During construction and operation, monorail generates far fewer disturbances compared to the alternatives. Its footprint is a mere 36 square feet for every 100 ft of elevated track reducing ground disturbance during and after construction. It accordingly has a minimal storm water footprint, and the long spans create space for hiking/biking trails, as well as maintaining large corridors for wildlife to roam beneath. The slim, concrete guide rails create minimal shadows, while the electric motors and rubber tires combine for a smooth, quiet ride.
Monorail also has the lowest carbon footprint of any form of mass transit. See the diagram below (BYD) to understand the dramatically lower CO2 emissions per passenger per kilometer offered by monorail.