Dr. Humphreys specializes in the application of optimal detection and estimation techniques to problems in satellite navigation, autonomous systems, and signal processing. He directs the Wireless Networking and Communications Group (WNCG) and the Radionavigation Laboratory.

Humphreys is also on the graduate study committee of UT Austin's Department of Electrical and Computer Engineering. He received the UT Regents' Outstanding Teaching Award in 2012, the NSF Career Award in 2015, the Institute of Navigation Thurlow Award in 2015, the Presidential Early Career Award for Scientists and Engineers (PECASE, via National Science Foundation) in 2019, the IEEE Walter Fried Best Paper Award in 2012, 2020 and 2023, the Institute of Navigation Kepler Award in 2023, and the Royal Institute of Navigation's Harold Spencer Jones Gold Medal in 2025. He is a Fellow of the Institute of Navigation and of the Royal Institute of Navigation. Humphreys joined the faculty of the Cockrell School of Engineering in Fall 2009.