Factorio Forums

TL;DR
not at full speed of course. please read why it's still important.

I remember when I first hit trains (it was New Hope campaign) it was the first time I had to access youtube. For when I put my first train a loco - it was all fine and I could drive manually to iron ore and backwards, with speed reduced. But when I added stations to visit, it just said "no path". Since that map is very scarce on resources (heck I had to drive a car and transfer iron ore from nearby mining outpost just to build that loco), an option to try adding loco facing the other direction and see if it helps was hard to invest time. What I propose is that trains are allowed to run in backwards direction (with manual controls they do!) just at slower speed. For these reasons:

1. When you add that mission of campaign as part of free trial, you will loose less players on it. For if that would happen to me on trial, it's 90% I would quit to some other game and miss a very great creation with like 120 hours invested in it so far. I was fortunate I had time and passion at that time to get youtube learning.
2. Two-headed trains will gain a little speed boost from locomotive(s) heading the opposite direction.
3. Though that won't be used in a proper factory, it's just logical because a train may move backwards with manual controls.
4. Even if beginner will use single-headed train to transfer ores on a single track without loops, he will soon notice the speed anyway. and think of adding another locomotive. or a loop.

As for pathfinding - just get shortest path for one direction, shortest path for the opposite direction and divide both paths by speeds considering number of locos and their orientation.

Makes no sense, cause you have no longer control about the direction the train comes on a train stop. Which is important for inserter positions.

ssilk wrote:Makes no sense, cause you have no longer control about the direction the train comes on a train stop. Which is important for inserter positions.

You already have that issue if double-headed train is put on track with turning loop. Also, in proper situations trains would never prefer backwards direction for its too slow.

Harkonnen604 wrote:

ssilk wrote:Makes no sense, cause you have no longer control about the direction the train comes on a train stop. Which is important for inserter positions.

You already have that issue if double-headed train is put on track with turning loop. Also, in proper situations trains would never prefer backwards direction for its too slow.

That is the reason why youre usually either using loops or double-headed trains.
Imagine the following situation if your suggestion was implemented:

You have a standard double-headed system. Now you add some turning loops and single-headed trains - No problem so far, however, you might have a setup that looks something like the following:
S = Station benath the main line which can be accessed by both sides, e.g. a siding
O = Turning loop
= = Main Line

===S1====S2===========O===

Now, your single-headed train tries to go from S2 to S1 but has his loco facing towards the loop. However, pathfinding calculates it shorter to drive directly to S1 but in reverse.
This leads to multiple problems:
- The train drives slower and is therefore blocking other trains on the main line.
- The train drives into the station backwards - which train stop should it stop at? (There are 2 stops named the same on either side of the station) Would it stop with the last wagon (now being the front) on the stop on the left or would it stop with the loco on the stop on the right? Wait, thats not possible since stops only work in one direction... Therefore, the train would now be offset by one wagon to the left in comparison to double-headed trains.

Yeah, offsetting a train with respect to station is something I did not think about. Proposal removed Thanks for explaining.