[thomaslkjeldsen]

> Track capacity at night is often severly limited by maintenance work

Makes one wonder what it would do to the economics of train transportation if maintenance work was required to be carried out during daytime and passenger transportation was optimised for comfortable sleeper trains.

[bluGill]

Kill it. Even assuming we are limiting ourselves to long distance trips (that is commuting to work is still allowed to use tracks during the day), and hand wave away some tricky where to draw the line issues.

Trains work best when the track is used. That means trains need to leave often to keep the track busy. Leave at 9pm, and arrive at 7am sounds great, but you don't get anyone leaving at 2am, which means there isn't enough users to pay for all the infrastructure needed.

Day trains work because some people leave at 8am, some noon, some 6pm... You need enough riders to fill to 70% capacity 3 trains per hour for 13 hours a day just to break even on all the costs of running a train for a reasonable price. (the numbers are approximate and depend strongly on local details). The more often you can run nearly full trains the better. Your night trains can't do this.

[toomanybeersies]

That would probably cause a whole lot of problems for commuter rail.