We study the friction when a rectangular tire tread rubber block is slid on an ice surface at different temperatures ranging from −38○C to −2○C, and sliding speeds ranging from 3 µm/s to 1 cm/s. At low temperatures and low sliding speeds we propose that an important contribution to the friction force is due to slip between the ice surface and ice fragments attached to the rubber surface. At temperatures above −10○C or for high enough sliding speeds a thin premelted water film occur on the ice surface and the contribution to the friction from shearing the area of real contact is small. In this case the dominant contribution to the friction force comes from viscoelastic deformations of the rubber by the ice asperities.