IIRC, all the buses here in the Austin metro run on NG.
Safe from Barry’s wrath
He wouldn’t want to shut public transportation out. He wants to get rid of non-GM-Volt cars to force more people to depend on freedom-restricting gummint transportation.
But if he ever does want to shut it down, he should remember that natural gas is mostly methane and that he could demand that not one molecule of methane can leak out of the refueling system.