Select a question topic:
Modes and Travel Inputs
Regions and Geographies
General and Other Questions
Modes and Travel Inputs
Question: How does TREDIS deal with year-by-year travel data?
Answer: Beginning with version 5.0, TREDIS will have the ability to enter year-by-year travel demand data in Advanced Mode. Users will be able to enter all inputs for each year of their analysis period, thus not requiring any growth rate interpolations.
Question: How does TREDIS handle complete streets projects, or bicycle and pedestrian projects?
Answer: A complete streets project would reflect changes in VMT and VHT, with likely mode shift changes from automobile to transit or non-motorized modes. TREDIS would estimate the benefits of these changes. TREDIS also enables users to enter bicycle and walking as a mode choice, and enter the commensurate data for that mode. Projects that increase bicycling or walking experience health-related benefits to the increased bike and walk use, in addition to any mode-shift benefits.
Question: What is the "Percent of Trips that are Locally-Based" used for and how are values determined?
Answer: TREDIS is looking for the percentage of the total trips in the preceding columns that originate and terminate within the study region. TREDIS uses this for calculations involving trips internal to the study region.
Question: Can TREDIS evaluate effects of active transportation and non-motorized modes (bike/pedestrian) as project elements?
Answer: Yes, TREDIS includes pedestrian and bicycle modes of transportation.
Question: How can our regional travel demand model results affect the economic impact and benefit cost results in TREDIS?
Answer: Travel demand models may show changes in traffic volume, vehicle-miles of travel, vehicle-hours of travel and volume/capacity ratio. TREDIS can translate such changes into effects on costs, reliability, safety and traffic volumes. Travel demand models may also generate travel time skims that can be used to measure changes in the number of zones that are effectively within the bounds of labor market and same-day delivery market areas.
Question: How might you measure connectivity and access in rural areas? Within or outside of TREDIS?
Answer: TREDIS has input forms for users to put in measures of the effect of a project on travel times to intermodal facilities, as well as changes in labor market areas (commuters living within 40 minutes of employment centers) and delivery markets (business activities within same day delivery areas). Given those inputs, TREDIS then calculates the agglomeration and connectivity effects on business productivity, and hence regional competitiveness and economic growth.
Question: Does TREDIS handle cross-modal analysis such as rail vs. highway capacity?
Answer: Yes, the multi-modal characteristics of TREDIS make it ideal to assess both complementarities and tradeoffs among alternative modes. For instance, TREDIS was used to compare alternatives for rail freight vs truck freight options for the I-95 Corridor Commission, and it was used to compare rail vs bus and car options for regional corridors in New Hampshire, Massachusetts and Ontario.
Question: Is there an interface between TREDIS and TransCAD or other travel model platforms?
Answer: TREDIS has three options for this interface. One is a manual cut-and-paste of TransCAD-generated results into a TREDIS form. The second is a script that automates the pass-off of information. The third is to use the TREDIS API (application programming interface) to fully automate the entire process.
Question: Which travel demand model software is TREDIS compatible with?
Answer: TREDIS is designed so that it can optionally work seamlessly with any type of travel demand model. For instance, it has been successfully used in recent studies with TransCAD, EMM2, Cube Voyager, and VISSUM.
Question: Does the model come pre-loaded with transportation network data?
Answer: TREDIS does not come with any transportation network model. Rather, TREDIS is designed so that users can run TREDIS in a “sketch planning” mode without any transportation model, though it also gives users the option to pass data from their own transportation model to TREDIS.
Question: What would the general procedure be for use of TREDIS for a water port improvement project?
Answer: The general procedure is to create a project to represent the upgrade and compare it with the base case. It will require user creation of the upgrade project. An important input will be the difference in truck freight (and/or freight carried by water vehicles). If, as is likely, the additional freight to be carried by water vehicles is mostly bulk and/or containers, some adjustment to the default value of time should be considered.
Question: What would be the general procedure for use of TREDIS for an airport improvement project?
Answer: The general procedure is to create a project to represent the upgrade and compare it with the base case. It will require user creation of the upgrade project. An important input may be in the difference in access to intermodal facilities.
