Intro.: Roller coasters don't have to be thrill rides. One of the best parts of any coaster I've ridden is near the end if the Magnum Force roller coaster at Cedar Point in Sandusky, Ohio. It concludes with a fast trip straight over some very small hills, with each lifting riders off of their seats, pleasantly defying gravity. I've been on it a few times and it is about the only ride (in addition to Soarin') that always ends with the audience breaking out into applause. These negative Gs are the opposite of the miserable Gs on Magic Mountain's Goliath.
And part of what makes tall coasters so breathtaking and Big Thunder at night so interesting is, of course, the scenery.
Proposal: Three coasters linking WDW's three southern parks. Coasters are far cheaper, mile per mile, than monorails. And they don't have to be over 140 feet tall. (They should be shorter than Spaceship Earth and other tall icons of the parks.) They shouldn't be thrilling, just pleasant fun for almost the whole family.
1. One between EPCOT and the Studios.
2. One between the Studios and the Animal Kingdom.
3. And the longest one connecting the Animal Kingdom and EPCOT.
All three of these parks would be linked to each other by non-stop rides with just three coasters.
There are at least two large spaces that could be used as stations in World Showcase in between World Showcase pavilions on land where pavilions were not built. Or the EPCOT stations might be near the monorail to the MK.
And three additional, far-shorter trains could link moderate resorts to (very) nearby parks as follows:
1. Port Orleans connected to EPCOT--specifically to the land between China and Germany.
2. Coronado Springs to the Animal Kingdom.
3. And the Caribbean Beach Resort to the Studios.
Obviously this might not even make a dent in the need for busses, but connecting each of those moderate resorts to one park would make them a little bit more attractive.
Maybe what I'm proposing aren't really roller coasters, but inexpensive, fast, and fun trains able to ride over roads without CMs on board.