From: whheydt@pbhya.PacBell.COM (Wilson Heydt)
Subject: Re: Alliance for a Paving Moratorium (Alert)
Organization: Pacific * Bell, San Ramon, CA
Date: Wed, 6 Jan 1993 00:00:33 GMT

In article <1993Jan5.191826.2404@ntmtv>, adrian@ntmtv.UUCP (Adrian Brandt) writes:
> In article <1993Jan5.004707.15935@pbhya.PacBell.COM>, whheydt@pbhya.PacBell.COM (Wilson Heydt) writes:
> |> Now let's *both* look at reality.
> 
> Okay, but I thought I already was.

Semi, anyway... :-)

> |> You've assumed two things--first that trains *will* be run at the
> |> kind of headways you're talking about.
> 
> Yes, *and* I assumed the freeway lane would be running at maximum
> practical throughput for an *entire* hour (no congestion, no big gaps
> between cars, optimum speed and a generous AVR of 1.11).

I've seen freeways run at or near capacity a lot more often than I've
seen (or read) of rail lines doing the same...  Come to think of it, I
don't think I've *ever* seen or heard of a rail line running anywhere
*near* the capacity you described, but I've seen a lot of full
freeways.  Maybe there's a social lesson in there.  Perhaps cars serve
a need that rail doesn't?  Naw... Couldn't be...

> |> While you are (no doubt) correct that CalTrain (per your example)
> |> *can* run 5 minute or less headways--do they?
> 
> Nope, but we're talking about comparing the practical carrying capacity
> of a rail line to a freeway.
> 
> |> I seem to recall complaints about 2 *hour* headways at some times of
> |> the day...
> 
> From 5 am to 8 pm, the maximum headways are the hourly midday trains.
> Some folks like to vaguely (and misleadingly) claim "CalTrain still has
> two-hour headways" because there is a 2 hour gap between the 8 pm and
> 10 pm trains.  I suppose if for some reason there was a 2 am train, the
> same folks would say CalTrain had 4 hour headways...  Sheesh.

If someone wants to go somewhere, and there's no train for a hour, or
two, or three....  It tends to look like long intervals between
trains.  When was the last time you saw a freeway with an hour between
cars?  (I've seen intercity roads like that.  They weren't freeways
and they weren't in California.  And they *sure* weren't freeways in
the Bay Area!)

> |> The second issue is that, while you have cited *average* occupancy for
> |> cars, you've cited full seat occupancy for the trains.  If I took the
> |> daily ridership on CalTrain and divided by the number of trains--the
> |> figures for trains would be lower, and I assumed that every car seat
> |> is full (say--an average of 5 per car?) the freeway value would be
> |> much higher.
> 
> While assuming full seat occupancy for the train is being somewhat
> optomistic (to say the least!), it is important to remember that the
> fudamental nature of auto and train seat occupancy are very different.

I'm glad you agree that the trains *don't* run full.

> Trains (for the purposes of this discussion, anyway) are open to the
> public and run on fixed (hence predictable) schedules along a known
> route.  The idea is to allow and encourage people to come and fill
> them up.  Autos, as you well know, are quite different.  They are
> typically owned by one person who typically exercises total control
> over how and when it is used.  As many statistics and real-world
> observations will show, auto owners generally don't like to carpool.
> So people don't/won't share an auto much.  Besides, it generally not
> easy to do, even if you want to.  So forget 5(!) per car.  I doubt
> we'll ever even see 2 per car (average, of course).

There is actually quite a bit of informally filling cars up in the Bay
Area.  BART, for instance seems to object to it near it's stations and
one sees articles now and then about BARTs efforts to put a stop to
it.  I suppose it depends on whether you think of BART as just another
mode in a multimode network or The Only Game In Town.  And note that
one of the BART directors wants BART to get in the business of
operating other systems, too.

I have no problem with train systems (or any other transit system)
trying to attract riders.  However, I *do* object to their attempting
to force people to abandon other transport modes to do it.  Simply
put--carrots are fine, but leave the sticks home.

> |> In addition, the need to run trains back to the start point empty in
> |> many real-world scenarios ties up rolling stock, uses energy, wastes
> |> crew time and has to be accounted for in the headways.
> 
> Oh, really?  Since we were talking about CalTrain, why don't you describe
> this in a little more detail for me--especially the part about how it
> "has to be accounted for in the headways".  Be as specific as you can.

Unless there is a near-balance in the number of riders going both ways
on a given line (and given a finite amount of rolling stock) there
will be a need to move empty or near-empty trains in the low-traffic
direction.  Even if there is no one but the crew on the train, it
still takes up a 'slot' in the available schedule.  A car parked by
it's sole occupant isn't occupying a similar 'slot' on the freeway.

> |> At least with the car--the don't 'dead head' half the time.
> 
> Well, it seems that since cars typically have no passengers and only
> have *the* crew-member aboard, that they're "dead-heading" damn near
> 100% of the time :-)  Or to view it another way, we could say the
> typical SOV keeps it's single "passenger" so busy doing the "crewing",
> that it renders him/her a dead head for the duration of the trip...

That's another apples-and-oranges comparison.  The train crew is *at*
work they have no external destination.  Unless the car is a cab, the
driver is using the car to go some where--i.e.  he's not in the car
just to be in the car (we're generalizing here--I am cognizant of
those who are simply driving to be driving, but that's going to be a
very tiny minority at most times). 

> |> (Yes--I know that CalTrain simply stores many of the trains at one
> |> end of the line for long periods of time--but that's the equivalent
> |> of parking cars which Mr. Vandeman deplores so often--and much more
> |> valuable cars--each--at that.)
> 
> Yeah, all vehicles should avoid parking at all cost.  Keep 'em all
> moving all the time!  Seriously though, many of us *do* deplore that
> so much CalTrain equipment is "parked" when it could be making more
> runs to help fill out the CalTrain schedule.  (Lack of equipment is
> NOT the problem in reducing CalTrain headways to a half-hour maximum
> ALL day long...  Lack of demand is NOT the problem either...  Grade
> crossings and safety aren't it either...  It's politics!)

If there is that much demand--what's keeping CalTrain from running
more trains?  (On the other hand--you *did* agree that the existing
trains aren't full--so one has to cast some doubt on the claim that
there is that much demand for additional service out there...)

	--Hal
-- 
Hal Heydt                    |    
Analyst, Pacific*Bell        |            You!
510-823-5447                 |    Out of the Gene Pool!
whheydt@pbhya.PacBell.COM    |
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