Simplifying divided highways into a single line

Because mapping divided highways at a small scale has too much detail, we can simplify the lines rather than redrawing them in Adobe Illustrator.  

The basic concept

  • Duplicate the roads layer
  • Make desired lines black, about 4 point
  • Rasterize the layer
  • Use image trace, the Line Art option
  • Use the original roads layer for referencing attributes in MAPublisher.

Benefits of this approach

  • Simplification is done inside Illustrator
  • Huge time savings over redrawing
  • Clean, but accurate, lines

Do you have a better approach?

If there’s a way to do this in QGIS, I would like to know.