Environmental - FlyRails

Eco-friendly small non-polluting solar-powered vehicles.
No soil erosion. Little impact on plant and animal life.
Walk to nearby station.
Tiny footprint with with small poles.

Environmental - Monorails

Uses massive amounts of concrete a major contributor to global warming.
Requires polluting ground traffic.
Huge impact on neighborhood during construction.
Adversely affects plant and animal life.

Environmental - Ground

Vehicles are extremely polluting.
Massive concrete generates greenhouse gas.
High impact, huge footprint and soil erosion.
Kills plants and animals.
1/3 of a city's land is used for roads and parking.