Design Center mobile

Clinton Keith Road Extension - Phase II

Murrieta, California

Wildlife Overpass / Highway Underpass


CH2M Hill


Sukut Construction


April 2017

Technical Description:

• 60' x 22' x 109.63' BEBO® Bridge Concrete Arch System
• 66' x 24' x 109.63' BEBO® Bridge Concrete Arch System

The County of Riverside and the City of Murrieta first initiated a project in the mid 1990s to address the need for an additional east-west corridor by extending Clinton Keith Road from I-215 to State Route 79. Phase I consisted of widening the road between I-215 and Whitewood Road from two to six lanes and was completed in 2011. Phases II and IV extended the six-lane road an additional two miles from Whitewood Road to Leon Road. Completed in Fall 2018, it included two sets of traffic signals and two bridges, one of which was a wildlife crossing.

Originally envisioned as a safe crossing for the endangered Quino checkerspot butterfly, the structure also needed to provide passage for motorists on the road below. During the feasibility portion of the project, Riverside County along with various biologists and Universities, studied the area to determine the appropriate location for the wildlife crossing. Once the location was determined, the county turned to Contech Engineered Solutions for help due to their previous experience and knowledge designing these types of structures. 

Two BEBO® Bridge Concrete Arch Systems, 60' x 22' x 109.63' and 66' x 24' x 109.63' in size, were selected as the best option. CALTRAN design methodology was followed for the structural design of the structures. In addition, a traffic clearance diagram was created to accommodate three lanes of traffic, a bike lane and a sidewalk for pedestrians on both sides of the underpass. The BEBO structures were able to span the required roadway corridor with room to spare.

The precast arches were installed via crane in just three days. Lightweight fill on top of the structure, in conjunction with sub-grade geogrid reinforcement, was utilized to further reduce footing size, while also eliminating the need for deep pile foundations. By utilizing a buried bridge system such as the BEBO, the county was able to obtain a cost effective, long term, virtually maintenance free solution. Furthermore, due to the material and structure efficiency, this structure was significantly less expensive than material procurement, installation and future maintenance would have been for a different alternative.

"Contech was instrumental in the successful construction of the wildlife crossing," stated Steve Gonzalez, Project Manager with Sukut Construction. “Their ‘turnkey’ design and previous experience with wildlife crossings provided the necessary support for a smooth and successful installation. We are more than pleased with the final product and look forward to working with Contech on future projects.”

The new section of roadway is projected to carry 14,000 vehicles per day with a long-range projection of 35,000 per day. Once installed, the new structure protected not only the endangered butterfly, but also provided a safe, natural passage for deer, coyotes, mountain lions, foxes and rodents. Fencing was installed along the highway to convey wildlife to the structure, while also providing fall protection.

"Not everyday are we challenged with the elements that nature has to offer us in the design of a project," said Alicia Cannon, P.E., Project Engineer with CH2M Hill. "This project brought that unique facet into our decision making and ultimate design approach. With the help and expertise of Contech, they were able to provide a product that minimized disturbance to endangered wildlife."

The project was funded by the Riverside County Transportation Commission (RCTC) Measure A, TUMF SW Zone, SW Area RBBD, CFD, developer contributions, developer in-lieu funds, and the Eastern Municipal Water District (EMWD). Phase III, the final phase of the project, is currently in the design stage and tentatively set to begin in 2020. Upon completion, it will extend the road from Leon Road to SR-79 / Benton Road.

Technical Description:

• 60' x 22' x 109.63' BEBO® Bridge Concrete Arch System
• 66' x 24' x 109.63' BEBO® Bridge Concrete Arch System

800-338-1122 |


© 2023 Contech Engineered Solutions LLC, a QUIKRETE Company