TREDIS is an integrated system comprised of elements that work together as a total solution. It does not require any other analysis tools or models. Yet the system is also flexible so users can substitute their own analysis tools in place of some elements, or customize TREDIS to work with other planning and analysis tools.
Unlike “black box” methods, each of the key elements of TREDIS is well-defined and clearly documented, using techniques backed by peer-reviewed publications and approved by public agencies. The key elements are summarized below; see the resources section for further documentation.
This module translates changes in traffic volumes, vehicle occupancy, speed, distance, reliability, and safety into travel efficiency changes and direct cost savings for household and business travel. It applies practices for travel modeling and economic valuation that are widely accepted by metropolitan, state, and federal agencies. Unlike other models, the TREDIS Travel Cost Module fully covers all modes of travel and the widest possible range of fuel and vehicle types, as well as schedule and operating performance conditions.
This module translates changes in market access and intermodal connectivity into effects on agglomeration, dispersion, scale economies, and productivity for various industry sectors. It applies calculation methods backed by peer-reviewed publications for estimating wider economic impacts. Unlike other models, the TREDIS Market Access Module fully distinguishes effects on passenger access and freight access, for both local urban markets and same-day regional access markets, as well as connectivity to intermodal terminals.
This module calculates the net present value of project benefits and costs from the differing perspectives of federal, state, and local agencies. It avoids double-counting and follows the benefit-cost guidance of USDOT modal agencies and Transport Canada, and the internet guide to Transportation Benefit-Cost Analysis hosted by the TRB Economics Committee. Unlike some other models, the TREDIS Benefit-Cost Module fully complies with USDOT TIGER Grant rules. It has helped applicants successfully obtain funding through these grant programs
This module incorporates a dynamic, multi-regional economic-demographic model to estimate impacts on employment and income growth over time. The model accounts for changes in productivity, capital investment, labor supply and demand, employment and wage shifts, and population migration. It builds upon inter-industry buy/sell relationships and inter-regional trade flows from IMPLAN, demographic and economic model forecasts from Moody’s, geospatial data from ESRI and employment data from US BEA. It incorporates economic geography and econometric response factors to represent industry responses to changes in relative costs and scale of market access, as documented in peer reviewed publications. Unlike other models, the TREDIS Economic Adjustment Module fully represents equilibrium shifts in economic activity and induced population changes.
This module calculates the effects of transportation and economic changes on revenues, expenditures and cash flow for both private sector and public sector entities. It includes calculation of effects of changes in tolls, taxes and pricing of transportation services, as well as local, state & federal tax revenues resulting from projects, programs or policies. Unlike other models, the TREDIS Finance Module enables sketch planning assessment of PPP scenarios from both public and private sector perspectives.
This optional module shows the volume and type of freight moving into, out of, through, and within a given region that will occur because of a project or program’s impact on the economy. It translates changes in a region’s economic growth (which is represented in dollar terms) into freight tonnage flows, and changes in volume of trucks. Unlike other models, the TREDIS Freight Module shows impacts by commodity being shipped, by mode (air, marine, truck, rail), as well as by origin and destination within the US and abroad.