Although the solution might be whimsical, the problem is quite realistic.
To get a sight where you are going might be easier by:
- TV in carriages and a (panning) camera in front of the train,
- maybe just broadcast it over WIFI as many passengers have smartphones, tablets etc.
- replace the windows with LCD’s and give the traveller a menu to select scenery. You could virtual drive through Toscane while actual in the suburbs of bigciry.

Cheaper solutions:
- add mirror’s by the dozen near the windows to get a front/backview (adjustable with joystick!)
- periscopes to get a 360 degree view (premium price seats)
- fisheye lenses in the ceiling providing daylight and a 360 view
- carriage from glass (90%)

Fun!