Much of the cost and complexity of traditional road and rail projects originates during the land acquisition phase. New rights of way need to be secured, environmental studies need to be commissioned, and existing utility structures need to be moved and re-engineered.
In contrast, the efficient, elevated design of monorail often allows it to fit into existing rights of way. This saves cost, time, environmental damage and risk - not to mention land.
A monorail beam is only 27.5" wide and sits atop 36 square foot columns, typically 6' square, which are spaced from 80'-120' feet apart.
Compared to the impervious surface created by roads, BRT, light rail, or heavy rail, the environmental footprint of monorail is negligible.