also im not sure if your doing the same thing but I usually start working on my level in the grey grid development texture then once all my basic brushwork is done i make all textures the nodraw texture then i go around and texture everything by hand only texturing the things I can see.
possibly the easiest and least time consuming optimization process that ive found.
also, dont know if you have ever noticed but roads never do that, eg: never square roads, they always curve.
needs a valet parking type thing with a largish overhanging roof at the entrance and a carpark round the back or underneath it
