The negative impact of trees on the performance of lighting systems is widely assumed but not particularly quantified. The positive impact of trees with their social, economic, environmental, and experiential benefits is also well known and one of the staples in context-sensitive solutions for transportation projects. This paper looks at the issue of trees and lighting and tries to quantify the possible impacts and to develop tools for planners, administrators, road authorities, and the professionals who design, install, and maintain trees, landscaping, and lighting equipment. Because of conditions at the test site, a focus on the pedestrian environment was chosen for this study, although the results generally apply to the roadway environment. The subject is complex and not simply addressed so this initial work focuses on identifying whether there is really an issue, what variables to consider, and what course to recommend for future investigation.