This project consists of two bridges: the Greenleaf St. on-ramp undercrossing and the Ventura Blvd. undercrossing. Both of these are single span bridges. One is approximately 32 meters long and 16 meters wide composed of a cast-in-place post tensioned box girder supported on a cast-in-drilled hole and driven steel pile foundation. The other bridge is approximately 39 meters wide composed of bulb-tee girders supported on cast-in-drilled hole foundations. Retaining wall and sound wall work is to be done too. This project extends the current auxiliary lane on the northbound I-405 past the Greenleaf Street off-ramp to the U.S. 101 connector. The project also will close the loop on-ramp from eastbound Ventura Boulevard and construct a bypass of the Ventura Boulevard/Sepulveda Boulevard Intersection using Dickens Street. The Sepulveda Boulevard on-ramp will be reconfigured to separate the U.S. 101 connector on-ramps from the northbound I-405 on-ramp.

This Gap Closure/Flyunder project will enhance safety by reducing the need to cross several lanes of traffic to access the connector. Combined with the I-405 auxiliary lane and the connector widening projects, completed in 2003, the gap closure project will increase freeway capacity, reduce congestion and improve traffic flow at one of the busiest interchanges in the State