blacktop/macadam

[AAllan at AOL.COM]

DARE has an extensive entry for "macadam," complete with map: it's chiefly
Northeast, MidAtlantic, and North Central (esp. Ohio) for this definition:
"originally a road pavement made of layers of packed crushed rock, sometimes
strengthened by applying a bituminous binder; now usually blacktop or a
similar paving material."
No entry for "blacktop," presumably because the editors didn't consider that
term regional. - Allan Metcalf