The biggest barrier to usability with Commuter Rail in Minnesota is that there is no line running. They keep blabbing about it and never buy the choo-choo and run it on any tracks, but if they did actually do it they are already designing in the usability problems.
A commuter rail transit line is proposed from Minneapolis to St. Cloud, oops, only to Big Lake, which is about half the 60 mile distance. Now, I am sure everyone actually wants to go to Big Lake (population 6,063 in 2000) instead of St. Cloud (population 63,348), or maybe not, it could be considered a usability problem when the line terminates in a whistle-stop in the middle of nowhere and not in a real destination.
"Commuter Rail" as it is made in this part of the world means leasing tracks from a freight rail company and usually much of the line can be preempted by the freight trains over "commuter" traffic. This will play havoc with schedules, but hey, who cares about people and their pesky "jobs" or "medical appointments", if they wanted to get to a destination on time they should drive like a real American. Freight traffic also seems to cause crashes and makes for a bumpy ride. I can hardly wait to lurch and thump my way to Big Lake like a drunken hobo!
Of course, then there is the "fare". According to the St Paul paper the first proposed fare was declared too low by the Governor of MN. From what I saw as a description of the fare system it had nothing to do with the other Metro Transit fare systems, like the Light Rail Transit (LRT) line or the bus system. The fare will be distance related (to be "fair") unlike any other fare structure in the 50+ mile diameter Metro Transit region. So instead of a simple fare structure a complex distance system will be grafted onto the current system. Complexity of fare structure is a usability barrier. Yup, the choo-choo will cost about 5 times more than traveling from Stillwater in the East Metro to Mound in the West Metro which is close to 20 miles farther than the entire choo-choo line. With deals like that I am sure they will get lots of riders.
But will the graft take? It will undoubtedly be a totally incompatible fare system without the ability to pay for train fare with currently used prepay cards (also not accepted on LRT) or accept transfers or be seamlessly integrated with the current Metro Transit fare structure.
The managers of the Metro Transit system seem to have taken advanced courses on how to make system wide annoyances to drive down ridership. Fare practices and the methods of system integration will be difficult to change in the future once the bad methods are in practice. The "momentum of stupidity" will make its own inertia and to change in place practices will be difficult and expensive. Congrats to the managers of Metro Transit, everything is going according to plan for your goals.
Transit Usability Articles