To me the lowest-hanging fruit is to add frequency to comparably short segments currently covered by LD. I don't think either of these categories are low-hanging fruit:
--Trying to convince more people to take most existing trains. It's always hard to get people to change their travel habits, and enough people perceive the train as old, slow, unreliable, inconvenient...often based anecdote...that it's probably a tough sell.
--New routes. In addition to the regular barriers (freight line cooperation, equipment, operational funding, etc.) the basic existing infrastructure is often inadequate and the "we haven't had trains in 50 years, why would we bring that back now?" opposition is strong.
The best shots at comparably-easy success is to bring state-supported service to large city pairs which currently have just LD service. A few reasons for this:
--There is already precedence for Amtrak service in the community and an existing customer base, though smaller than it could/should be
--The new service is likely to be much more reliable and will benefit from the "newness" factor
--The LD service is often poorly timed, routinely runs very late and/or at peak times sold out
--The infrastructure already exists, and though there may well be case-by-case incremental improvements needed the basics are there
Here are some of the situations with the best potential for 1...or possibly even 2 or 3...trips to be added on top of the existing LD service:
Atlanta-Charlotte
Chicago-Kansas City
Chicago-Cleveland, possibly extended to BUF and/or PIT
Chicago-Minneapolis (already in the works)
Los Angeles-Tucson
A couple more with potential but perhaps not a slam dunk based on other factors such as market size/weak intermediate points or speed
Chicago-Memphis
Chicago-Omaha
Fort Worth-Austin
Orlando-Jacksonville
Orlando-Tampa
Those last two or three in particular might be best served with a comparably frequent service like 4-6x/day...they are short enough that just overlaying one or two trains on the existing LD wouldn't really serve the market very well. Same with something like Austin-San Antonio.
Among the markets which just seem dangerously slow to be successful for a short-haul train to supplement the existing LD are these:
Houston-New Orleans
Houston-San Antonio
Pittsburgh-Washington
Dallas-Little Rock
Atlanta-Birmingham
Reno-Emeryville/SF
Los Angeles-Emeryville/SF
New Orleans - Memphis
Chicago-Indianapolis
That last one is especially painful. The drive from Indy to Chicago is three hours, and the train is roughly five. Make the train do it in something like 3:45 and a handful of daily trips would generate 400k riders without much effort. But that is decidedly not low-hanging fruit. And particularly given that a lot of Indy's wealthier travel-inclined demographics are found in the northern suburbs (Carmel, Noblesville, Fishers, etc.) backtracking to downtown Indy to catch a five-hour train to Chicago is just not appealing. As I type this (mid-day) Google Maps has the drive from Carmel to Chicago Union Station at 2:53, while the drive from Carmel to Indy Amtrak is 0:31. You can be well on your way to Chicago in the same time it takes to get to the IND station from much of Indy's affluent northern suburbs. And even for those in greater Indy who won't make the drive for whatever reason, the bus roughly as convenient and substantially faster than the train.
To be clear I did not scrutinize the "low-hanging fruit" against state political nor host railroad challenges. They are real but also sometimes hard to predict in terms of how tough they are to overcome. Any of these routes could have the practical brick wall of "you'll never get a cent out of the State of X" or "Railroad Y is already oversaturated between Dumptown and Stumpville Junction and will never allow another passenger train" concerns. But any expansion will have barriers, and I think these are as ripe as any to be low-hanging fruit if those barriers can be scaled.
