Shorter Trains?

Is it my imagination or are the trains on the north side shorter than normal these days?

I say on the north side only because I never go south of boston so I have no idea whats going on down there. But up north, I think I saw a train on the lowell line last night that had three singles and thats it. Are they running out of cars? Or is traffic just way down? Ridership I mean.

As a regular Lowell line rider, 5 car trains are the norm for my train about 8 out of 10 times, with the other 2 being a four car set. I have to imagine that car supply is dictating this more than some attempt to adjust sizes to passenger loads, but one never knows. The real fun is when a 5 car train shows up but they're only operating 3 of them, but that's pretty rare and usually seems to be the result of being short a conductor.

What really counts is, have outbound passengers ever been left behind on the platform because the train got too full?

There is great discouragement from using public transportation to get to major evening events in town when there aren't enough trains to get people back home.

Running with closed cars, e.g. 5 coaches with only three in use, has gone on for a long time to save on the cost and effort of coupling and uncoupling cars. If the closed cars can be opened up suddenly in case of an unexpected crowd,k even without an extra conductor, that would improve service when really needed.

At least once in the not too distant past, Philadelphia (SEPTA) limited ticket sales for a specific and unusual heavy travel day to improve predictability of getting on a train after ticket purchase). They had to operate slightly below full capacity to make it work, a move that detracts from profit making in a private system like transit systems were a hundred years ago.

I haven't ridden T commuter rail recently but I did ride once something like 5 years ago (Needham line inbound) when there were closed cars in the consist.

DG: The SEPTA Regional Rail special service limitation that you refer to was for the September 2015 Papal Visit
by Pope Francis to Philadelphia - and to a lesser extent for the Philadelphia Eagles Super Bowl victory parade
back in February 2018 for the SB 52 win over the NE Patriots...Both events are well covered in the SEPTA Forum.
SEPTA RRD learned a very harsh lesson with the extensive service problems the day of the Phillies World Series
victory parade on October 31, 2008 - another interesting subject in the SEPTA Forum archives...

As an occasional SEPTA RRD rider over time I noted that closed cars were most likely done depending on how
many train crew members were available - and the time of day. Cars would sometimes be opened as needed.
Something that can irk riders is having closed cars when either all seats are taken or there are standees in
cars that are open depending on the individual situation and the particular crew involved - MBTA looks to
be much the same addressing this subject...MACTRAXX

Live right next to the NHML and not seen any 3 single consist. 3 singles with at least one double decker has been the shortest, but usually 4 or 5 plus a DD. Recently new dd control cars are starting to show up and run 4 car as D+s+s+D.

4 cars is the minimum required for adequate braking. Trains with fewer than 4 cars are subject to speed restrictions.

How does that work? Why does fewer cars mean less braking? Yes you have less braking wheels but you have proportionally fewer lbs too?

Presumably a coach car adds proportionally more braking force than weight to a train. A passenger coach might comprise 10% of the total weight of the train but 15% of the braking force in full service application (numbers for the sake of example only). I would guess that to be allowed to operate at line speed you'd need a certain brake force to weight ratio that can only be achieved with four or more passenger cars.