The critical resistivity ρ c xx measured along the quantum Hall liquid-insulator transition line indicates a pronounced peak for a critical filling factor νc ∼ 1. The origin of this behavior, which marks the crossover from the high to low magnetic field regime in the phase diagram, is explained in the framework of classical transport in a puddle network model. The proposed scenario is also consistent with the behavior of the critical Hall resistance along the transition line. In addition, a functional form is suggested as a fit for isotherms ρxx(ν), to be compared with experimental data in the moderately high field regime.