Our Student GRAs

Meet our current 2025 - 2026 Portland State University students working as research assistants for TREC staff and researchers. See past graduate research assistants (GRAs) here, as well as our PSU transportation scholars and fellows.

Pujitha Gali

Pujitha Gali 
Advisor: Tammy Lee 
LinkedIn

Pujitha is a graduate student in Computer Science at Portland State University with a background in Interaction Design. She's interested in the intersection of design and front end development, especially when it comes to building tools that make data more accessible and meaningful. She's working with advisor Tammy Lee on transportation data and website-related tasks. She is excited to be part of the TREC team!

Andrew HannaAndrew Hanna
Advisors: Nathan McNeil and John MacArthur 

Andrew is a graduate student in the Master of Urban and Regional Planning (MURP) program at Portland State University. He is currently supporting Nathan McNeil and John MacArthur in evaluating the Transportation Wallet: Access for All program. He is interested in how planning practice can promote thriving communities.

 
Joe KortenhofJoe Kortenhof
Advisors: Nathan McNeil and Sirisha Kothuri
LinkedIn

Joe is a second year graduate student in the Master of Urban and Regional Planning (MURP) program at PSU focusing on active transportation and transit planning. During the summer of 2025 he supported Nathan McNeil and Sirisha Kothuri on a project for the District Department of Transportation in Washington D.C. evaluating the effectiveness of curb extensions in the city. In his free time, Joe enjoys running and exploring the PNW with his wife, Charlotte.


Jiahui Ma
Advisors: Jennifer Dill and Nathan McNeil
LinkedIn

Jiahui is a Ph.D. student in urban planning at the Nohad A. Toulan School of Urban Studies and Planning. She is currently supporting Jennifer Dill and Nathan McNeil on the Evaluation of Road User Comprehension and Compliance with Red Colored Transit Priority Lanes as well analyzing data from the Breaking Barriers to Bike Share project. 

Elijah Whitman-Powell 
Advisor: Tammy Lee

Xinhao ZhangXinhao Zhang 
Advisor: Tammy Lee 
LinkedIn

Xinhao Zhang is a Ph.D. student in the Computer Science Department at Portland State University. His research focuses on machine learning, reinforcement learning, and large language models. He specializes in algorithm design and data analysis, with previous experience in applying LLMs to analyze tabular data to enhance model performance.