In this paper a novel model for the transient simulation of lossy transmission lines is derived by the discretization of the telegrapher's equations on a predefined grid. The technique is based on modifying analytical solutions from lossless lines with terms that capture the effects of loss and dispersion accurately. Unlike conventional finite difference discretization schemes which result in RLCG-networks the new model does not exhibit spurious oscillations and accurate. An a priori estimate of the truncation error is given. The resulting system of equations is independent of the time-step and must, therefore, be evaluated only once. Three variants of the model are discussed and a consistency proof is given. Furthermore, it is efficient with regard to computer time because it does not require numerical integration. The results show the superiority of the new model compared with traditional lumped models.