The Linear Arboricity of Series-Parallel Graphs

 The linear arboricity la(G) of a graph G is the minimum number of linear forests which partition the edges of G. A graph is called series-parallel if it contains no subgraphs homeomorphic to K ₄. In this paper, we prove that for any series-parallel graph G having Δ (G)≥3. Since an outerplanar graph is a series-parallel graph, this is also true for any outerplanar graph. Received: August 20, 1997 Revised: March 12, 1999