Since its beginnings, it has been difficult to access Gruyeres due to the sole route and its steep gradient.  
" In Gruyeres, it is climbing everywhere "

Before you arrive in Gruyeres you have to leave your car in a parking along the steep road. Indeed no vehicles, except the "Petit Train", are allowed inside the old pedestrian city of Gruyeres.

The "Petit Train" saves you a steep and tiring walk (up to 0,9 mile) while allowing you to discover and enjoy the scenic landscape of the valley. You will then arrive comfortably and full of energy in the hearth of Gruyeres, this medieval jewel, with its Castle, its old ramparts, its shops and restaurant, the Giger Museum, ...

More details :

Copied from  a personal web site found (feb 17th 2004) on the Internet :
" An innovation since our last visit -- A TRAIN so you don't have to walk all about to see the sights! Splendid! The village is only one street about 150 meters long, but this cool train will save you the effort of walking back and forth along it AND take you down to, and back up again from, the cheese factory/museum in Pringy at the bottom of the hill. "
More details: See later our link's page -references-  "Mr Dwight Peck (personal web site) "