LOS ANGELES (CBSLA.com) — Construction will continue on I-405 after crews successfully demolished the existing part of the Mulholland Bridge during Carmageddon II.

“We want to make sure that we give everybody a realistic expectation as to when we finish our project, so next year, 2013, should be the completion of it,” Caltrans’ Patrick Chandler said.

Crews will immediately start to rebuild the north side of the bridge, which will mostly stay open during construction.

A 10-mile carpool lane gap will be filled in to create the nation’s largest contiguous HOV lane between the San Fernando Valley and Orange County.

Crews will be working on paving the carpool lane, improving about two dozen on and off ramps and widening the Skirball Bridge.

Last week crews finished widening the Sunset Boulevard Bridge.

Metro and Caltrans say the completion of the $1-billion Sepulveda Pass Improvements Project will hopefully improve traffic.

“It helps, as an essential, to ride together to remove more vehicles from the main line and get everyone moving along quickly and also remove the air quality in Southern California,” Chandler said.

Officials aren’t releasing the exact timeline, but encourage motorists to visit Metro’s website for updates.

RELATED STORY: 405 Freeway Reopens After ‘Carmageddon II’ Construction Ends Ahead Of Schedule