Woah... stop
"chunked" is not meant in the terminology of a chunked terrain. Chunked models don't work, though. I meant simply that you build your street model and after that you take a look and slice it into many parts -- chunks so to say.
But what do you mean: "be sure to share textures by link them to external textures"? How do i do this?
Imagine you've got 8 road-chunks with each models texture summed up you got a total of 8 textures or more (sideway, special signs or so) -- but originally, your very big model had only.. e.g. 3 textures or so. So: save your 3 textures as external files. Inside each chunk dont save the needed texture(s) INSIDE the model, but check the checkbox "extern" and choose the texture with the dialog: that means that the engine takes the model, looks where the imagefile on the HD lies and loads it. When 8 models refer to one external texture file it is just 1/8 of the memory in use than before (whereas you had saved the 8 textures INSIDE each model).
Download the latest release and have a look into the skin manager of MED and you know what I mean.