News & Media

WILDLIFE: Pragmatic, cost-effective design wins crossing competition

by Laura Petersen (Land Letter)
January 27, 2011

A New York-based design team’s single-span bridge constructed of prefabricated concrete took top honors in the ARC International Wildlife Crossing Infrastructure Design Competition last weekend, beating out four other finalists to establish what could become a new standard for highway planners looking to incorporate wildlife needs into road projects.

The competition’s five-member jury unanimously selected the “hypar-nature” concept by HNTB Corp. and Michael Van Valkenburgh Associates Inc., crediting the design for being “cost-effective, modular, easy to construct,” providing “greater material control,” and using “a unique built-in drainage system.”
The $40,000 competition, sponsored by the Western Transportation Institute and the New York-based Woodcock Foundation, challenged participants to design a lighter, more sustainable and movable wildlife overpass for half the cost of today’s crossings, estimated at about $12 million apiece (Land Letter, Jan. 20).
A single-span design by New York-based HNTB Engineering and Michael Van Valkenburgh & Associates won last weekend’s ARC International Wildlife Crossing Competition. The team was credited for its innovative use of prefabricated concrete to create an easily adaptable and cost-effective crossing. Image courtesy of HNTB/Michael Van Valkenburgh & Associates.

“We always enjoy working on competitions because it gives us the venue to explore new and different ideas in a little bit more creative way,” said Robert Rock, a senior associate with Michael Van Valkenburgh Associates.

While maintaining its commitment to innovative design, the HNTB/Van Valkenburgh team also took a pragmatic approach to come up with a bridge concept that could be built using currently available materials and existing engineering standards, Rock said.

The result is a single-span bridge made of prefabricated concrete pieces that can be easily fastened together in a variety of widths to accommodate different wildlife and transportation needs. The design also does not require center support pillars, making it safer for motorists.

The team’s wildlife crossing, which was tailored for a site on Interstate 70 at West Vail Pass, Colo., is the width of a football field — twice as wide as the competition asked for — but could still be built for $7.5 million, Rock said.

“By making it something that really is scalable, adaptable and mobile, it doesn’t have to be crossing that cost $8 million to put in,” he said. “It’s a design that can be one-third the size and still function, and so it makes it a little more doable.”

Among other things, the jury recognized the HNTB/Van Valkenburgh team for its innovative use of concrete, a common construction material, and developing a bridge that can be installed without closing both sides of a highway.

According to experts, between 1 million and 2 million wildlife-vehicle collisions occur every year in the United States, resulting in more than $8 billion in accident-related costs. “When you look at the statistics and see it’s an $8 billion problem per year, it’s shocking to us it’s something that hasn’t been dealt with yet,” Rock said.

Wildlife biologist Tony Clevenger of the Western Transportation Institute at Montana State University proposed the competition as part of an effort to drive down costs associated with designing and building wildlife crossings. Experts hope that by developing on a more uniform, cost-effective design, more highway planners will incorporate wildlife crossings into road-building projects.

Thirty-six proposals were submitted to the ARC competition by teams representing more than 100 firms from nine countries.

“This competition demonstrates that we have the technical expertise and the know-how to overcome design challenges and implement cutting-edge survival practices,” Charles Waldheim, chairman of the ARC jury, said in a statement. “What we really need now is the political, economic, and social leadership to bring this design to life.”