Advantages re: train networks

[L. Spooner Inc]

So I spent hours designing a complex train switching/merging/etc. network outside a city and then it struck me to wonder whether it really made any difference. Simple, single-purpose lines A->B->A might actually be more efficient, since there's never any delays on the line. Sure, you need more stations, but they're relatively cheap. Other than aesthetics, is there any game reason to sweat over signals and merges and cyclotrons and s*** instead of just creating spaghetti tangles of one-purpose lines?

[jfs]

It may make sense if you play with infrastructure maintenance costs enabled. Then the cost savings from maintaining a network with infrastructure shared between lines, versus maintenance of much more track on independent lines, may make a significant impact on your budget.
Also, at some point you will probably run into problems with routing new lines past the existing ones, since rails in OTTD generally has to run on the ground.

[audigex]

There are a few reasons I make a train network rather than point-to-point lines

1. Infrastructure maintenance costs quickly add up if you've got 5 mostly-empty lines instead of 1 full one
2. Realism: many people like to make "realistic" looking networks and track layouts... 4 lines taking the same route looks weird
3. It's more fun/challenging: I have to think more about track layout, plan ahead, and regularly have to go back and improve things