Interesting stuff...I use a Survey package for road design and import the DXF into Maya...though it does hate metres...nice one on the texture thing Jay. Although I use civilcad the process is the same I think. The only difference is I can input real world data (ie horizontal and vertical curves) to represent a real road with real crossfall etc etc...the create left and right offsets that represent the edge of the road...then I can create a DTM of this and I have my road. Only tried it once in Maya...let us see how you do mate and I might try myself...
cheers bullet
bullet1968
"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes