Glenn is a research professor at the Institute for Urban Research whose work focuses on transportation infrastructure, community development, and environmental justice. His environmental justice work has been included in the initial version of the FHWA EJ Effective Practices Guidebook, Environmental Justice community engagement model and asset mapping components are included in the NCHRP Report 710, Practical Approaches for Involving Traditionally Underserved Populations in Transportation Decision-Making, as examples of effective practice, and its performance measures are used in TCRP Report 150, Communication with Vulnerable Populations: A Transportation and Emergency Management Toolkit.

The content of his work was highlighted in the Environmental Justice and Transportation track for the State of America Environmental Justice Conference proceedings; was infused into the Chicago Metropolitan Area Plan (CMAP) Sustainable Community Initiative (SCI), and influenced the operation of the TRB Environmental Justice and Transportation Committee from 2006 - 2012. Additionally, his EJ work inspired articles published in the Journal of Transport and Land Use and Transportation Research Part A.