  A road map can be interpreted as a graph embedded in the plane, in which each
vertex corresponds to a road junction and each edge to a particular road
section. We consider the cartographic problem to place non-overlapping road
labels along the edges so that as many road sections as possible are identified
by their name, i.e., covered by a label. We show that this is NP-hard in
general, but the problem can be solved in polynomial time if the road map is an
embedded tree.
