From: CCJPA Vision Plan Volume 1

"Between Martinez and Richmond, the options to straighten the existing many curves between using an engineered series of “cut-and-fill” modifications to establish a solution where higher speeds can be achieve using the existing alignment is directly contrasted against the option to generally follow the BNSF Franklin Canyon route, albeit with two sections of tunnels to avoid steep grades and to ensure re-connecting with the existing route in the Martinez area. Either routing option has its costs and environmental and political challenges,and in the initial analysis, either option appears to be similar in order-of-magnitude costs."

Here is the link with all the pdfs and maps.

https://www.capitolcorridor.org/vision-plan/