Given a set of n disjoint line segments in the plane, we show that it is al
ways possible to forma tree with the endpoints of the segments such that ea
ch line segment is an edge of the tree, the tree has no crossing edges, and
the maximum vertex degree of the tree is 3. Furthermore, there exist confi
gurations of line segments where any such tree requires degree 3. We provid
e an O(n log n) time algorithm for constructing such a tree, and show that
this is optimal.