Building Safer Roads in a Region on the Move

Under a busy road in northern New York, TNC and the New York State Department of Transportation installed a simple, inexpensive fix: a steel mesh “critter shelf” in a culvert to give mink, groundhogs, raccoons, weasels and other small animals their own corridor so they can travel and move while avoiding cars.

Developed in Montana and adapted for New York, the shelf demonstrates how good ideas can travel. Stephanie Delano, director of the Environmental Science Bureau at the New York State Department of Transportation, says, “We learned about the work in the West, worked with The Nature Conservancy to adapt the design and build a shelf here, and we’re proud this project is featured in the Habitats and Highways series, reaching our peers who can replicate similar solutions in their states.”

A small investment—$10,000 within an $8 million project—helped Vermont’s Fish and Wildlife Department and Agency of Transportation build the state’s first wildlife shelf under a bridge along the Little River. “This dirt path allows moose, deer and other animals to move under the bridge instead of on the road,” says Hawkins-Hilke. “It was so successful that it is now our standard procedure to put similar structures under any bridge project with enough room for a corridor.”

Vermont isn’t the only state establishing transportation policies to help wildlife: New Jersey passed the Wildlife Corridor Bill, which appropriates funding to assess how proposed roads impact wildlife, including endangered bobcats. It also directs agencies to collaboratively identify key corridors and collision hot spots, prioritize crossing projects and improve safety for both motorists and wildlife.

When planners at the Maine Department of Transportation designed six miles of new road, they treated it as a chance to reduce collisions, mitigate flooding and keep habitat connected. Wildlife fencing now guides animals away from traffic and toward culverts that carry water during storms and give fish and aquatic animals an easy way through.

In Connecticut, planning for a new road in Brookfield, led by the Connecticut Department of Transportation (CDOT), began with wildlife assessments. As the project was designed, CTDOT added concrete barriers that usher wildlife toward a tunnel under the road. Cameras showed deer, skunks and other mammals using it immediately, and radio-tracked turtles soon followed.

In New Hampshire, modeling showed TNC scientists that a protected section of coastal marsh critical for birds, including the vulnerable saltmarsh sparrow, would be overtaken by sea-level rise in the coming decades. Storm flooding was also making an upland road unsafe for drivers. Together, TNC and the local public works department replaced an undersized culvert that blocked migratory fish and contributed to flooding. The new design also creates room for the marsh to move inland as sea levels rise, allowing the habitat itself to migrate rather than drown.

Now, more water moves under the road during extreme rain, the marsh can shift naturally, and wildlife from fish and eels to deer, otters and bobcats use the crossing and stay clear of traffic.

Across the region, agencies are confronting similar challenges. In Massachusetts, the state’s transportation and fish and wildlife agencies redesigned a site planned for mixed development and a new parkway to better support wildlife movement. The project added three wildlife crossings and a stream crossing to keep species connected, with fencing and wing walls guiding animals safely toward those crossings.