Then another later noted that not every grade separation can be an elevated solution, and it would likely be a trench if located on a hill. He also said that an elevated solution should be considered wherever possible.
While I agree that a viaduct shouldn't necessarily be dismissed by overshadowing and ugliness if not in a particularly visually sensitive area, I don't entirely agree with elevated rail being better for connection and open space to the community.
Putting a railway underground can be very good for that in fact.
A railway cutting with lots of bridges over it can also be very good for connection and it is possible to build things above it, even roads and footpaths can go above an electrified railway, at least if not used by diesels.
In fact, I, on the whole lean towards road based grade separation, and this ought to be considered in flat areas where it's possible without building demolition.