I am working in Map 2.0.
I have a map that shows highways as having two parallel lines with a solid dash in the middle. By solid, I mean it is the width of the two parallel lines, but is dashed.
The two parallel lines list as LWPOLYLINE width a 0 linewidth. The solid, dashed line lists as a LWPOLYLINE with a width of 7.5 and length of 15.
I'm trying to find this linetype, or figure out how to build it. I can email anyone a sample if needed.
I've tried to simulate that linetype before, but to the best of my knowledge, a single linetype that would create what you're after isn't possible in AutoCAD. In MAP2005, you could use a display style to get something close to it. A typical linetype definition is a series numbers representing pen-up/pen-down, not offsets, etc. One other possible route that I looked into, but found to be too much trouble, was mlines. Good luck to you, but I don't expect you'll find a convenient answer.
one thing before you go too far with making an mline definition is that mlines won't do arcs. if you want your road to have too many arcs the mline is pretty much a waste of time. i don't know if it's possible to query the road and get it to display the way you want with thematic mapping. i haven't tried that yet. the way i've always done it is just to do a polyline for the fill with the width you want and then to offset the road edges to a separate layer with xoffset.