Question: Does the model account for investments in greenfield vs. existing areas? Is there a bias toward always building in new areas?
Answer: TREDIS is a regional economic impact model with a strong set of data on regional economic conditions and competitiveness factors. TREDIS can thus show how enhancement in market access conditions can help grow jobs in a region’s economy. However, TREDIS is not a localized land use model, and it has no information on localized zoning, topography, water/sewer availability or incentive factors that affect where development occurs. However, it is possible for a TREDIS user to define alternative scenarios in which different types of transportation investments lead to different costs and benefits as a consequence of user-presumed shifts in land development patterns. And then TREDIS can show the overall regional economic development consequences of those scenarios.
Question: I am concerned about the "perversity" of transportation projects. These projects are intended to facilitate development. But, if successful, they often lead to higher land prices that chase away development (especially affordable development) to cheaper and more remote sites. Thus transportation projects can lead to sprawl. Using value capture can help mitigate this situation. Does TREDIS show the different impacts of a project depending upon whether or not value capture is used?
Answer: While local access connectors can facilitate development at specific sites, most investments in transportation corridor and terminal projects are made in response to demand for mobility associated with the delivery of goods and services, commuting to work, shopping, tourism and other human activities. Systems such as TREDIS provide a means of accounting for the economic efficiency of enhancing mobility, and the allocation of benefits. Transport investments (including rail lines, bus lines and roadways) may support sprawl, or they may support higher density development in central city locations, depending on where they are located and what kind of trips they serve. The benefit-cost module in TREDIS can be used to account for those differences. Value capture is usually considered a means of project financing, achieved by collecting a portion of the increased value of land occurring in areas surrounding new rail transit stations (rather than as an anti-sprawl policy). TREDIS has a finance module that can account for the reallocation of dollar flows associated with value capture.
Question: Can TREDIS be used to determine the impacts of a Road Diet project?
Answer: Yes, TREDIS can be used to assess impacts of a “road diet” project – i.e., a project that controls or reallocates space available for cars, trucks, buses, bicycles and pedestrians. The only requirement is that the analyst supply information on alternative scenarios that lead to differences in the volumes of affected parties using each mode, and differences in the mobility and accessibility conditions that they receive as a result of that project.
Question: Is TREDIS able to provide economic impact/benefit analysis for projects that involve taking an automobile-centric transportation system and increasing the diversity of modes in that system (pedestrians, bikes, transit)? i.e., would TREDIS recognize economic impacts and benefits of a road diet project, or is TREDIS set up to only assume benefits when the transportation system is expanded for automobiles only?
Answer: TREDIS is a framework for assessing regional economic impacts that is multi-modal and “mode neutral.” It allows for scenarios that may involve benefits generated and costs incurred across combinations of modes, including bus, light and heavy rail transit, commuter rail, bicycle and roadway facilities, as well as air and marine transport. Impacts of each mode can also be distinguished. This can include impacts from changes in travel time, cost, access, connectivity or externality factors such as air quality.
Question: Are there inputs for parking? For example, a road widening may reduce on-street parking.
Answer: Yes, TREDIS does provide for the impact of parking policies by allowing the analyst to enter changes in the time and cost of automobile use for various classes of trip purpose to various study area zones. However, TREDIS does not directly estimate how auto travelers respond to a reduction in parking, since only the analyst can provide input information on the characteristics of available travel options and how travelers respond to changes in the cost and performance of those travel options.
Question: How do you prioritize and rank a list of Highway Projects? Do you have to run each project individually and then compare benefits?
Answer: TREDIS is set up to directly compare alternative policy, program or project options for a given corridor or study area. It is also used by various state DOTs and MPOs to prioritize various projects that have been proposed for different corridors. That is usually accomplished through use of an external spreadsheet or database to store the various projects.
Question: Can you analyze highway prioritization projects or only capacity improvements?
Answer: TREDIS can analyze the economic impacts and benefits of any kind of transportation project as long as it has some measureable effect on volumes, speeds, distances, reliability, energy use, air quality or modal use. This includes capacity projects, safety projects, preservation projects or other functional enhancement projects for any mode of transportation including air, rail, marine, road/transit or non-motorized mode.
