The finite strip method consists in breaking down the field studied into rectangular elements called: "strip" linked together by means of "nodal" lines. The deflection is transformed into series with a limited number of terms. On each nodal line are two unknown factors: the deflection and the rotation, instead of three as in the finite element method. The width of the half-strip of the stiffness matrix in the finite strip method does not depend on the mesh but on the number of terms in the series. This method was shown to be more economical than the finite element method. It seems to be more efficient and easier for analyzing plates and beams such as in bridges, in particular orthotropic slab bridges, including cantilevered beams. /TRRL/