"...bicycle freeway..." - great description of many separate paths. They may be intended as "recreational" and have, typically, a 10-15mph speed limit, but large numbers of highly-decorated bicyclists run considerably faster (in pace lines or otherwise) making use of the path for recreational cyclists and walkers uncomfortable at best. Park rangers or other officials who might want to enforce the speed limit would need motorcycles to catch many of them.

"Anyone hear anything about a SMART extension to Sausalito? " - No. And this study has nothing to do with SMART or any kind of rail - it's to assess condition of the tunnel for bicycle use. Realistically, SMART will not extend south of Larkspur in most of our lifetimes, if ever.