Question: To use TREDIS, how much effort is involved to get required data on vehicle on factors such as the economy, vehicle occupancy and tonnage?
Answer: A TREDIS subscription comes bundled with a large dataset on characteristics of your study area or areas, including county and state data on employment, income and other economic patterns, the size of accessible labor and delivery markets access, relative prices, etc. In addition, TREDIS comes already set up with average values for passenger occupancy of vehicles, freight tonnage levels, etc., though the user has fully capability to change any of those values if desired. The bottom line, then, is that TREDIS can be used immediately upon start of your subscription.
Question: Please make it possible for us to adjust the mode labels so that we can distinguish commuter rail, intercity rail and rail transit as alternatives.
Answer: You can already redefine available mode-purpose slots to represent alternative variants of those modes. However, the ability to freely and fully change the mode and purpose labels and features will be added in a future release.
Question: Can you add listings of the names of the airports and intermodal terminals that are being used for measuring access times?
Answer: Yes. These are being added to "Supplemental Report B" next to the appropriate access value. Now active for v3.3
Question: Do you have to make any alterations for left- or right-side drive?
Answer: No alterations are needed for TREDIS to analyze left or right-side drive vehicles.
Question: How does TREDIS capture reduced infrastructure costs and property value increases from compact and transit-oriented development?
Answer: Depending on the local setting and the form of proposed transportation project, there may be either positive or negative changes in other public operating costs. TREDIS provides input for such factors for consideration in benefit-cost and financial reports. Economists normally consider property values to be a measure of economic asset value rather than economic output (money flow), and a reflection of the greater productivity of affected locations. In other words, property value increases cannot be added to money flow increases, though TREDIS will estimate growth in jobs and income as a result of greater productivity (enhanced access and/or reduced location costs) in affected locations.
Question: How are the environmental impacts assessed of the various alternatives? Can TREDIS analyze benefits related to expansion of a bike-commuting network?
Answer: TREDIS has a built in calculator available to estimate the air quality impacts of changes in usage, distances and speeds for alternative transportation projects spanning air, marine, rail, road, transit and bicycle modes. However, there is also an input for separate user calculations of environmental impacts, which can supersede these calculations and encompass broader forms of environmental impact.
Question: Can TREDIS analyze benefits related to expansion of a bike-commuting network?
Answer: Yes, TREDIS is designed to work for bicycle projects, and indeed it has been used by state DOTs for bikeway projects.
Question: Is TREDIS recommended for use in projects such as Intersection reconstructions?
Answer: There are many cases of TREDIS being applied to intersection simulations, including clients that include both corridor and intersection projects in prioritization plans.
One of the challenges with simulation models is that they usually run for only peak periods and consequently it is necessary to identify a method for extrapolating impacts to a daily level before annualizing for input into TREDIS. Annualizing benefits may also be very difficult because the number of vehicles tested in a simulation may not correspond to actually affected volumes.
Other differences from TDM-based analysis may be less importance of congestion (which is basically the operating cost difference of stop-and-go conditions vs free-flow condition) and better estimation of improvements in buffer time/reliability, based on speed distributions. Unless there are major geometry changes like roundabouts or changes to highway interchanges, VMT may also be less of a factor, while VHT changes remain important.
These are just some different things to keep in mind when preparing TREDIS inputs for intersections. This analysis is certainly possible.
Regions and Geographies
Question: Does TREDIS have the ability to deal with small-scale projects such as an arterial expansion?
Answer: TREDIS is able to assess projects of all scales. As long as the user has appropriate inputs, TREDIS will calculate the respective benefits and economic impacts of the project.
Question: What is the smallest geography TREDIS uses for SE data? Census Track? Block Group? Zip Code?
Answer: Depending on your subscription, TREDIS is able to analyses regions at the national, state, county, and zip code level. Study regions are defined by choosing one or more entries from these categories.
Question: Any international applications thus far outside of Canada and Australia? Are you stepping up your marketing in overseas markets?
Question: Can TREDIS be used to evaluate projects outside U.S.?
Answer: Yes, TREDIS models are currently in use in the US, Canada and Australia, and TREDIS is designed to enable use in other countries in the future, including those with different measurement and currency units.
