I-5/La Novia Roundabout
Location
La Novia Avenue and Valle Road
City or County Responsible for Project
San Juan Capistrano
Category
Complete Streets Projects
Author
George Alvarez
City of San Juan Capistrano
32400 Paseo Adelanto, San Juan Capistrano, CA 92675
949-493-1171
Project Description
For nearly 20 years, the awkward, offset I-5 freeway off-ramp intersection in the City of San Juan Capistrano was the subject of many alternative improvement concepts. The existing stop-sign-controlled intersection was regularly congested, and the complicated geometric design created confusion among commuters, leading to higher than normal traffic incidents. The City’s $2.2 million I-5/La Novia Roundabout project improved the traffic pattern and flow through the re-alignment of the northbound I-5 exit and entrance ramps, Valle Road and La Novia Avenue with a sustainable and modern roundabout design. This is the first roundabout on the state highway system in Orange County, California, and the first to have been formally analyzed and approved through Caltrans’ Intersection Control Evaluation (ICE) process in District 12. Utilization of the performance-based ICE process created a transparent approach for agencies to look beyond conventional intersection designs to find an alternative that best accomplishes the City’s safety, operational, cost and environmental goals. The roundabout was designed to address both existing and projected operational deficiencies by improving traffic direction, easing congestion and accommodating future local and regional growth. The design of the four-legged roundabout included an inscribed circle diameter of 150 feet, a landscaped central island, a traversable truck apron, single lane approaches and raised splitter islands. The project has resulted in improvements to safety, air quality and community aesthetics. Roundabout intersection design has a documented history of reducing the severity of collisions by lowering speeds at intersection approaches and in the intersection itself. The number of vehicle-to-pedestrian conflicts at the La Novia intersection reduced from 24 points, with a signalized intersection, to 8 points with the modern roundabout; a 67 percent total reduction. The project was designed to fit the existing topography, which was constrained by a steep hillside landform to the east of the I-5 and the close proximity of Valle Road to the I-5, which made for a very tight work area in which to improve the intersection. An eight-stage construction staging/traffic handling plan was developed to address the complexities of the work sequence while keeping the intersection open to traffic. The plan and execution by the contractor were so successful that the intersection operated more efficiently during construction than prior to construction. The public engagement efforts were also an integral part of the project and helped to overcome initial concerns to gain and maintain the invaluable trust of the public. Upon project completion, the FHWA profiled the I-5/La Novia Roundabout project on an informational poster used to communicate the benefits of roundabout intersections nationally. The guidance was prepared to assist with the implementation of intersection safety improvements across the country.
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