Another interesting discussion, with good points on both sides.

But something that should be noted, the NEC with its multiple
service providers is not as user-friendly at it could be, as
implied by a previous poster..

For example, you can go between Washington, D.C., and Baltimore
on either Amtrak or MARC -- but the tickets are not interchangeable
and you cannot buy a combined ticket that would let you make
part of a trip on Amtrak and part on MARC. (Example, New
York City to Baltimore on Amtrak and Baltimore to some point in
Maryland on MARC.)

On the other hand, many European metropolitan regions have long
had so-called unified fare districts. I'll use Vienna, Austria,
as an example, as that's the city I'm most familiar with. Within
that fare district, which extends out a number of miles from the
city limits, any *time-stamped* ticket is equally valid on all
forms of public (and some forms of private) transportation.

In other words, you can buy a ticket from a streetcar, subway,
or national railway vending machine, and for the specified time
period (which I think is two hours) you can ride on trains,
streetcars, city and regional buses, subways, and even some
privately operated bus lines. I don't know all the details of
how the revenue split works -- but it works. You don't need
any kind of transfer to change lines of the same system or
even different modes of transportation.

Similarly, in Europe, you can buy a through ticket from one
point to another -- even if it involves trains operated by
different national railways.

And, in case anyone cares, though I live on the East Coast, I
have traveled Los Angeles to San Diego by train several
times. I've also traveled on both the San Diego Trolley and
BART at various times.

-- Ernest