Texas Trees Foundation directed a study for redesign of a corridor to improve pedestrian health in  the Southwestern Medical District in Dallas, Texas. The streetscape intervention which considered modifications to traffic flow and a massive tree planting initiative. The Hyphae Design Laboratory was selected to integrate the design and intervention process within the evidence-based design framework to monitor health-improving interventions, including setting up the area as a living laboratory for sustainable design. 

We conducted simulations on thermal comfort across the whole corridor using a model of the existing conditions. We then simulated many iterative intervention scenarios in a representative section of the corridor, and several designs for the park at Innwood to test various design rubrics for efficacy. The results of these iterations produced several key findings:

• The replacement of large mature trees with younger trees will increase heat stress on pedestrians. 
• Sparse plantings will be less effective than larger groups of shade trees, which work together synergistically to produce not only more shade but also pockets of cooler air that can cool downwind areas that are not in the shade. 
• Groves of trees with large trees around the edges and larger open space can result in cooler open spaces than smaller open spaces with a larger number of smaller trees
• In some areas where wind speed is high due to the presence of building corners, planting shade trees actually makes it hotter, when the benefits of shade are outweighed by the benefits of high wind. 

The Southwestern Medical District’s Green Spine Streetscape and Park intervention has the potential to become a national model of evidence-based design, revealing how targeted landscape strategies can improve both environmental conditions and public health. Through a rigorous process of data-gathering, simulation, and on-site monitoring, this project has already demonstrated how carefully placed large-canopy trees, vegetated buffers, and strategic landscape configurations can substantially reduce thermal stress while potentially mitigating traffic-related air pollution. Early findings underscore the outsized influence of mature canopy trees on lowering mean radiant temperature, the importance of thoughtful species selection for air quality and biodiversity benefits, and the potential of carefully placed vegetation in improving pedestrian and cyclist thermal comfort.  When integrated into a cohesive framework for collaboration by connecting local stakeholders, designers, engineers, planners, and researchers, these insights can guide decision-making at every stage of design and implementation.