Here is a striking example of a street that has a full tree-covered canopy, keeping the bitumen in perpetual shade. Thus, the temperature for the residents must be lower in summer, day and night, plus a large number of other environmental benefits. This effect can be replicated using pergolas stretching across all bare overhead sections of streets, roads, and highways. The acreage of roads in cities is enormous, and by greening them in this manner would be a substantial improvement to their liveability-quotient, in addition to many eco-diversity benefits accruing.