Survival Mode in Fallout 4 is being revamped, according to a Bethesda tweet. A subsequent post on Bethesda's website details all of the changes that will be implemented for players on the Survival difficulty.
As of 03/29/16, this update is available as beta on Steam.
One of the features for this updated Survival Mode, per the Bethesda post, states that fast traveling is disabled. However, there is at least one location that seem to only be accessible by fast traveling.
The Institute, after they install the relay into your Pip-Boy as part of the Institutionalized quest.
How do you visit locations that are only accessible by fast traveling while playing in the updated Survival Mode?