In remote areas, where trafic is not much, usually govenments don't build bridges because they can not justify spending.
In such low trafic areas, one can use zipline/cable car to transport people; This has been done long time back. However cable way should also transport empty cars, two-wheelers, minivans etc. Most of the cable ways can easily take up weight upto one ton.
So people can drive upto cable car; transport themselves in a cable car. Transport the empty car saperately by hanging it to cable. Once reached other side, continue journey in the car.
This could be a lot cheaper than building a bridge.-- VJW, Jun 13 2011 Something like this, but with modification. http://www.youtube....watch?v=PLH00zaqs_sLooks cheap enough... [VJW, Jun 18 2011] This is called a transporter bridge, and they exist but are not common. I suspect the cost isn't that much lower (since you still need the cable support structure and machinery) for a huge reduction in efficiency.-- MechE, Jun 13 2011 Cableways can be installed in day and transported elsewhere as required. .i.e. they can be temperorily installed. Transporter bridges seem to use much heavier structures, like rails on which cart moves. Cableway, which need just one cable are comparitively lean-and-mean setups.-- VJW, Jun 13 2011 Cableways that are capable of carring even a single car are not temporarily installed. At a bare minimum you're going to need two gantries with a high load capacity, both also tall enough that cable sag doesn't hit the water; extensive anchoring; and a motor that is capable of pulling the car back up from the low point of the sag.
That bare minimum set-up will not work in even moderate winds and will have zero redundancy in case of failure (two cables is kind of the minimum).
There is no conceptual difference between this and a transporter bridge, it's just that the transporter bridge is built to a practical scale and safety level.-- MechE, Jun 13 2011 I'm imagining a ski lift combined with the electromagnets they use with car crushers. A continuously moving cable loop with spaced electromagnets that snap onto the roofs of cars and haul them and the passengers to the other side. You might lose a car or two in the gorge when they have luggage on the roof, but people would quickly learn.-- ldischler, Jun 18 2011 ldischler, - yes, exactly.-- VJW, Jun 18 2011 How much maintenance, for even minimal safety? With that, would it really be cheaper than a bridge?-- mouseposture, Jun 18 2011 One advantage with cableway is that it can have a steep incline. Bridge, can't.
Are ski-lilfts that high mentainence ?-- VJW, Jun 18 2011 Well, if skiers weighed as much as automobiles they might be. And ski-lifts *do* require regular maintenance for safety. You wouldn't leave a ski lift running for long unattended, for example, while you can certainly do that with a bridge, inspecting ... what, annually? Biannually? Repaving and repainting what ... biennially? But good point.-- mouseposture, Jun 18 2011 It seems crazy for people heading north to haul their vehicle over the chasm, while other people heading south haul their vehicle the opposite way. Just provide hardstanding for people to leave their car parked on, for flks disembarking in the opposite direction to drive off in. Legally enforcible notices, with lump hammers and hotwiring kits attached, announce that any car parked nearby is available for use by cablecar travellers.-- pocmloc, Jun 18 2011 random, halfbakery