Question about commuter trains lengths...?

Most muni transportation co are federal subsidized..they aren't in the historical preservation of trains. they are in the business of transporting ppl..30years ago it was feesable in Philly to have one car passenger service to some suburbs of philly and off peak and sundays..with the advent of green consciousness increased auto travel lack of infrastructure improvement, rejuvenation of most older cities, train travel ridership has improved and is in demand.

I'm not so sure that the cost of coupling/uncoupling is as negligible as you think. You need shunting staff at the stations where that would take place (assuming there is no automatic coupling system). You would then need additional drivers to take the unused stock to/from the stabling points.I have no knowledge of the systems in Boston/Montreal but assume, being commuter mass transit systems that they are electrified, If that is the case, I cannot see that the fuel costs of running an 8 or 6 coach train as to opposed to a 4 or 3 would be any greater.

Finally, I would make a point made many years ago by a rail manager of the then British Rail at a public meeting dealing with much this point. 'There is no benefit to us at all in having stock sitting in sidings getting square wheels. It is better used in revenue earning service'

Not familiar with the systems in those cities, but they probably adjust the frequency of the trains, running fewer trains in the off-peak than the peak hours. If that's the case, then they might figure they'll still fill up the trains since they're running fewer. They're saving wear and tear by taking whole trains out of service for off-peak hours as opposed to a few cars.

THis was tried in London and led to immense commuter discontent as people wanting to travel at 11AM or 2PM found packed shorter trains. You may have some sort of passion for short trains, but they don't really work these days