The SJ Mercury reports that 17 of the 26 proposals were released to the public: Proprietary information was elided. There's no explanation about the other nine proposals' absence. The proposals can be downloaded at this link. I've taken a look through some of the proposals, and these are mostly cover letters and answers to the RFI (request for information) that address the company's history and knowledge. The actual engineering proposals aren't part of this disclosure. So we learn that Google is a big firm, but not the nitty-gritty.