Local street and road repairs are costly for any city and when the city of La Cañada Flintridge learned that one of its essential bridges rated below standard sufficiency rating in 2010, it needed to search for funding to develop a construction plan to replace the bridge. The bridge load was restricted to a maximum of 12 tons due to the lowered sufficiency rate. This prevented heavy vehicles such as fire trucks, trash trucks and utility vehicles from using the crossroad to provide timely services to residents in that particular area. The bridge replacement was essential to order to improve services.
The city of La Cañada Flintridge is in north Los Angeles County in the San Gabriel Mountains foothills. Located in the heart of the city is the Jessen Drive Bridge, built in 1940 and reconstructed in 1961. The original bridge was a timber “A” frame truss bridge with steel rod hangers and tension ties, a timber plank deck with an asphalt concrete overlay on timber stringers which was supported by steel pile abutments. It spanned 41 feet and was 27 feet wide with a 4 foot wide sidewalk and a 23 foot roadway, providing essential access to neighborhood homes, an elementary school and a primary thoroughfare for main city services.
The bridge was initially put on the 2000 Eligible Bridge List (EBL) of the Federal Highway Bridge Replacement and Rehabilitation Program (HBRRP), which is currently known as the Highway Bridge Program (HBP). In 2010, it received a sufficiency rating of 44.6, with a SR of 50 or less being eligible for replacement. The city knew that replacing the bridge would be costly and involve vast coordination with several agencies, but it was up for the challenge.
Since the project would be such a huge undertaking, it would be essential to coordinate with neighborhood residents, the nearby elementary school and the public safety. Additionally, since the bridge had been on the Caltrans deficient bridge list, there was limited time before the bridge continued to deteriorate to the point that further restrictions would have to be put in place, causing serious risk to the residents.
The Jessen Drive Bridge project would be an investment in the state and local infrastructure, support job growth and provide economic opportunities access to the other side of town would increase with the completion. Building effective partnerships between state and local officials, as well as other organizations to promote local authority to meet the community’s needs, would be integral to the process. The city experienced emergency evacuations and needed fire access during the Station Fire in 2009, and the mudslides following in 2010. While the city lost no structures and the access was adequate enough to use, the city determined at that time that it would apply for funding for the new bridge.
Protecting native plants, trees and the local wildlife habitat would also be crucial because the bridge is located in an environmentally sensitive area and stretches over a significant drainage canyon. Construction of the bridge would involve planning and rerouting several city services, as the delivery of six 70-foot long precast and pre-stressed reinforced concrete girders would need to be taken through narrow and winding streets. Additionally, overhead electrical lines would have to be de-energized to facilitate the massive crane necessary to set the girders in place. Some other challenges would be maintaining traffic circulation of the adjacent elementary school, relocating existing utilities (sewer, gas, water, and power), and maintaining access for the adjacent properties.
The city secured a $1.6 million Federal Highway Bridge Program grant and also contributed $200,000, combined these funds were enough to complete the project. After funding was in place, the city began working with many agencies to prepare for the construction of the project including Los Angeles County, the U. S. Army Corps of Engineers, the State Regional Water Quality Control Board, California Department of Fish and Game, and the Sheriff’s Department.
Several meetings were held to coordinate construction and traffic management plans for the duration of the project. The Public Works & Traffic Commission discussed the selection of the bridge barrier and railing and a community meeting was held prior to the commencement of the project to discuss the projects impacts on traffic flow. In addition, a city council meeting was held, as well as numerous meetings joining the various utility companies, local elementary school and school district. The public was very informed and involved throughout the project and provided valuable feedback.
Construction of the new Jessen Drive Bridge began in March of 2012 and opened to traffic in November of that year. All emergency and heavy public service vehicles now use the passageway without any restrictions, which allows them to provide better public safety and services to the area. School officials and parents were also pleased with the outcome of the project and shared their positive comments.
The city completed a desperately needed bridge replacement project, going from an insufficient rating to fully sufficient, with a minimal financial contribution and did the project in an environmentally-friendly way.
The new bridge has a reinforced concrete deck on pre-stressed concrete girders on reinforced concrete abutments and footings. The new bridge is 71 feet long and 40 feet wide with a 5-foot wide sidewalk and 32-foot wide roadway. The delivery of the six 70-foot long girders was taken through winding roads safely and without incident. New technologies in strength in the steel girder bridge, replacing the old wooden bridge, were definitely utilized for structural integrity.