T he report below from the California Planning & Development Report (CP&DR) News Brief confirms that the purpose and need of the SR-710 Toll Tunnel project is to move freight. It also states that the people most affected by the project prefer a tunnel to a surface route. (We prefer a multi-mode solution or no project at all.)
March 23, 2015 CP&DR News Brief:
Caltrans Details Options for Extending, Expanding 710 Freeway
Los Angeles County Transportation officials are considering multi-billion dollar plans to close the notorious 710 freeway gap and increase capacity along the entire freeway. The freeway, a vital trade arterial connecting the ports of Los Angeles and Long Beach, abruptly ends in South Pasadena without connecting to the 210 Freeway, four miles to the north of the 710 terminus. This gap has been blamed for causing traffic throughout the Los Angeles freeway grid, especially because of traffic from trucks traveling between the port and the warehouses of the Inland Empire. A draf t environmental impact report by Caltrans estimates that a tunnel under South Pasadena — which is preferred by residents, who vehemently oppose the taking of homes for a surface right of way — would cost between $3.1 and $5.6 billion. It would take five years to build.
Here's a link to the report, the first paragraph is the SR-710 and the second paragraph is on the I-710.