Bridges have evolved a lot over the centuries. These five nextgen projects offer a look at where design is going.

Slauerhoffbrug (Leeuwarden, Netherlands)  This "flying drawbridge" was constructed to allow boats to pass. According to a profile in the NY Daily News:

The "flying drawbridge" ... raises a 50-foot-by-50-foot section of roadway high into the air ... The panel is painted in the blue and yellow, creating a bright symbol high in the air.

The bridge, one of several unique pieces of infrastructure the Dutch have conceived, was also featured in Popular Mechanics and on Core77.

FlexiArch Bridge  (Waterlooville, Hampshire, UK)  According to

Civil Engineers at Queen’s University Belfast have developed the world’s longest ‘flat pack’ arch bridge. Based on the ‘FlexiArch’ system, the bridge is unique in that it will be transported to site in flat-pack form but when lifted, will transform under gravity into an arch ... A FlexiArch bridge requires little maintenance and should last 300 years, compared to the projected lifespan of up to 120 years that accompanies a conventional bridge. It is the result of 10 years of research from the early 1990s ...

This will be the largest installation of the technology, now in use in more than 50 bridges throughout the UK and Ireland.

Confluence (San Francisco-Palo Alto, Calif.)  Confluence, is the winning design in an international competition to design the Bay Area's Adobe Creek Pedestrian/Bicycle Overcrossing Project. According to dezeen:

[Confluence] is a weathered steel structure that spirals gently up from the ground and is supported by a series of cables extending down from an arch that spans the width of the 14-lane 101 freeway.

Proposed by 64North Architecture, HNTB Engineering, Bionic Landscape Architecture, and artist Ned Kahn, it is described by the architects as "the first curved network cable arch of its kind".

"Earthquake Proof" precast concrete bridge (University of Nevada)  Concrete Engineers at the University of Nevada, Reno have successfully tested a precast concrete bridge that withstands massive shaking. The bridge was tested at the world-renowned Earthquake Engineering Laboratory, and according to a University press release:

The 50-ton, 70-foot-long higher seismic-performing bridge, designed of pre-cast concrete columns and beams, was pre-cast and then built atop three 14- by 14-foot, 50-ton-capacity hydraulically driven shake tables. It was shaken Feb. 6 in a simulated earthquake, mimicking the large ground motions of the deadly and damaging 1994 Northridge, Calif. earthquake. Researchers used 230 sensors and gauges to monitor the stresses on the bridge and its components.
"It had an incredible 9 percent drift with little or no damage," [Saiid Saiidi, civil engineering professor, said]. "I'm excited to see the results and pleased with how well the bridge performed under extreme conditions. We subjected this bridge to a series of earthquakes, took it apart, and reassembled it before the final experiment. There's a lot of data analysis ahead of us, but the initial result shows success."

Sarajevo Bridge (Barcelona Spain)  BCQ architects has unveiled plans to give a major green facelift to Barcelona's Sarajevo Bridge. According to Inhabitat:

... designs will bring a dramatic change to the Sarajevo Bridge—currently a boring and unsheltered roadway devoid of greenery—and clad the structure with green walls and pergolas. The bridge’s pavement will be replaced with photocatalytic concrete, a self-cleaning material that oxidizes pollutants and purifies the air. To make the bridge energy self-sufficient, the structure will be lit by solar-powered LEDs and photo-luminescent elements embedded into the concrete.