  In 1965, Vizing proved that every planar graph $G$ with maximum degree
$\Delta\geq 8$ is edge $\Delta$-colorable. It is also proved that every planar
graph $G$ with maximum degree $\Delta=7$ is edge $\Delta$-colorable by Sanders
and Zhao, independently by Zhang. In this paper, we extend the above results by
showing that every $K_5$-minor free graph with maximum degree $\Delta$ at least
seven is edge $\Delta$-colorable.
