Firstly, as you need the right tools to do any job pop over to
http://www.mcs-software.it/rs/MergeRoute_en/index.htm and download RW Merge Route. There's no installation needed, just shove it in a directory of your choice (I made a new one named "RW Route Merge" ) and forget about it for a while.
The tool wasn't written to enable us to merge any old pair of routes together, and it
cannot be emphasised enough that
if the origins of the routes differ, forget it. Whilst Nick is correct in saying you can juggle the tile names/co-ordinates it really is more bother than it's worth; certainly in the wee merge I was involved in it would have been quicker to relay track/add scenery than to mess about with renaming and editing the .bin files for tiles.
The whole idea of the tool is to enable collaborative route building, or more specifically collaborative track laying, Scenery, roads and lofts are easy to share about with others as those items are only referenced in their respective tiles but track throws a spanner in the works by having, in addition to track tiles, Tracks.bin---think of it as a master index of the track and track linked objects such as signals and speed limit signs. Because of this 'index' one guy cant lay track at the northern end of a route and his mate plod on with track in the south because they'd both have different Tracks.bin files.
Essentially this piece of software combines those two files into one.
Those of you who have South West Wales will no doubt be full of awe and praise for it, and until now blissfully unaware that the section from Pyle to Bridgend wasn't built as a
progression of the current route but ripped out of an older version and merged to the 'guts' of what you can download. Those of you who don't have the route, HANG YOUR HEADS IN SHAME! and pop over to
http://www.oakwood-shed.co.uk/sww5/sww_route5.html immediately!
This short, and admittedly not very detailed stretch of the route became merged more by accident than intent--Peter passed the route over to me to sort out a unified track rule and odds and sods relating to track and being the impatient old-so-and-so he is got bored whilst waiting, and laid track and some scenery down to Bridgend. Obviously this meant there were two versions of the route on the go, neither being compatible with the other. After reviewing just what would be entailed for either of us to re-do depending on which version became the 'master copy' we decided that there was less work involved by going with the revision I'd worked through and that the stretch to Bridgend would have to be done again. Peter had turned his attention to the northern part though, so the Bridgend bit became something 'to do later'
I know, I'm waffling...but if you understand the rationale it becomes a lot clearer.
More out of interest than as a full blown project we decided to give this merging tool a go.....worked great at merging the track and scenery etc but broke loads of stuff all over the route---badly rendered pointwork, buffers appearing in main lines etc so that was shelved. We don't like being beaten though, so had another go---this time looking at it from the collaborative building angle, and only merging the bit that wasn't common to both. The version that had the Bridgend stretch was edited so that the Bridgend stretch was
all it had, and the scenery, lofts and road tiles cut out of the Bridgend version as they would be simply pasted into the merged version.
This worked...worked very well with nothing more needing to be done to the track---no break around the jointing area or issues elsewhere. Letting the software do just what it was designed to do (or at least seemed to be designed to do) tipped the scales in our favour.
Download it, have a play with a new route,just a mile or so of track to start with. Clone that route and extend the track another mile or so and then delete the original track from that clone.
Then merge the original and the extension---see if it works for you.
One more time though, and it really is important:
The routes to be merged together must have the same origin!!