A Modesto, California study found that asphalt on streets shaded by large canopy trees lasts longer than asphalt on unshaded streets, reducing maintenance costs by 60% over 30 years.
McPherson, E. Gregory, and Jules Muchnick. Effects of Street Tree Shade on Asphalt Concrete Pavement Performance. Journal of Arboriculture 31, no. 6 (2005): 303-310.