The idea of gravity-assisted ropeway is old in Europe. In the mountain regions of Northeast India and Northern India where construction of roads is difficult and environmentally unsustainable, ropeways can play an important part. One kilometer of road demands 4 hectares of forests to be cleared. The cost of construction of a rural road is about Rupees 2 crore per kilometer of length. Then rains cause damage rendering maintenance an expensive affair. To travel between two hills, from one village to another, it may take a few hours. In most of the remote mountain regions there are no roads for vehicles.
Between two hills, one lower and the other higher a ropeway can be installed to transport both cargo and passenger. Gravity-assisted ropeways operate utilizing the gravitational force. They are simple and inexpensive. They only demand local expertise to maintain and repair. Some of the farming communities are successfully using such ropeways in Chittagong Hill Tracts region of Bangladesh, Nepal and Uttarakhand of India.
The ropeway system consists of two towers located at two different heights. Two trolley-carriages roll over a single-looped steel wire rope suspended from the towers around pulleys. When the carriage-trolley at the upper point slides down with heavier load it hauls up the carriage-trolley with lighter load from the lower point. A heavy flywheel of steel controls the speed of the sliding carriage-trolleys besides helping the operator to bring them to a halt. It is energy-efficient and environmentally-friendly.
I like your idea and can be implemented. It is energy efficient too. But the initial investment would be a bit higher, but it would anyway be less than that of laying a road. The problem is with the load carrying capacity of the trolley, the only advantage of the road being it's load carrying capacity and the flexibility it offers. But this sure is a nice idea and can be implemented for uses other than the heavy luggage movement. I admire you idea, but an estimate on the costs to layout would make it more viable. A brilliant idea.