Question: Does TREDIS analysis vary by county in USA?
Answer: Yes, the economic impacts of any given transportation project can be very different depending on local economy, labor market size, profile of commuter occupations and industries, mix of business activities, profile of freight being shipped in and out, and unemployment rate.
Question: What is an appropriate project size that would benefit from TREDIS analysis? $1 million? $10 million? $100 million?
Answer: The Benefit-Cost Analysis element of TREDIS can be useful for projects of any size. However, if the project is small (for instance, under $3 million), then the economic impact analysis element of TREDIS is unlikely to show any appreciable effect on regional economic growth.
Question: Has TREDIS been used by rural planning organizations before?
Answer: TREDIS has been used by the Appalachian Regional Commission to calculate the economic benefits of improving rural access and connectivity.
Question: What's the smallest level of geography (smaller than region) that TREDIS has been utilized?
Answer: TREDIS study areas can be defined as any combination of zip codes. In practical application, TREDIS has been successfully used for assessing economic impacts on towns of around 10,000 population or greater.
Question: Is there any integration of TREDIS with GIS?
Answer: TREDIS is built to work with GIS systems. The database of intermodal facilities and travel data have spatial location tags, and TREDIS also derives market access measures by querying a GIS system to calculate population size within labor market areas and business activity within “same day” truck delivery areas.
Question: Are the preset data tied to the project region? Or are they just typical national figures?
Answer: TREDIS comes preloaded with both kinds of data. It comes with national default factors for vehicle operating cost, fuel economy, average occupancy, etc. (by type of vehicle), though all of these factors can be changed by the user if desired. In addition, TREDIS comes with a large database of county specific data concerning employment, income, occupation, business output, freight shipment and market access characteristics, which can be adjusted if desired.
Question: Can you simply get a regional baseline forecast without a specific project comparison?
Answer: Yes, TREDIS reports can show the baseline, the alternative scenario in which a project or program is implemented, and the difference between the two, which is the measure of incremental impact.
Question: Since commodity data is at the state or county level, how do you break down the commodity profile for a single community or corridor?
Answer: TREDIS comes pre-loaded with state-level commodity data (from the Freight Analysis Framework database). However, these defaults may be overwritten with more detailed data. For example, if the user has access to Transearch data, then commodity flows and mix information can easily be entered with county-level detail. In the present version of TREDIS, this level of detail is user-generated, although we are working to provide it as a default database in future versions.
Question: If we study impacts on one metro area, does TREDIS allow for impacts on adjoining areas or do we assume that all benefits are confined to the study area?
Answer: The answer depends on how you set your project up. If your project has a single Study Region, then economic impacts are confined to changes in activity in your region. However, Benefit/Cost ratio results can be viewed from either perspective: Study Region only, or National perspective. The difference between these two perspectives has to do with how travel flows through your study area. If your study area has any incoming, outgoing, or through travel (as input in the Travel Demand Characteristics page), then benefits will “leak out” of your study area and accrue to households and businesses elsewhere. On the Benefit/Cost report, the “Study Area” perspective excludes these benefits, whereas the “National” Perspective includes them.
Question: Does TREDIS estimate different benefits for an interchange in the middle of nowhere vs. one on the fringe of urban development?
Answer: TREDIS can estimate the economic consequences of an interchange located anywhere, as long as the analyst provides input data on how the project will affect traffic levels and travel conditions. For instance, it may show that an interchange between two highways that is located in a rural area will have no benefit to residents of the local area, but will benefit long-distance truck movements for industries located hundreds of miles away.
Question: How large or small a study area can be handled by TREDIS?
Answer: TREDIS can work for areas as small as individual cities and as large single as major regions of North America. Examples to date range from as small as the municipality of LaPorte, Indiana to as large as a 13-state Appalachian Region of the US.
Question: Can TREDIS be used for multiple study areas?
Answer: Yes. Normally, a subscription is set up to include all counties in a given region, state or group of states, and then the user can select individual counties or aggregations of counties as desired to represent metropolitan or regional jurisdictions, highway or rail corridors, etc. TREDIS normally works with a multi-regional economic modeling system that can show how transportation projects in one region can affect the economy of other adjacent regions.
