Street trees provide a natural border to street space, create shade for pedestrians, decrease traffic speed by creating a visual friction that results in more cautious driving, and increase property values. Ecologically, street trees reduce heat island effects and filter airborne particles and groundwater pollutants. In urban locations, shade streets should provide complete street cover, with different streets using a different species of trees in a strategic effort to prevent blight through biodiversity. Trees should be in planters and equally spaced along the curb.
In less urban locations, trees should be planted in a grassy strip between the street and sidewalk, spaced further to let the trees grow to their fullest potential. Along rural roads, trees may be planted in more natural arrangements, with clusters of a range of tree species in various distances from the road.