Environmental engineering success is achieved through an integrated design process.
Laguna Canyon Road (SR 133), Orange County, Calif.
A full year of documented success has now become a part of the history of Laguna Canyon Road, California State Route 133 (SR 133). Originally a Native American trail and later a stagecoach passageway, this route was subsequently paved by the California Department of Transportation (Caltrans) to provide access to the coast. This American landmark is now considered one of our nation’s most environmentally designed roadways. The ribbon cutting ceremony, signifying 20 years of true collaboration, occurred in the fall of 2006 as the integrated approach to the design of Laguna Canyon Road culminated with the endorsement of biologists, public agencies, engineers, planners, architects, citizens, and public officials.
Fifteen years ago, both hand-painted and custom-printed signs of vehement opposition were posted at every corner, and the people, public officials, and agencies would have given Laguna Canyon Road at best a 10-percent chance of success for improvement. The world-renowned artist colony of Laguna Beach posted special holiday artwork, in place of its traditional palettes, on every light post throughout the town, expressing concern over any potential damage to Laguna Canyon. However, a few good engineers and transportation planners; a few solution-oriented citizens; and a few concerned Caltrans, city, and county representatives began a collaborative effort that not only changed the course of Laguna Canyon Road, but also expanded their thinking relative to a more sustainable approach to transportation design forever.
Challenges and solutions
The existing, winding two-lane country road was originally aligned in the bottom of Laguna Canyon, framed by rolling hills and rugged rock outcroppings vegetated with oaks, sycamores, and coastal sage scrub, comprising sensitive habitat for the region. Through the years, the rural roadway was challenged with demands for increased coastal access and development traffic created by a growing Orange County population. Also, since the roadway was originally aligned within the 100-year flood plain, it was subject to frequent closures caused by flooding, partially because the roadway bisected one of the canyon’s natural lakes.
To engineers, the solutions to the problems of the existing roadway alignment were obvious. The engineering goals were to widen the roadway to provide more lanes and increase traffic capacity; straighten the curved alignment to improve the design speed and safety; elevate the roadway above the 100-year flood plain to reduce frequent flooding, and provide a median area to separate opposite directions of travel and improve safety. Although these engineering solutions addressed the documented challenges of the existing roadway, they would have resulted in many impacts to the environmental setting, which were unacceptable to the community and resource agencies.
A widened four-lane roadway along the existing alignment would have eliminated the rural character of the existing road and restricted wildlife movement. Straightening the roadway alignment in the base of the canyon would have resulted in grading impacts to the natural canyon slopes. Elevating the roadway would have increased the footprint with resultant impacts to wetlands and native vegetation. The conflicts of the engineering solutions and environmental impacts appeared impossible to resolve. Regardless of the challenges, however, too many people cared too much about the roadway and the canyon to let the project come to a standstill. New, more sustainable solutions were sought with an integrated team approach.
A Citizens’ Oversight Committee was established comprising politicians, planners, environmentalists, and local residents to work with the engineering team. The initial engineering proposal was critiqued and the Oversight Committee made recommendations. The engineering team listened to the community, took their planning concepts, and refined them to reflect Caltrans’ design standards. An interactive process with the Citizens’ Oversight Committee transpired during the course of a year. The willingness of each party involved to listen to new ideas and appreciate the concerns and priorities of stakeholders resulted in a project that employed true environmental engineering and sustainable elements that were not even considered at the project onset.
After considering many alternative alignments, the engineering team formulated a design that addressed both engineering concerns and environmental issues. The new alignment relocated Laguna Canyon Road from the bottom of the canyon to the adjacent, less environmentally sensitive hillside areas. The engineering team carefully designed grading for the slopes so that the roadway naturally blended with the existing terrain. This elevation eliminated the issues of flooding with the help of a new drainage system of stormwater basins that effectively retain and treat roadway stormwater runoff. In addition to ending the flooding, the project included bio-swales to treat roadway runoff containing pollutants, significantly improving water quality and preventing future damage to nearby vegetation and wildlife or to downstream watercourses.
While ultimately widening Laguna Canyon Road to a four-lane state highway, the final realignment not only preserved the environment, but also maintained the aesthetic feeling of a two-lane roadway. This was accomplished through a wide, naturally vegetated and variable-width median between opposing traffic lanes. In addition to keeping Laguna Canyon Road’s character in tact and providing a wildlife refuge, the median acts as a safeguard against accidents. This was important because many previously documented accidents on SR 133 involved vehicles moving in opposite directions. Additional safety features included pullout areas for maintenance vehicles and acceleration and deceleration lanes at roadway intersections. The team expanded the outside paved shoulders of the roadway to 8 feet for the use of bicyclists who ride along Laguna Canyon’s Class III bicycle route.
