The Barnesville MARC train station in Barnesville, Md. (Justin T. Gellerson/For The Washington Post)

Regarding the May 19 Metro article “A possible gridlock solution: Monorail”:

Great, a monorail! Congestion over! Why didn’t I think of that?

As a 34-year rider of MARC trains from the Frederick area to the District, I can testify that the impediments to a mass-transit solution to congestion on Interstate 270 have nothing to do with whether it’s commuter bus (already exists), heavy rail (already exists via MARC), light rail or monorail. The two impediments are cost and convenience.

Cost: A round-trip ticket from Frederick to Washington on the MARC is $16, and it’s more than $200 for a monthly ticket. Not cheap, and you still can’t get rid of your car.

Convenience: You need that car to get from your home to a train station, then you have to get from your last station to your job. Six monorail stations in the farm fields along I-270 from Frederick to Shady Grove? Who exactly is swerving off I-270 to park at them? And stopping at six stations is going to slow that monorail down, as the many MARC stops do now for traingoers to Frederick County or West Virginia. The proposed monorail would run only to Shady Grove, so you’d have to transfer to a Metro train and begin that slow, stop-every-few-minutes journey through Montgomery County and Northwest D.C.

For those (including state legislators) who offer mass-transit schemes to eliminate congestion on I-270, I have a simple question: When is the last time you rode a MARC train or a commuter bus from Frederick to the District?

Don DeArmon, Frederick