Underpass rail-type bug.

[EoRaptor]

Actually, this is two bugs in one post!

I'll start with the major one. Rail passing under a bridge does not have to be the correct type for a train to pass over it. If you see the first screenshot (underpass-clear), you'll notice that the rails under the bridges are type monorail, while the attaching tracks on either side are type maglev. Maglev trains have no problem at all driving over the monorail track, and do so at full speed, as demonstrated in the second screenshot (underpass-maglev). You can use the rail conversion tool to 'swap' the rails under the bridge back and forth between monorail and maglev, and the trains don't seem to notice the difference. Convert a rail on another section of track, and the train stops as expected.

The second bug is how I discovered the first. If you use the rail conversion tool to convert long stretches of rail with drag and release, and that rail passes under more than one bridge, only the first bridge you encounter from where you started the drag operation will be converted. I did this, and didn't notice the rail hadn't converted until much later, when I went to update the lines that were using the bridges. The two bugs don't seem related beyond this, because switching the rails back and forth still has no effect on whether a train can pass. Not that the screenshots show both underpasses with monorail track, this is from me fooling around trying to figure out the extent of the bug. Originally, the bridge on the left converted fine when I did the drag and release.

I've also attached a savegame, if anybody wants to see it in action, though the rest of the map is a jumbled mess of me fooling with different station and rail arrangements.

[Prof. Frink]

This is an old bug from TTD. Also applies to rail on level crossings.

[mispunt]

I had the same problem yester when converted the normal rail to monorail. but when I did it for the second time it just did what it should.

[EoRaptor]

This is an old bug from TTD. Also applies to rail on level crossings.

Ah, so it's tied to the collision code. I don't know if it'll be easy to fix then. Maybe, eventually, OpenTTDS can have both a simple and a strict mode, one that allows the old TTD niceties, and one that is anal retentive about this stuff.