Question: How does size of the study area affect the economic impact measurement? Doesn't it bias the results?
Answer: The area selected does affect impact measurement, but it is NOT a bias. In general, expanding the scale and breadth of a study area will tend to increase the gross economic impact. That occurs for several reasons. First, it increases the portion of affected travel movements (trips) that are "locally-based" -- i.e., having a local origin or destination and hence a direct effect on households or businesses. Second, it expands the observed economic "multiplier" effect -- i.e., the indirect impact on suppliers to affected businesses, and the induced impact from consumer respending of worker income. On the other hand, expanding the study area to be overly large will tend to make some of the business attraction moves appear to be just relocations within the same area. Each of these different effects is fully captured and measured within the TREDIS framework.
Question: We work with border and international initiatives. Can TREDIS be used to evaluate projects outside U.S.?
Answer: TREDIS models are actively used throughout Canada and the US. They are built to be sensitive to factors such as time, cost and distance for travel to and through international borders and air/sea/land gateways. In addition, a new international trade element allows for local impacts associated with changes in the international cost competitiveness of export industries.
General and Other Questions
Question: I forgot my password for my TREDIS login. How do I recover it?
Answer: Go to the login page. Click the “Forgot password?” link below the login button. You will be prompted to enter your username and can re-set your password.
Question: Where does the user acquire the necessary inputs for TREDIS? Can these inputs be changed after running a scenario?
Answer: "Travel demand inputs are most frequently provided by an agency's travel demand modeling staff or other engineering estimates. When detailed entry is not available, TREDIS has a user-friendly interface that enables the user to enter assumptions about traffic and travel growth. These assumptions may be changed at any time. Alternatively, a user may wish to copy a scenario and change the travel inputs to test sensitivities.
Please see our technical documentation as this depends on the type of project you are assessing. In general, TREDIS requires the user to provide information on trips, VMT, and VHT (or speed), and average vehicle occupancy. For transit modes, additional information such as passenger-trips, passenger-miles, passenger-hours may be required."
Question: How difficult it is to get the required data for TREDIS?
Answer: TREDIS comes pre-loaded with default values which come from a variety of federal sources. Brief descriptions, reference information, and acceptable ranges of values are cited for each default value within TREDIS. All of this information is contained in the TREDIS® Data Sources and Default Values document under the TREDIS Reference Documents within the TREDIS User Resources link.
TREDIS also builds upon economic data from the US Bureau of Economic Analysis and US Bureau of Labor Statistics, demographic data from the US Census Bureau, interregional network impedances from Oak Ridge National Laboratories, domestic trade flows from Implan, international trade flows from WiserTrade, traffic and commodity flows from the Federal Highway Administration (FAF), baseline forecasts from Moody's Analytics, environmental factors from the US Environmental Protection Agency and the US Department of Energy, and spatial market data from ESRI. All of this data is built into TREDIS; there is no need for the user to obtain any further data other than inputs to describe the policy, project, or program to be analyzed.
Question: Are there consulting services to assist me in running TREDIS?
Answer: EDRG also offers consulting services for project evaluation by running TREDIS in-house for project engagements. Contact us to see which option applies for your next study.
Question: How much does TREDIS cost? Can MPO's or contractors access a state DOT's TREDIS account?
Answer: TREDIS is offered as a subscription for periods as short as three (3) months and may extend to multiple years as needed. All TREDIS subscriptions include comprehensive support and no-charge updates as new versions of TREDIS are made available.
The TREDIS Partner Program enables a State DOT to leverage its TREDIS subscription by offering affiliated MPOs the ability to also access its TREDIS setup. Some state DOTs and MPOs have ongoing subscriptions to TREDIS, which allows them to offer TREDIS access to their contractors at little or no added cost (as long as the work is directly for that client). Other state DOTs and MPOs have decided to have their contractors take out a separate TREDIS subscription for each project that requires its use. In the latter case, there are low cost subscriptions for one-time studies.
Question: Do you offer training programs at sites other than at your HQ in Massachusetts?
