The reliability and comfort factors can be debated, but NJ Transit delivers tens of thousands of passengers to New York's Penn Station every day; reportedly, 57,000 NJT riders arrive at New York Penn in the peak weekday morning rush hours of 6-10 a.m.  OK, your train arrives at its platform . . . then what? Reporting by Melanie Grayce West and Andrew Tangel in the Wall Street Journal (March 21) has highlighted what riders have known for years: arrival at the platform can be the beginning, not the end, of the struggle. Years ago, when NJT was planning new trans-Hudson tunnels and a new station under 34 Street, advocates lambasted the plan, partly because the "deep cavern" station far below street level would be inconvenient to access, with riders taking 10 minutes or so to reach street level.  Gov. Christie canceled that plan, but is Penn Station any better in this regard? Platforms at Penn are narrow, and jammed in peak hours, and sometimes in off-hours as well. Sometimes two trains arrive or depart simultaneously on each side of the same platform; even worse can be the situation when a train arrives as another is preparing to depart across the platform, leading to collision between riders on access stairs.  Some new stairways have been constructed, but most are still gated shut, not ready to open. Escalators exist, but often are running the wrong way or are stopped; not infrequently, riders who find an escalator running the "wrong way" hit the emergency stop button, violating signs warning against the practice. Amtrak operates the station, which has undergone demolition, underground rebirth, upgrading and modernization since it opened in 1911, but the track and platform layout remains basically unchanged: 21 tracks shared by NJT, Amtrak, and the Long Island Rail Road. The passenger load has increased enormously since the station opened more than 100 years ago, but no new tracks have been built.  In contrast, Grand Central Terminal across town, which opened in the same era, was built with 67 tracks and has plenty of capacity.  What can be done to ease the crush? Building new tracks would take decades and may never happen. Why do the escalators run the wrong way?  NJT, in a familiar refrain, blames Amtrak for last-minute track assignment changes, perhaps due to a train with mechanical problems, or maybe a sick passenger.  The new stairways will open, eventually.  For now, riders can only grin and bear it, and factor the additional time into their trip planning.