. Choose a project, start a new one, set project-level preferences, or manage projects.
  • Timing. Set the construction and operations periods for the project and distinguish separate segments of travelers.
  • Regions. Define regions using a map to create the economic model.
  • Modes. Choose modes and purposes.
  • Costs. Enter capital, maintenance and other building costs by facility.
  • Travel. Input primary travel characteristics (trips, VMT, and VHT) and adjust rates and flows as needed.
  • Access. Provide market access changes (if desired for your analysis) or add ad-hoc economic changes expected.
  • Results. On first view, select analysis parameters and start run. Once run, see all reports and model outputs.

Note: Do not user the back button on your web browser as this may prevent proper data loading. Instead, use the tabs in the Navigation Bar to move between pages in TREDIS.

Getting Help and the Navigation Menu

The three-bar icon (or "hamburger" icon) that is always visible in the upper-right of a TREDIS window is called the Navigation Menu. The following options are available:

  • User Documentation. Technical and user documentation site that includes a link to this document.
  • Preferences. Opens the Preferences Window.
  • Help. Opens a section of the User Manual relevant to the screen you are currently on.
  • TREDIS User Manual. Opens a new browser window with the full User Manual.
  • Sample Import Spreadsheet. Downloads the current version of the Import Spreadsheet.
  • Product Menu. Directs you to the Product Menu screen, with tiles highlighted depending on your user licenses.
  • Log Out. Logs out and returns you to the login page.