It sounds like you want to "buffer" the highways/roads. If you can get your hands on ESRI's Map Book, vol 24 and vol 25, there are some examples of what I think you want your output to look like. In vol 24, see page 103. In vol 25, see page 32. I call ESRI's Map Books my "idea" books.
You might have to take a liberal interpretation of what needs to be presented. I do understand the constraints you're under.
If you don't have access to ESRI's Map Books, send me an email and I'll send you a pdf of what I'm describing.
Edited by AvgJoe on 05/04/11 09:15 AM.