The Transportation Revenue Estimator and Needs Determination System (TRENDS) model funded by the Texas Department of Transportation is designed to provide transportation planners, policy makers and the public with a tool to forecast transportation revenues and expenses based on a user-defined level of investment at both the state and local level. The user, through interactive windows, can control a number of variables related to assumptions regarding statewide transportation needs, population growth rates, fuel efficiency, federal reimbursement rates, inflation rates, taxes, fees and other elements. The output is a set of tables and graphs showing a forecast of revenues, expenditures and fund balances for each year of the analysis period based on the user-defined assumptions. The TRENDS model also includes a local option sub-model for each of Texas’ 25 Metropolitan Planning Organizations. Through the local option model the user can analyze changes in local revenues by creating or adjusting a local fuel tax, local vehicle miles traveled tax, local vehicle registration fee or the local fuel efficiency rates.

1. The Transportation Revenue Estimator and
Needs Determination System (TRENDS)
model funded by the Texas Department
of Transportation is designed to provide
transportation planners, policy makers and the
public with a tool to forecast transportation
revenues and expenses based on a user-defined
level of investment at both the state and local
level. The user, through interactive windows,
can control a number of variables related to
assumptionsregardingstatewidetransportation
needs, population growth rates, fuel efficiency,
federal reimbursement rates, inflation rates,
taxes, fees and other elements. The output is a
set of tables and graphs showing a forecast of
revenues, expenditures and fund balances for
each year of the analysis period based on the
user-defined assumptions. The TRENDS model
also includes a local option sub-model for each
ofTexas’25MetropolitanPlanningOrganizations.
Through the local option model the user can
analyze changes in local revenues by creating
or adjusting a local fuel tax, local vehicle miles
traveled tax, local vehicle registration fee or the
local fuel efficiency rates.
As new data become available the TRENDS
model is updated to reflect the new infor-
mation. Variables that are maintained and
updated on a regular basis include:
trends-tti.tamu.edu/
T.R.E.N.D.S. MODEL
• TxDOT cash flow forecasts
• Agency fund transfers
• Letting volume information
• Bond sales and debt service
• Population
• Fuel economy
• Vehicle registrations
• Construction cost inflation
• Vehicle miles traveled
• Other critical variables as necessary
Saving Lives, Time and Resources tti.tamu.edu

2. David Ellis
SHRB, Room 336
(979) 845-6165
d-ellis@tamu.edu
Brianne Glover
SHRB, Room 332
(979) 458-0919
b-glover@tamu.edu
TTI1726.3896.1216
Texas A&M Transportation Institute
3135 TAMU
College Station, TX 77843-3135
http://tti.tamu.edu/group/finance/
To solve transportation
problems through research,
to transfer technology and
to develop diverse human
resources to meet the
transportation challenges of
tomorrow.
TTI’s Mission
Contact
TTI’s Mission
The Texas A&M Transportation
Institute, established in 1950,
seeks solutions to the problems
and challenges facing all modes
of transportation. The Institute
works on over 700 research proj-
ects with over 200 sponsors in the
United States and abroad at all
levels of government and in the
privatesector.TTIisrecognizedas
oneofthefinesthigher-education-
affiliated transportation research
agencies in the nation. TTI has
saved the state and nation billions
of dollars through strategies and
products developed through its
research program. TTI research
has a proven impact — resulting
in lives, time and resources saved.
About TTI
Outputs
Revenue and Expense Tables and Charts
Revenues and Expenses by Category
Local Option Revenue Reports
User Controlled
Variables
State Gas and Diesel Tax Rates
Federal Gas and Diesel Tax Rates
Fuel Tax Indexing
Vehicle Registration Fees
Vehicle Miles Traveled (VM) Fee
Local Option Fees
Population Growth
Fuel Efficiency
Inflation Rates
Maintenance Scenarios
Local Construction Allocations
Economic Impacts