uses of travel demand models beyond the mtp · 2017. 1. 4. · uses of travel demand models beyond...
TRANSCRIPT
Uses of Travel Demand Models Beyond the MTP
Janie Temple Transportation Planning and Programming Division
October 12, 2011
Presentation Outline
What is a Travel Demand Model?
Cautionary notes on using models Typical Uses Emerging Uses Innovative Uses
What are Travel Demand Models
Travel demand models (TDMs) are
developed to simulate actual travel patterns and existing demand conditions in an urban area or region.
Travel Demand Modeling
Forecasts are used to develop
information to evaluate the effects that known and projected changes in socioeconomic conditions may have on the demand for travel on the urban area's major roadway and transit systems.
The Travel Demand Modeling Process
Trip generation
Trip Distribution
Mode Choice Traffic Assignment
Notes on using TDMs - Application Consistency
Model construct must be consistent with The requirements of the analysis. For example, sketch planning models are appropriate for analyses to evaluate and select specific transportation alternatives for further analysis but would be inconsistent with the analysis requirements for estimating toll revenue.
Application Consistency
Consistency between model framework and analysis requirements is necessary to ensure that the model is not used in a way that is inconsistent with the theory on which it is founded.
Notes on using TDMs - Reasonableness Checks
Reasonableness checks should be part of model development and analyses standard practice because there are many opportunities for introducing erroneous data, omitting information, or misunderstanding models and analyses.
Reasonableness Checks
Input data Calibration/Validation data Evaluate each model step results Evaluate final model results Sensitivity testing
Notes on using TDMs - Benefits
Known input and analysis parameters Allows comparison of alternatives Baseline and alternatives can be easily
compared Results can be replicated Results can be compared to other data
sources such as Census data
Typical Uses of TDMs
TDM output is used by TxDOT, MPOs, and local governments to:
Develop or update the metropolitan
transportation plan Program projects for additional study Rank projects for the Transportation
Improvement Program Emissions analysis in non-attainment areas
Typical Uses of TDMs
Evaluate system improvements Identify system deficiencies Conduct Alternative analysis Supports future design level traffic
development
Typical Uses of TDMs – GIS Databases
The model input data consists of three primary databases for both base and forecast years.
Network database Traffic analysis zone database Demographic database
Using TDM Database Road Network in Tyler, Texas
Using TDM Databases – Employment in Tyler, Texas
Using TDM Results – Travel Patterns in Tyler, Texas
Using TDM Results – Volume to Capacity Ratios in Tyler,
Texas
Emerging Uses of TDMs
Linking planning and environmental Traffic operations analyses HOV Analysis Toll and HOT analyses Transit analyses
– New/Small Starts Applications Needs based analyses
– TMMP/TUMP
Planning and Environmental
TDMs may be used for planning and environmental linkages: Statewide Implementation Plan development Conformity emissions analyses Air quality studies and analyses
– TCM evaluations – Hot spot analyses – Mobile Source Air Toxics analyses
Planning and Environmental
Indirect and cumulative impact (ICI)
studies - used at least as baseline Socioeconomic analyses
(demographics and land use) - used at least as baseline
Regional toll analyses
Planning and Environmental
Alternatives analyses (traffic
redirection studies) Land use information may also be
used to help assess water quality and biological impacts
Need and purpose
Operational Analysis
TDMs – Macro scale – Regional travel
patterns – 24 hr/daily demand – Typical weekday
travel – Simplified network – Link volume output
Simulation Models – Micro scale – Addresses dynamic
aspects of traffic – Incremental
demand – Detailed network – Capacity restrained – Provides network
delay
Operational Analysis
TDM and simulation models are used together to accomplish operational Analysis. Simulation model inputs include: The regional TDM Local travel survey data
Innovative Uses of TDMs
Evaluate alternate growth scenarios Evaluate major transit projects Evaluate major land use changes Link to land use models Link to economic models Link to the Statewide Analysis Model Link to other freight or truck models
Innovative Uses of TDMs
Commuter rail studies using planning models and the Statewide Analysis Model
Evaluate hurricane evacuations Evaluate impacts of floods Evaluate smart growth impacts Evaluate alternate funding scenarios
Conclusions
Travel demand models are powerful tools
Travel demand models can be utilized in transportation planning in innovative ways
Understanding the model is critical to producing effective analyses
If you need additional information
For questions about the development
or uses of the travel demand model, please contact one of the following people:
Contact Information
Janie Temple (512) 486-5107
Greg Lancaster (512) 486-5126