This article at The Transport Politic started talking about public transportation in suburban and rural areas, and got me thinking about public transportation in my hometown of Byron, Minnesota. The town was founded back in 1873, and had basically started for the express purpose of supplying the trains that went by on what soon became Chicago and North Western Railway line (now owned by Canadian Pacific subsidiary DM&E).
The town stayed small for several decades, with between 200 and 400 residents until the 1950s. Passenger trains continued to go through town until 1963, though I doubt they'd actually stopped in Byron for a long time before then. The uptick in residents starting in the latter half of the 20th century was probably spurred by IBM building a plant in nearby Rochester, though the general postwar boom probably had something to do with it too. IBM still exists today, but the biggest employer in town these days is the Mayo Clinic.
Anyway, Byron is still rapidly growing, and will probably hit 5,000 residents soon. That got me thinking—when should a city start up a bus service? Of course, it's had at least one bus as long as I can remember: Rochester City Lines has operated a commuter route into Rochester for decades. Today, the buses make three roundtrips through the city. I mentioned Byron's situation a bit in a comment on the article, and other comments seemed to push the idea of actually using the railroad. I'm somewhat doubtful it could work, but let me just ponder that a bit. I've had it as a pie-in-the-sky idea a few times, but could it be practical?
One link in a comment pointed at this page describing how a small line could be built and operated with single-unit diesel railcars (kind of a big bus on rails).
Looking at Mn/DOT's rail map, it looks like the line only sees 4 trains per day—so more trains could probably be added—but segments of it only support 10 mph traffic. Could it be upgraded to handle 60 mph trains or faster? (60 would probably be a bare minimum for reasonable service, since the adjacent highway has a speed limit of 55 to 65 mph.) I'd probably plan for a train that would shuttle back and forth across southern Minnesota, at least going from Rochester west to Owatonna, but a link east to Winona and La Crosse would also be good.
I believe the track is "dark territory" today, without any signals for the trains themselves. While the traditional method of signaling passenger trains has been centralized traffic control (CTC), the federal government has recently been pushing positive traffic control (PTC) which is based on GPS technology and is fairly cheap to install (in theory, anyway). Assuming there are enough sidings for trains to pass each other, dozens of trains could go on the track each day (well, probably just two or so shoving back and forth).
That would be really nice to see. The key would be to get it running often enough that people wouldn't have to think about it. People reiterated in several comments that the key to getting people using transit is making it frequent enough to be a real alternative to a car. There were also a few mentions of Federal Railroad Administration regulations that make these sorts of arrangements nearly impossible. One big issue is that the crash regulations for American trains are much stricter than those for European railroads. Trains in the U.S. have to weigh a lot more in order to meet "buff strength" requirements, which make our trains less efficient, more costly, and harder to manufacture.
Add that to Americans' persistent inability to consider public transportation as something worthy of our tax dollars, and it looks like it will never happen. Kind of sad, since I think one or two European-style railcars running at high frequencies might carry as many or more people into and out of Rochester than the Northstar Line brings in and out of Minneapolis each day with its commuter-oriented schedule.
Unfortunately, I worry that this hope breaks down a lot when we look at the target city. Once you get into Rochester, how do you get around? There's the city bus network, but it seems fairly poor. If you wanted this idea to work, there'd have to be changes to intracity transit to help people get around, and I think trains would have to stop at three or more places in Rochester so people wouldn't have to hit downtown before being able to reach a bus that goes where they need.