Routes downloaded with trackwork that calls for repair and/or adjustment, or simply altering a route for whatever reason - What are some ways to approach this?
Use layers to lift the track off the route (trackside stuff into another layer below)? Does this facilitate inspecting and changing/repair?
How to tell why derailments occur? Do attachments of crossings and roads affect the continuity of trackwork?
Thanks!
You do mean routes off of the Download Station?
If so the clone the route - There are two ways to do this.
The easy way.
Open the route up in Surveyor.
Make a change.
Choose Save.
Your route is now yours.
Since route is now "yours", go ahead and edit to your heart's desire. There is no need for layers or anything fancy. If you want, you can put all the track-objects on their own layer, but this becomes a painful ordeal when changes are necessary, and stuff doesn't always get put on the layer when you want, with trees suddenly now on the track-objects layer, or track on the track-objects layer. Ideally this is a great idea, but the implementation I think is poor, and there is now another layer of thinking needed because there is no way at all, period and has been this way forever, of knowing which layer you're working on. Yes... we're supposed to get a fix for this sometime soon(tm), but we'ere not holding our breath. With that said, think KISS. It'll make your life much happier.
Yes a track disconnected from something can cause an issue and cause derailments, and derailments are usually caused by misaligned track splines either where the track joins other spline ends - those circles, or where the track attaches to a fixed-track object such as a road crossing, or to an industry track such as a station or industry. The other issue could be a junction missing a lever.
If you suspect there's an issue with the track, the best way to find it is to ride along with the AI.
Tell the AI to drive to the opposite end of the route. If the AI balks and complains that it can't plot route to destination (The message is similar to that), drive yourself for a bit then issue the command again. The AI will stop and complain more. Keep doing this and eventually you'll run into the spot along the line.
Tracks should be smoothed out. To ensure this, click on the spline circles with the adjust height tool (F4 then H for keyboard shortcuts if you want to use that.). There is no need to move anything; just click on the track circle. This will smooth out the track and get rid of any broken joints. When the track spline-point turns from white to yellow, you are golden. Sometimes clicking may not fix the problem and there maybe something else. There are cases where when adding track there's an extra spline point that somehow aims deep into the ground and comes up again and produces a weird junction. This isn't a bug and it's caused by clicking and placing track. The other issue too is sometimes the circles will look connected, but they are not. One circle will be yellow, but the other underlying track, almost exactly in the same spot, is not connected but appears that way. You can see this by looking carefully at the spline point. If the spline point appears slightly yellow with a white tinge, it means that one of the spline points isn't connected and level.
For industries and other fixed-track assets such as road crossings and stations, check that the track is really connected. This can be tricky, and sometimes the only way to tell if the circles line up is to drive manually and derail. If you suspect this is an issue somewhere, without derailing, take your mouse and drag the track using the move track "M" tool by clicking on the spline point at the fixed-track. If the connecting track slides, this is your culprit. If all else fails, add in another spline point nearby, delete that segment between the fixed-track object and the new spline point, and then drag the track to the fixed-track object.
For missing junctions, the AI will complain with a message like "Unable to plot route, junction missing lever." The newer variant of this is unable to plot route after Junction xxxxxx junction missing lever or something like that. This helps because you can find junction xxxxxx and then search from there. The other way is to drive. Keep driving yourself slowly in the problem area and you'll eventually come across the problem when you find yourself looking down upon your locomotive with a big yellow X floating over it.