Lead Presenter Biography

Stella Nepal is an Assistant Research Scientist at the Texas A&M Transportation Institute. She has been with TTI for 16 years. She specializes in the analysis of Workplace and Special Generators survey data collected in Texas urban areas and statewide under TxDOT's Travel Survey Program. She works remotely from Canada. Stella has made it her mission to find ways on how the Texas Travel Survey Data can be utilized outside the scope of modeling and remain an important asset to TxDOT's transportation planning and modeling needs.

Co-Authors

Presentation Description

In travel demand modeling (TDM), some workplaces exhibit atypical behavior such that regionally estimated trip rates cannot reasonably describe their trip generation numbers. In many study areas, key special generators are identified and surveyed separately to develop information specific to each site for use in the TDM. Inevitably, not every special generator is surveyed prior to a model development effort due to fiscal constraints or failure to identify a special generator site during survey planning. The standard solution for unsurveyed special generators is the application of trip rates from the Institute of Transportation Engineers (ITE) Trip Generation Manual, which provides a national index of trip generation data stratified by land use code. This information includes basic statistics and simple linear model fits, where appropriate, meant to assist decision making regarding trip generation behavior for unsurveyed sites. However, it is well-recognized that these published ITE rates have become outdated and have proven to yield under or over-estimated trips.

Researchers propose that a decision-making tool for special generator development based on Texas-specific site data is a better alternative for modeling efforts across the state. Developing a data analysis and visualization tool using Power BI offers a unique advantage in Texas, where the majority of Metropolitan Planning Organization model information is housed in a single Sharepoint location. Power BI reporting is easily embedded on a Sharepoint. This presents an opportunity to implement a dynamic, multidisciplinary data visualization project powered by a database containing statewide special generator survey information.

The tool is modeled after the ITE Trip Generation Manual, but this innovative approach allows the user to dynamically subset the Texas special generator database based on attribute such as model area size, site type, and site employment. The report develops general statistics and provides a simple linear model fit which automatically update based on the user’s selection criteria. The tool also provides map displays of key special generator establishment data as well as observed travel characteristics of employees and visitors (i.e. trip purpose, travel modes, trip origins and destinations, etc.) that can be compared across regions of different urban forms. With a statewide database that is envisioned to include the workplace surveys implemented under the Texas Travel Survey Program, the tool can perform queries on specific type of establishments that can further assist in identifying under-represented NAICS groups and advance model development efforts. 

Presentation File