In addition to carefully preserving current environmental resources, the design team worked to restore the natural environment that the original road had interrupted. The new alignment restored the originally bisected lake, and additional wetlands were created. To permit natural, safe movement of animals from one side of the road to the other, the design also included four wildlife under-crossings at key locations beneath the roadway.
Four wildlife under-crossings encourage safe animal crossings of the highway.
Rubberized asphalt was used for the top layer of roadway surfacing, which reduces noise from car tires and the pavement surface. Best management practices were used to prevent pollution from stormwater runoff both during construction and for the future of the roadway. Erosion control measures were key in reducing impacts to the adjacent sensitive watercourses and lakes.
The new roadway alignment also passes through an area previously inhabited by Native Americans. Archeologists mapped the area to confirm the locations of Native American resources and historical sites in order to respect the environmental, cultural, and legal boundary constraints.
"Careful consideration was given to the historical and ecological value of one of the few remaining coastal canyons in Southern California," said Ignacio G. Ochoa, assistant director of public works/chief engineer, Orange County. "By committing not only to public safety, but to nature … we have achieved a rare balance between preservation and progression."
To prevent impacts to the environment, construction was extended to a four-year schedule, avoiding California Gnat Catcher breeding and nesting seasons and reducing construction impacts on downstream water quality by avoiding major grading during the raining season, along with several other time-sensitive issues. The ability to incorporate these environmentally sensitive design features was a key factor in the success of the project, which dovetailed with the community contribution and agency input.
Critical to the project’s success was the Citizens’ Oversight Committee, formed as a part of the planning process. The engineers relied on this committee to provide valuable input from the perspective of the affected community. The committee consisted of Laguna Beach residents with interests, perspectives, and technical backgrounds ranging from biology to politics. This advisory group held monthly meetings in a workshop setting, brainstorming to identify and resolve their issues with the project. For example, when the team’s designers proposed an alignment to preserve a row of eucalyptus trees, the committee biologist pointed out that the trees were not actually indigenous to the area. With the committee’s approval, the team modified the alignment to eliminate the row of eucalyptus trees to preserve and restore natural habitat, and incorporated replacement planting of native oaks and sycamores as part of the project.
Jack Camp, a 30-year resident of Laguna Beach and president of an urban design company, played an important role in the Citizens’ Oversight Committee. His experience with project planning and his personal relationship with the Laguna Beach community gave him a unique understanding of both points of view. "After all the work that the city of Laguna Beach has done to preserve the Greenbelt … to have a road go through it is a big deal," Camp said. He acknowledged the great sensitivity with which the transportation planning and engineering team approached the project, and was pleased that the two-lane, open-air character of the road remained, even after the roadway improvements were completed. Camp noted the striking vistas of the lakes—Orange County’s only natural lakes—which the original roadway’s position at the bottom of the canyon concealed from view.
Experts on the Laguna Canyon Road Project Team included biologists and wildlife specialists, transportation planners, civil engineers (specializing in flood control and water quality, highway design, and traffic operations), archaeologists, citizens, officials from Laguna Beach and surrounding cities, highway safety authorities, recreational planners, and environmental planners. Team members worked in a collaborative atmosphere, with a goal of understanding each other’s perspectives on the project. The result was an outstanding success founded in respect and compromise. According to Orange County Supervisor Thomas W. Wilson, "This is a true testament to the strong partnership among the county, cities, Orange County Transportation Authority, Caltrans, and the environmental community. This is definitely a victory for all involved."
Today, more than 36,000 vehicles travel the new roadway daily. Approximately four miles have been rerouted for better design and environmental reasons, traffic congestion has been virtually eliminated, and the safety rating has improved. The SR 133 project, which cost about $32 million, is one of Orange County’s finest examples of what a collaborative effort between the engineering world, the environmental world, and the community can accomplish together. It has been honored with local and national awards and, in October 2007, the American Road and Transportation Builders gave its Globe Award to the project.
At the core of every transportation project is the goal of improving our transportation systems to their full potential. A commitment to accomplishing this goal, while also respecting the concerns of the community and the environment, can take us to a new, more sustainable level of success.
Gary Warkentin, is a transportation planner and vice president for RBF Consulting. Barbara Eljenholm, AICP, REA, LEED AP, is senior vice president of RBF Consulting. They can be contacted at firstname.lastname@example.org and email@example.com, respectively.