Reader question: why does the Mulholland bridge need to be replaced on 405 project?

David, a Source reader, recently emailed with this question about the project to add a northbound carpool lane to the 405 freeway over the Sepulveda Pass.

He wrote:

Why does the Mulholland bridge over the 405 have to be replaced?  There is plenty of room to run the Northbound on-ramp lanes from Mulholland to the right of the large support column before having the lanes merge with the 405 Norhtbound lanes.  Replacing this bridge has to be one of the more expensive and time consuming aspects of this project.  A lot of time and money could be saved, by not replacing the bridge.

We forwarded his question to the Metro officials working on the project and here’s the answer that they emailed back to us:

During the environmental process the department (Caltrans) considered various alternatives to try to preserve the bridge; however, the design requirements of the project based on the needs of the project precluded the possibility of avoiding the adverse effects to the Mulholland Drive Overcrossing structure.

The proposed project requires that the HOV lane, the mixed flow lanes, the shoulders, and all other geometric features must be designed to meet the latest Caltrans and FHWA standards. The existing roadway width at the Mulholland Drive Overcrossing structure is not sufficient to accommodate the required width.

The department has agreed to resolve the adverse effects of the undertaking of the subject historic property through the execution and implementation of a Memorandum of Understanding (MOA) with the State Historic Preservation Officer.

If you have questions about Metro policy or projects that are outside of routine customer service inquiries, please email us at and we’ll try to get an answer for you.

Categories: Projects

Tagged as: ,