Don't forget about trains and ships. Freight trains are among the dirtiest poluters in LA, so I've heard, and Biodiesel can be much cleaner than petro-diesel. This means you'd be shifting a huge portion of freight not only to a renewable source but to a cleaner fuel as well. Most all freight ships are diesel as well, which again are typically excluded from our on-road fuel stats, but if biodiesel was plentiful enough, it could be used in freight ships as well. Diesel is an extremely heavily used fuel for commerce - even if hardly any personally owned and operated vehicles adopted it in the next 5 years, the commercial applications are huge.