In its 1996 Third Regional Plan, Regional Plan Association describes a rapid transit line in Brooklyn, Queens, and the Bronx that could be built almost entirely on pre-existing rail rights of way. The so-called Triboro RX (TRX for short) presents a unique opportunity to provide mobility and accessibility to New Yorkers living or working within these three boroughs, at a fraction of the cost of most transit projects of similar size. This web site documents a possible alignment for the Triboro RX, and a crude estimate of what levels of initial ridership one could expect to see if it were built. The results, as you will see, are encouraging to say the least.