NOTE: Bridge gates are open 6am to 9pm daily. No fishing or horses on the bridge.
The David Kreitzer Lake Hodges Bicycle Pedestrian Bridge, the world’s longest stress ribbon bridge, was opened to the public in May 2009. The bridge has an inside width of 12 feet and a total length of 990 feet between abutments. There are only two piers in the lake, creating three equal spans of 330 feet each. The bridge is a stressed-ribbon design, at 990 feet long it is the longest of its type in the world. The stressed-ribbon design type was chosen for its narrow profile (only 16 inches deep) to keep its visual impact to a minimum. The T.Y. Lin International bridge engineer team designed an innovative, beautiful, low-impact bridge for pedestrians and bicyclists over Lake Hodges. The bridge provides safe passageway for family and recreational cyclists between the north and south ends of the lake. Bridge architects Safdie Rabines designed it as a trail path floating over the water.
Panoramic photo above is by James Coffee of James Coffee Studios.
What is a Stress-Ribbon Bridge?
The stress-ribbon design achieves a bridge that is a thin ribbon of concrete with very low visual impact to its natural setting across the lake. At Lake Hodges, this structure type uses a 16 inch thick concrete deck to span 330 feet between supports for an amazing depth to span ratio of 1:248. The bridge can achieve such a remarkable depth to span ratio since it is actually a cable supported bridge with the bearing cables embedded within its concrete deck. Post-tensioning is applied to close the transverse joints between the precast deck panels and to give the bridge its required stiffness for live loads.
The bridge was constructed by first building the abutments and piers, then pulling the bearing cables over the piers and anchoring them to the abutments. Once the bearing cables were stressed to the specified tension, 87 precast deck panels were hung from the bearing cables, which fit into longitudinal troughs formed into the panels. After all deck panels were erected and towed into position, ducts for post-tensioning tendons were secured within the longitudinal troughs. Once the cast-in-place concrete for the closure regions reached the specified strength, the bridge was post-tensioned. Finally, a textured surface was applied to seal the seams between the 87 panels and provide a non-slip, attractive surface.
How is the Bridge Anchored in Place? At the north end of the bridge, the horizontal force from the stress ribbon is resisted by a rock anchor abutment, which is standard for stress ribbon bridges. At the south end, there is a deep layer of alluvium, and bedrock is some 50 feet below the surface. This made rock anchors impractical there, and four 8-foot diameter cast-in-drilled-hole piles were used instead.
In North America, the stress ribbon bridge type has only been used a handful of times, and world-wide an example of this length has never before been constructed. This special stress ribbon design required dynamic analysis to investigate effects of live load induced vibrations, dynamic wind loading, and seismic loading. Considerable effort went into the analysis and design of this bridge. However, the extra effort involved has resulted in a world-class bridge that complements its natural setting across Lake Hodges and within the San Dieguito River Park.
The San Dieguito River Park Joint Powers Authority is the owner and operator of the bridge. T.Y. Lin International is the Engineer of Record for the project. Jiri Strasky, Consulting Engineer, collaborated on the conceptual design and performed the independent design check. Safdie Rabines Architects is responsible for its distinctive look. Contractor was Flatiron West.
The bridge is named for David Kreitzer, long-time San Dieguito River Park supporter, volunteer and civic activist.
How was the Bridge Funded?
The total cost of the bridge, including design, environmental compliance, permits and construction was $10,530,000. These funds came from dedicated bicycle bridge sources (federal, state and local), in the following amounts:
- $3,060,000 federal Transportation Equity Act grant (TEA-21), with CalTrans District 11 as the River Park’s state partner
- $1,500,000 from State River Parkway Bond Act funds (Prop 13)
- $920,000 from State River Parkway Bond Act funds (Prop 40)
- $2,000,000 from federal/state Regional Improvement Program funds (SANDAG)
- $2,375,000 from SANDAG TransNet funds
- $675,000 in private donations
Electrical Power to the Bridge is provided by solar power. The solar array enables lighting (trained downward on the bridge surface) in the evenings, along with powering the automatically timed gates on each end of the bridge. Partial funding for the lighting project ($8,000) was provided by the Rancho Bernardo Community Foundation in 2013.
How Can I Get to the David Kreitzer Lake Hodges Bicycle Pedestrian Bridge?
The bridge is located approximately 1000 feet west of the I-15 freeway bridge at Lake Hodges, between the City of San Diego on the south and the City of Escondido on the north. It connects the Coast to Crest Trail on the north with the Piedras Pintadas and Bernardo Bay Trails in the Bernardo Bay Natural Area on the south. The easiest access is to take the West Bernardo Dr./Pomerado Rd. exit from I-15 and go west onto West Bernardo Drive, up the hill. Park in the Bernardo Bay Staging Area on your right at the top of the hill. Walk or bicycle back down West Bernardo Dr. along the bike path that connects the staging area to the bridge.