World's Last Rope Bridge

Via Boingboing.

When conquistadors arrived from Spain they were shocked. Spanning vast canyons, and longer than any existing European or Roman bridge was a type of bridge which they had never seen before: an Incan suspension bridge. Today only one example remains.

Made of woven grass, the bridge spans 118 feet, and hangs 220 feet above the canyon's rushing river. The Incan women braid small thin ropes which are then braided again by the men into large support cables, much like a modern steel suspension bridge. Handwoven bridges lasted as long as 500 years and were held in very high regard by the Inca. The punishment for tampering with one was death.

Over time, however, the bridges decayed, or were removed, leaving this single testament to Incan bridge engineering. This previously sagging bridge is now repaired each year, and christened with a traditional Incan ceremonial bridge blessing. The bridge is in extremely good condition and is a perfect location for all of us wishing to indulge in long harbored Indiana Jones fantasies.

How We Get Around

Via Infrastructurist. Pictures of different highway interchanges.

The Cloverleaf - a classic, but it has fallen into some disfavor among traffic engineers because it causes weaving because cars are entering and exiting in the same lane. It also doesn’t handle large traffic volumes as well as some other configurations (for example, stacks).

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The Stack - A vertically layered arrangement of highways and connecting elevated ramps. The number of levels varies and go as high as six (though three and four are more common). Stacks are expensive to build but very efficient for high traffic volumes. This example is in Shanghai, but there are many stacked interchanges in the US:

The Braid - This Maryland interchange is a stack design, but what’s unique about it is that the north and southbound segments of I-95 and east- and westbound segments of I-695 are actually braided over each other briefly in the middle of the interchange. (See a diagram here.)

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