The serviceability of flexible pavements in northern environments is an important issue when the effect of frost heave is experienced at the surface of these structures. As frost heave is rarely uniform, the pavement roughness usually increases during winter due to differential frost heave. In this paper, a design methodology for the determination of allowable frost heave based on subgrade soils variability is proposed. The method also allows proposing allowable frost heave criteria based on the presence of buried utilities, which trenches are usually filled with materials non sensitive to frost, in the case of residential and arterial roads in the urban context. The allowable frost heaves are a function of subgrade soils variability, and therefore function of the risk of differential frost heave, and are in good agreement with data found in the literature.