Simulating Impacts of Curbside Street Trees on Driver Performance and Perception

This research describes a pilot investigation of driving and trees in the clinically controlled environment of virtual simulation. Although they are considered undesirable by most pavement, utility and traffic engineers, the street tree may give the public and surrounding communities a sense of place and beauty and safety. The battle line drawn by the curbside tree issue is examined in this study, hoping to establish the methodological basis for a larger more comprehensive research project on the effects of the contextual roadside landscape on driving performance. The hypothesis of the pilot is to establish some proof that the curbside tree does provide a sense of place and improve perception of safety resulting in decreases in driving speeds and improved driver performance. We tested these questions by creating identical street pairs in real-time interactive virtual driving environments, one world with trees and the other without. We used both a suburban/rural city form and an urban city form. The results indicate that the street-tree lined streets created in the virtual environment are perceived as more safe, increase perception of place definition and, in the case of the suburban/rural landscape might be driven at slower speeds. Proof of concept regarding the methodology and the potential impact on safety and efficient trade-off resolution warrants further research.