Wasteland Map - How do you draw ruined roads and other urban furniture?

[wormspeaker]

The map covers an area roughly the size of Greater London or a similar megacity.

And yes, there's a small lake.

Then at this scale and style, the city would simply be a blob of varying tones of gray following the contours of the terrain. You couldn't tell it was ruined form this scale. That is unless you have one of two conditions.

1.) The ruins are old. Thus in this case you would add some green back into the gray as the vegetation tries to take back the city.
2.) There was large scale damage to the city. (Such as from nuclear bombardment, for example.) In that case you can draw craters in the city and surround them with slightly varying tones of gray to indicate damage radiating out from the crater.

Alternatively you can just start adding labels and icons to the map to indicate the conditions. Such as "There be radioactive dragons here." or "Beware of juiced up hooker Nazis."