Beyond the financial benefits, All Aboard Florida passenger rail also promises long-term environmental benefits. Giving frequent business travelers and families the option to choose an energy-efficient rail service over often-congested roadways and airports lowers the state’s overall carbon footprint. Initial studies predict this new rail service will take more than three million cars off Florida’s roadways annually.
Three million cars off the road would mean just north of 3.5 million or so passengers assuming an average occupancy of 1.2 per vehicle, which is rather interesting in light of my previous attempt to estimate the ridership they'd need to break even.
I do have to say that the paragraph which immediately followed the above does not fill me with confidence:
All Aboard Florida will select equipment utilizing clean diesel engines that meet stringent Tier 3 federal emission standards. Clean diesel systems are both fuel efficient and environmentally friendly. Clean diesel-powered vehicles produce up to 25 percent less CO2 emissions than that of comparable gasoline engines, resulting in better air quality, and 30 percent better fuel economy, resulting in a smaller environmental footprint.Look like the PR person did a bit of context-free copypasta with that diesel vs gasoline comparison.