Airbag for a vehicle includes at least one section of material defining a plurality of cells, chambers or compartments, and one-way valves arranged in connection with the material section(s) between the cells to control flow of inflating fluid between the cells. Each valve can lead from a respective first cell to a respective second cell and are preferably designed to close once a predetermined pressure prevails in the second cell to prevent fluid outflow from the respective second cell. The cells may be interconnected such that at least one cell is interposed between and connected to two other cells. A plurality of valves may be arranged between adjacent pairs of the cells, or only a single valve may be arranged between an adjacent pair of cells.