Answer: We typically provide training using a web meeting and have found this method to be highly successful, eliminating the need for travel. Training is included with a TREDIS subscription. Contact us for details.
Question: Any international applications thus far outside of Canada and Australia? Are you stepping up your marketing in overseas markets?
Question: Can TREDIS users evaluate multiple projects at one time?
Answer: Yes. The standard TREDIS subscription is enabled with the ability to import multiple projects at one time. This functionality is located on the Project Management page when you are logged into your TREDIS account. Simply click the “Import Projects” button and browse to your spreadsheet to initiate the upload. TREDIS subscribers have used this to import anywhere from a few projects at a time to over 1,000 projects at once. There is no limit to the number of projects that can be imported. The amount of time that the import takes depends upon the number of projects as well as their complexity.
NOTE: Customer support can assist you with the proper format of your spreadsheet.
Question: Can a user view other user's projects/scenarios or restrict them from seeing yours?
Answer: The default setting for all projects is “private.” At this time if you change the project status to “shared,” you are sharing with all users who have permission to log onto your account.
Question: Is it easy to share your scenario results with others?
Answer: Yes, You may allow another user in your organization to view and copy a project. Just click the properties button on the project page and click the SHARE radio button.
Question: Can other users change data in my projects?
Answer: In order to ensure data integrity, only the owner (original creator) of a project can change data in that project. If a project is “shared” with other users, those users may make a copy of that project and make changes to their copy.
Question: Can a user archive projects/scenarios? If so, how long can they stay in the system?
Answer: TREDIS users can name and re-group projects/scenarios associated with their username. You can simply create a group called “archived” (or whatever you choose) so that they do not appear in your active project lists. As long as the TREDIS account and username are active, the user will have access to the projects.
Question: Does TREDIS back up the system?
Answer: The TREDIS system is backed up nightly in case of catastrophic failure. We recommend that users create a project backup and store their own projects offline. Individual projects cannot be retrieved if deleted.
Question: Where are the scenarios that a user runs in TREDIS saved?
Answer: Your projects are saved in your TREDIS login. You may access and organize your projects/scenarios in the project management section of TREDIS (first screen viewed after login).
Question: Can multiple individuals in separate locations logon TREDIS and run scenarios simultaneously?
Answer: Yes, TREDIS is a true multi-user system.
Question: Will TREDIS run slow if many people are in the system at the same time?
Answer:There should not be a delay in TREDIS use with multiple users logged in at the same time. The support team runs system checks on the overall system functionality.
NOTE: It is normal for TREDIS to take a few minutes to build the economic model or to run reports.
Question: What is used to identify or associate an individual to a username/login?
Answer: Each TREDIS user receives a username and temporary login. Upon initial login, the user must change his/her password. In order to set up a login for an individual, we need that person’s first and last name, organization
name, address, email address and telephone number.
Question: Will there be a review process annually to review the utilization of each username?
Answer: This is at the discretion of the primary account holder. This information can be provided to the primary account holder upon request
Question: Can the username expire or be renewed based on this annual evaluation?
Answer: Yes. The login can be transferred to another user as well. This is at the discretion of the subscribing organization.
Question: Can two or more people in a single organization share a username?
Answer: No. Only one person is associated with a TREDIS username/login.
Question: Can two names be associated with a username so that it automatically rolls over to another person if one person leaves?
Answer:No. In order to maintain data integrity and retain an active contact for customer support, only one person can be associated with a username/login. If a person leaves the organization, we can either transfer the login to another user or deactivate that login and create a new one for the new user. The decision on how to proceed is at the discretion of the subscribing organization.
Question: I lost my password, how do I get a new one?
Answer: Please click the Forgot Password link on the login page. Enter your username and an email with your password will be sent to your email address stored in the system.
Question: How does TREDIS compare to other economic analysis tools?
Answer: TREDIS was designed from the ground up to be unique. And there is still no other tool that provides both benefit-cost and economic impact analysis, covers all modes (and intermodal interactions) , distinguishes different types of freight, has user inputs for the full range of connectivity and market access effects, and provides results as viewed from different economic measurement perspectives.
Question: How should TREDIS be used to be consistent with federal requirements such as Executive Order 12893 and OMB Circular A-94?
