Mode I + II fatigue crack growth tests are run, following sequential or pseudo-sequential loading paths, representative of those computed for ”squat type” cracks in rails. Stereo DIC provides the near-tip displacements,from which ΔKIeffective and ΔKIIeffective are derived. Compression while shearing extends coplanar growth, by slowing down the wear-induced rise of the effective mode mixity ratio, up to the critical value for which bifurcation occurs. The consideration of plasticity and contact and friction stresses improves crack paths predictions,compared to the maximum tangential stress criterion. The coplanar crack growth rate correlates well with a combination of ΔKIeffective and ΔKIIeffective