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When we improve infrastructure, we also have an opportunity to enhance communities and protect the environment. The Clinton Keith Road Extension Project in Murrieta, California, is a prime example. 

�������� led the planning, design and construction of a six-lane urban arterial highway extension that integrates bike lanes, sidewalks and— notably—California’s first wildlife overpass. This groundbreaking feature enhances habitat connectivity and road safety along a three-mile stretch in Riverside County.

Protecting wildlife and travelers

A wildlife crossing is a purposefully designed structure that allows animals to move safely across busy roads, reducing the risk of wildlife-vehicle collisions and preserving local ecosystems, explains �������� Senior Transportation Ecologist Shannon Crossen.

“Wildlife overpasses are typically covered with natural vegetation to blend with the surrounding habitat and encourage use. By providing safe passage, these crossings protect native species while improving safety for the travelers.”

To address the need for an additional east-west corridor to accommodate increasing traffic demands, the County of Riverside Transportation Department (CRTD) engaged �������� to deliver the project from preliminary design and environmental approvals through design and into construction. 

�������� incorporated multiple wildlife connectivity features into the roadway’s design to align with the River County . Along with the iconic overpass, the project includes multiple wildlife underpasses, such as:

• A three-span bridge over Warm Springs Creek
• A single span bridge over French Valley Creek
• A double arch natural bottom culvert 
• Additional culverts with dry ledges and skylights for safe wildlife movement 
• Custom-designed wildlife fencing to guide species and provide escape routes

Recognized for excellence

The project has earned major industry recognition, including:

• The American Public Works Association (APWA) Large Project of the Year award, highlighting collaboration between CRTD, �������� and other project partners. 
• A California Department of Transportation (Caltrans) Excellence in Transportation Award for outstanding contributions to transportation infrastructure and conservation.

Project Manager Alicia Cannon emphasizes ��������' commitment to delivering innovative and cost-effective solutions, that keep nature and safety at the forefront, at every phase of the project lifecycle. 

"From planning and permitting, to design, construction and operation, we prioritize innovative solutions that protect wildlife and their habitats for future generations while improving mobility," she says. "California’s first wildlife overpass demonstrates how we can meet critical infrastructure needs without compromising environmental preservation."

A model for future infrastructure

The Clinton Keith Road Extension Project significantly improves the quality of life for local communities by reducing congestion, shortening travel times and expanding access to jobs and education—especially for disadvantaged populations. 

�������� continues to lead nature-positive infrastructure project nationwide. In 2024, we supported grant applications for the Federal Highway Administration’s Wildlife Crossings Pilot Program and led studies for Caltrans District 5 to reduce wildlife-vehicle collisions along US 101. �������� also played a key role in feasibility studies for multiple crossings in Montana, a specialized overpass on I-25 in Colorado and Washington State’s Snoqualmie Pass East Project—one of the largest ecological connectivity projects in the country.  

By integrating nature-positive solutions into transportation planning, �������� is helping to shape a safe, more sustainable future for both people and nature.