Answer: In general consistency with federal requirements should be discussed with Federal officials. For example, in response to questions about discount rates to be used in the discretionary TIGER grants which were part of the American Recovery and Reinvestment Act, the guidance from the US DOT was to use both a 3% and a 7% discount rate. With respect to whether construction jobs should count or whether benefits from logistics should count in the benefit cost analysis, it would depend on the nature of the project and the nature of the funding for the analysis. In any case, the federal agency supplying funds should provide guidance. EDRG has worked with many different agencies and on many different projects.
Question: We want open access and collaboration among users within our state DOT, but we want to allow consultant use of TREDIS restricted to a single project. Is there a way to accomplish this?
Answer: Yes. When you add users in the initial setup, there are options to control viewing and copying access. That allows any one user to enable others in their same account to view only the projects or scenarios that they want to share. It also requires others seeing those datasets to rename them before using them, so that no one can accidentally overwrite anyone else's work.
Question: How difficult is it to come up with the inputs for this software?
Answer: TREDIS is a flexible system that can be run with a minimal set of inputs relying on data that is commonly available or can be easily estimated by the analyst. However, it also allows for a larger set of inputs for those users wishing to utilize travel demand and network simulation models to generate the inputs.
TREDIS provides default inputs for accident incidence rates and accident costs, but users are encouraged to put in their own localized information on accident incidence rates for projects intended to enhance safety.
Question: I am unable to enter data into the Cost input tables - the cell in which I am trying to enter a value is locked. This happens only in Internet Explorer.
Answer: With certain versions of Internet Explorer some features of TREDIS require to be run in Compatibility Mode, particularly some of the input tables. To add tredis.net to the compatibility mode list, follow the following steps:
Question: How do I stop the annoying popup every time I click on a table on the cost or travel characteristics pages asking me to allow access?
Answer: To change the way Internet Explorer accesses the clipboard without having to respond to a prompt each time, follow the following instructions:
Question: What training is available for new TREDIS users?
Answer: TREDIS subscribers get a web-based training session, quick start manual, detailed user manuals, pre-built example setups, and ongoing consulting assistance during the period of their subscription. In person training can be done, though users have consistently found that the system is sufficiently intuitive to use, so in-person training courses are not normally required.
Question: How does TREDIS calculate the Tax and Finance report?
Answer: The TREDIS Tax and Finance Report is generated by empirically-based tax information for local and state taxes provided by IMPLAN. Other taxes or user fees can be entered as an input, such as transit fares or tolls, and these fees will have impacts on the Tax and Finance report.
Question: Where do most people get the 40 minute job numbers?
Answer: TREDIS defaults for the Market Access 40 minute labor market is powered by ESRI Business Analyst, and the default numbers are specific to the region. These numbers are calculated from the center of the geography. However, all numbers are user-adjustable and can be recalibrated to reflect drive times to a specific point of interest.
Question: How does TREDIS measure land use impacts from TOD or transit projects?
Answer: TREDIS measures land-use impacts in two ways. First, the user input travel demand data likely would suggest changes in travel patterns if the modeler has allowed for land-use feedback. Secondly, for impacts such as land value around TOD stations, the "contingent development" feature of TREDIS can be used to account for development that would not occur without the project.
Question: Does TREDIS have a sensitivity or risk analysis capability?
Answer: TREDIS enables users to test various sensitivities of assumptions by entering different scenarios. With each scenario, a user can change the basic travel inputs, or can also adjust fixed factors such as the value of time or price of fuel, for example.
Question: How about adding risk/uncertainty in the cost benefit analysis?
Answer: We'll work on adding this feature in the future.
Question: Are the default cost values updated by the user, or by the TREDIS Software Group?
Answer: TREDIS provides a long list of default factors, which are preloaded to enable users to make immediate use of the system. These default factors have been reviewed by staff of USDOT and they are consistent with factors required for US TIGER Grants. However, users can overwrite any or all of them, if desired.
Question: Does TREDIS update the background data as needed?
Answer: The local economic data is updated annually, and this is done automatically via the internet server. But users always have the choice to keep their analysis going with the old version of data to maintain consistency with past and ongoing research.