In my opinion, the map is subordinate to the story. It is a tool to help you to tell the story, either by helping you to communicate with your audience or by helping your to better understand your own world. If it doesn't serve that purpose, it needs to be modified, abandoned or redone to suit.

When getting down to the specifics, though, consider how much time has passed since the collapse. If this world has crawled back out of the stone age all the way to a new Industrial Revolution, we could be talking in terms of millenia. Not much of our modern world (and I would assume the greener, more organic future world) is likely to survive more than a few centuries. We don't build to last these days. In addition, the massive quantities of resources available in a city or along a highway would ensure that those structures would be used as quarries and mines, further reducing their mark on the land.

On the other hand, if civilization rose faster this time around because people could reverse-engineer tech from what was left behind, then you'll definitely see more signs of the older world.

Another thing to consider is that the settlements of the old world are probably located in places where it is natural for a settlement to exist. Las Vegas notwithstanding. So the new civilizations are fairly likely to go ahead and build on top of the old cities. They will probably appropriate the old roads, since they're already there and already lead to useful places. So your existing map may well show the same features and need only minor adjustments.

If you intend to set the story in a specific modern geographical area, though, then you'll probably need to start from scratch in order to get the landforms and general settlement locations to line up.