The agency wants to use Electric Multiple Unit (or EMU) trains. The trains work by having each car generate it's own power. Besides the above-mentioned benefits, these trains are easier to maintain and are lighter on the tracks, thus making the tracks easier to maintain. They're also faster.

Sounds great, right? Well, there's one problem, that being federal regulations stipulating that trains have to be a certain weight to hold up in case of train crashes. Oh, and they have a price tag of $3 billion each.

One option is trying to work with state and federal authorities to come up with some sort of solution. Another option is keeping the train cars they way they are but making the locomotive electric and not diesel.