  We study the capacitated vehicle routing problem in graphic metrics (graphic
CVRP). Our main contribution is a new lower bound on the cost of an optimal
solution. For graphic metrics, this lower bound is tight and significantly
stronger than the well-known bound for general metrics. The proof of the new
lower bound is simple and combinatorial. Using this lower bound, we analyze the
approximation ratio of the classical iterated tour partitioning algorithm
combined with the TSP algorithms for graphic metrics of Christofides [1976], of
M\"omke-Svensson [JACM 2016], and of Seb\H{o}-Vygen [Combinatorica 2014]. In
particular, we obtain a 1.95-approximation for the graphic CVRP.
