I wrote about this topic on tech-artists.org (see below) but I didn't quite get the feedback I had hoped for:
We develop games for mobile platforms (iPad, android, windows phone, etc) so obviously we have higher restrictions on what we can implement in our games.
My biggest issue is on how to best use splattmapping together with roads (which have UV's that tile in only one direction) and how to best deal with junctions (X-, T-, Y- intersections, road splits and so on). Using a gazillion of different road textures is a really bad idea due to the fact that we have worse hardware to work with. And at the same time, alpha textures are expensive. Right now we aren't even sure that splatmapping is worth it (although I have said we should look into it).
The first thing can be sorted out with multiple UV-sets. One normal UV-set, where UV-shells for the road are straight - and another UV-set for the splatmap where everything is uniform. But how do you display this in maya when you can only have one primary uv set visible at a time?
EDIT: And I've already considered the most common solutions, such as splitting UV-shells like this:
(which is decent for 90-deg turns and when there isn't much noise in the texture)
...so I'm looking for some outside-the-box-thought-up -ideas.